Griffiths Experiment: Bacterial Transformation @BOGObiology

BOGObiology This video explains Griffith's experiment to prove the existence of a "transformation principle" via experimentation with mice and two kinds of pneumonia bacteria. His work paved the way for Avery, McCarty and MacLeod to later prove the DNA is the molecule of heredity.

Chapters:
0:00-0:06 Introduction
0:06-0:40 S and R Strain of Streptococcus Pneumoniae
0:40-0:58 The Transformation Principle
0:58-1:24 Griffith's Experiment Structure
1:24-1:32 Live R Strain
1:32-1:40 Live S Strain
1:40-2:00 Heat Killed S Strain
2:00-2:30 Heat Killed S Strain, Live R Strain
2:30-2:55 Isolated S Strain
2:55-3:45 Conclusions, Connections to Avery, McCarty and MacLeod's Work

Details:
While observing the pneumococcus bacteria, Griffith noticed that sometimes the non-virulent R strain would revert into the virulent S strain. He theorized that a “transforming principle” was somehow transferred between the S strain and the R strain, causing the R strain to acquire dangerous properties.

To test his theory, he injected five different types of bacteria into groups of mice;
1) Live R strain
2) Live S Strain
3) Heat-Killed S strain
4) a COMBINATION of Heat-killed S strain AND live R-strain
5) S strain that had been isolated from mice in the fourth group.
The results Griffith’s famous experiment would confirm the presence of a “transforming principle”.

Predictably, the mice from group 1 survived, the mice from group 2 died, and the mice from group 3 survived. However, the mice in group 4 died. On their own, neither the heat killed S strain nor the live R strain should have been deadly, so Griffith concluded that the live R-strain had acquired some type of deadly component from the dead S-strain. He called this mystery component the “transformation principle”.

Griffith’s ground-breaking work proved that some organisms can acquire new properties from their environment and from one another, and that non-heritable exchange of genetic information is possible.

Useful Sources:
en.wikipedia.org/wiki/Griffith%27s_experiment
openstax.org/books/microbiology/pages/10-1-using-microbiology-to-discover-the-secrets-of-life

APA Video Citation:
[BOGObiology]. (2021, May 24). Griffith's Experiment: Bacterial Transformation. [Video File]. Retrieved from youtu.be/rMa9MzP19zI

updated 5 years ago

Griffiths Experiment: Bacterial Transformation

BOGObiology 2021-05-24 | This video explains Griffith's experiment to prove the existence of a "transformation principle" via experimentation with mice and two kinds of pneumonia bacteria. His work paved the way for Avery, McCarty and MacLeod to later prove the DNA is the molecule of heredity.

Chapters:
0:00-0:06 Introduction
0:06-0:40 S and R Strain of Streptococcus Pneumoniae
0:40-0:58 The Transformation Principle
0:58-1:24 Griffith's Experiment Structure
1:24-1:32 Live R Strain
1:32-1:40 Live S Strain
1:40-2:00 Heat Killed S Strain
2:00-2:30 Heat Killed S Strain, Live R Strain
2:30-2:55 Isolated S Strain
2:55-3:45 Conclusions, Connections to Avery, McCarty and MacLeod's Work

Details:
While observing the pneumococcus bacteria, Griffith noticed that sometimes the non-virulent R strain would revert into the virulent S strain. He theorized that a “transforming principle” was somehow transferred between the S strain and the R strain, causing the R strain to acquire dangerous properties.

To test his theory, he injected five different types of bacteria into groups of mice;
1) Live R strain
2) Live S Strain
3) Heat-Killed S strain
4) a COMBINATION of Heat-killed S strain AND live R-strain
5) S strain that had been isolated from mice in the fourth group.
The results Griffith’s famous experiment would confirm the presence of a “transforming principle”.

Predictably, the mice from group 1 survived, the mice from group 2 died, and the mice from group 3 survived. However, the mice in group 4 died. On their own, neither the heat killed S strain nor the live R strain should have been deadly, so Griffith concluded that the live R-strain had acquired some type of deadly component from the dead S-strain. He called this mystery component the “transformation principle”.

Griffith’s ground-breaking work proved that some organisms can acquire new properties from their environment and from one another, and that non-heritable exchange of genetic information is possible.

Useful Sources:
en.wikipedia.org/wiki/Griffith%27s_experiment
openstax.org/books/microbiology/pages/10-1-using-microbiology-to-discover-the-secrets-of-life

APA Video Citation:
[BOGObiology]. (2021, May 24). Griffith's Experiment: Bacterial Transformation. [Video File]. Retrieved from youtu.be/rMa9MzP19zI

Plant Root System & Shoot System

BOGObiology 2022-11-28 | Plants have two major organ systems; the root system and the shoot system. These two systems consist of several structures working together in order to absorb nutrients from the environment, to perform photosynthesis and/or to reproduce. Plant structure and function are closely related, as you will see.

The roots are have three major functions: anchoring the plant to the soil, absorbing water and minerals and transporting them upwards to the rest of the plant, and storing the products of photosynthesis. Some types of roots can also perform gas exchange, and a few types of plants have adventitious roots which are at least partially above ground. There are two major types of roots; tap roots and fibrous roots. Tap roots have one major root that grows straight down sometimes with a few smaller branches protruding off of it. Fibrous roots have a network of smaller roots that protrude outwards, usually at a much shallower level.

The shoot system consists of stems, leaves, fruits and flowers (basically any structure that is not a root!) Stems are part of the shoot system of the plant; they provide support and also connect the leaves (where photosynthesis occurs) with the roots (where some of the products are stored). Leaves are the major site of photosynthesis; their cells contain chloroplasts which harness energy from sunlight to produce sugars. Flowers and/or fruits are related organs that are both part of the plant’s reproductive system.

Leaf Structure Video:
youtu.be/_y-HCi7mJjM

C3 vs C4 vs CAM Plant Video:
youtu.be/P_JU9vYd5O0

Photosynthesis Video:
youtu.be/ZKC_aRrf1Rg

Chapters:
0:00-0:20 Introduction
0:20-1:12 Levels of organization
1:13-2:14 Non vascular vs vascular plants
2:14-2:36 Overview of plant organ systems
2:36-3:06 Root system functions
3:06-4:00 Parts of the root system
4:00-4:49 Tap roots
4:49-5:06 Fibrous roots
5:06-5:44 Parts of the shoot system, stem
5:44-6:28 Leaves
6:28-8:00 Fruits & Flowers as related structures

Useful Sources:
1) https://organismalbio.biosci.gatech.edu/growth-and-reproduction/plant-development-i-tissue-differentiation-and-function/
2) openstax.org/books/biology-2e/pages/30-1-the-plant-body#:~:text=Plant%20Organ%20Systems&text=Vascular%20plants%20have%20two%20distinct,which%20include%20flowers%20and%20fruits.

Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:

[BOGObiology]. (2022, November 28). Plant Root System & Shoot System. [Video File]. Retrieved from youtu.be/F1KhtFnfDSg

Fermentation: Lactic Acid, Alcohol & Glycolysis

BOGObiology 2022-04-19 | This video compares the processes of aerobic cellular respiration, lactic acid fermentation, alcoholic fermentation and anaerobic respiration. It reviews glycolysis, which all four processes share, and then the special modifications.

Fermentation is a process that breaks down glucose or other sugars to form a limited amount of ATP without using an electron transport chain. It produces an end product such as lactic acid or ethanol and occurs when there is no oxygen or limited oxygen. Fermentation also regenerates the NAD+ needed to run Glycolysis, allowing the process to repeat and generating 2 ATP each time.

0:00-0:25 Introduction
0:26-0:58 Definitions of Respiration and Fermentation, Obligate vs Facultative Organisms
0:59-1:17 Definitions of Obligate Aerobes, Obligate Anaerobes and Facultative Anaerobes
1:17-1:27 Goal of Fermentation & Respiration
1:28-2:07 Substrate Level Phosphorylation & Oxidative Phosphorylation
2:07-2:32 Oxygen as the Final Electron Acceptor in Aerobic Respiration
2:33-2:47 Fermentation: A Solution in Low or No Oxygen Environments
2:47-4:24 Glycolysis Investment Phase
4:24-4:43 Glycolysis Payoff Phase
4:44-5:17 NADH and NAD+: Mobile Electron Carriers
5:17-5:55 Oxidation of NADH vs Reduction of NAD+
5:55-6:32 Fermentation Overview: A Strategy for Oxidation of NADH
6:32-7:16 Lactic Acid vs Alcoholic Fermentation Examples and Location
7:17-8:52 Lactic Acid Fermentation & The Cori Cycle
8:53-9:48 Alcoholic Fermentation
9:49-11:06 Anaerobic Respiration
11:06-13:38 Summary of Aerobic Respiration, Lactic Acid Fermentation, Alcoholic Fermentation & Anaerobic Respiration

Useful Sources For Further Reading:
Fermentation: openstax.org/books/concepts-biology/pages/4-4-fermentation#:~:text=Processes%20that%20use%20an%20organic,)%20to%20achieve%20NAD%2B%20regeneration.

Obligate Anaerobic Metabolism: ncbi.nlm.nih.gov/books/NBK7919/#:~:text=For%20anaerobic%20respiration%2C%20NO3,2%20and%20H2O.

Cori Cycle: en.wikipedia.org/wiki/Cori_cycle

Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:

[BOGObiology]. (2022, April 18). Hypertonic, Hypotonic and Isotonic Solutions!. [Video File]. Retrieved from youtu.be/rMa9MzP19zI

C3, C4 and CAM Plant Photosynthesis & Photorespiration

BOGObiology 2022-03-29 | C3 Photosynthesis, C4 Photosynthesis and CAM Photosynthesis are all related, but have some critical differences. This video compares and contrasts them, and explains how C4 and CAM photosynthesis help plants to avoid the wasteful process of photorespiration. It also covers C3 C4 and CAM leaf anatomy, example plants, key cells, and the ideal temperature range for each plant type. Finally, the video covers practical applications for using this information in your research or business in order to optimize crop yield.

C3 Photosynthesis (considered the standard) is highly efficient, so long as an ample supply of CO2 is available. However, the C3 Calvin Cycle uses an enzyme known as RuBisCO, which is prone to binding to oxygen under certain conditions, particularly if the weather is hot. This triggers an extremely inefficient process called photorespiration; the plant can still photosynthesize but only at a reduced rate of about 75%. In addition, the process produces waste, and costs more ATP. C4 and CAM Plants are specialists at avoiding photorespiration, and have a number of useful mechanisms and structures for doing it. Both specialized processes cost ATP, but they are still far more efficient than photorespiration.

C4 plants split the process of carbon fixation and the Calvin Cycle into two separate cells; palisade mesophyll and bundle sheath cells, respectively. This keeps RuBisCO from coming into contact with oxygen. C4 Plants also have Kranz anatomy, where the palisade mesophyll cells and bundle sheath cells are close together to facilitate this process.

CAM Plants collect CO2 at night when the air is cooler and having stomata open is less risky. They "fix" CO2 into malate or other organic acids, which are stored until the next day. The acids are then split into carbon dioxide, which feeds the Calvin Cycle, and pyruvate which is re-invested to keep the nighttime fixation process going. CAM Plants also store water when they have a chance, usually in structures called aquiferous parenchyma.

This information can be highly useful to anyone attempting to grow crops; matching the crop to the local environment is essential in order to maximize yield. If the plants are to be grown in a greenhouse, first priority is to ensure water and sunlight, second priority is to optimize the temperature to the plant type, and third priority is to consider supplements such as CO2 in order to boost the rate of photosynthesis and minimize photorespiration.

0:00-0:19 Introduction
0:19-1:07 Photosynthesis and Carbon Fixation Overview
1:07-2:22 C3 Photosynthesis & RuBisCO
2:22-4:00 What is Photorespiration?
4:00-5:00 Relationship between Photorespiration and Temperature
5:00-7:24 C4 Photosynthesis
7:24-8:37 CAM Photosynthesis
8:37-9:35 C3 C4 CAM Leaf Structure and Anatomy
9:35-10:35 Practical Application: Optimizing Setup
10:35-11:57 Limiting Factors to Photosynthesis
11:57-14:04 Cost-Benefit Analysis of Adding CO2

Useful Sources:
onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2007.01682.x
http://ib.berkeley.edu/courses/ib151/IB151Lecture6.pdf
byjus.com/neet/difference-between-c3-c4-and-cam-pathway
http://www.omafra.gov.on.ca/english/crops/facts/00-077.htm

Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:
[BOGObiology]. (2022, March 29). C3, C4, CAM Plant Photosynthesis & Photorespiration Explained. [Video File]. Retrieved from youtu.be/P_JU9vYd5O0

PCR (Polymerase Chain Reaction) Explained

BOGObiology 2022-02-28 | Polymerase Chain Reaction (PCR), is a genetic copying process used in biotechnology. This video covers what PCR is, what it is used for, the reagents of PCR, the steps of PCR, and how RT-qPCR is used in Covid testing.

PCR REAGENTS:
DNA Sample: Contains the sequence of interest to be copied
Taq Polymerase: Enzyme that will build the new DNA strands
Deoxynucleoside Triphosphatases: Building blocks for the new strands
Primers: Single stranded sequences that bracket the sequence of interest
Buffer Solution: Maintains optimal conditions for the reaction to occur
Magnesium Cofactors: Helps the primers to adhere at the correct site, and it helps Taq Polymerase to function optimally

PROCESS OF PCR:
PCR has 3 phases: Denaturation, Annealing and Extension. During the Denaturation Phase, the DNA strands are separated using heat, creating two new template strands. During the Annealing Phase, primers adhere to the start of the sequence of interest, marking where the Taq Polymerase should begin building. During the Extension Phase, the Taq Polymerase builds new complementary DNA strands, using the template strands as a guide. At the end of the cycle, the amount of DNA has doubled.

HOW IS PCR USED IN COVID TESTING?
PCR testing for the virus uses a modified version of PCR called RT-qPCR (reverse transcription quantitative PCR). This type of PCR uses a naturally occurring enzyme called Reverse Transcriptase to convert single stranded viral RNA into double stranded DNA suitable for PCR. Dye is added to the reaction that will fluoresce in the presence of viral DNA. As the cycles progress and the amount of viral DNA (if any) continues to double, the sample will glow brighter and brighter. A computer tracks the level of fluorescence and labels a sample as positive if the brightness exceeds a particular threshold. The two major types of fluorescent dye methods are SYBR Green, and Taqman Probe Assays.

0:00-0:16 Introduction
0:17-0:56 What is PCR?
0:57-1:35 Uses of PCR: Forensics, Agriculture & Medicine
1:35-1:46 Reagents of PCR: Overview
1:46-1:53 DNA Sample in PCR
1:53-2:16 Taq Polymerase in PCR
2:16-2:32 DNTPs in PCR
2:32-2:54 PCR Primers
2:55-3:16 PCR Buffer
3:16-3:29 PCR Magnesium Cofactors
3:30-3:53 PCR vs DNA Replication
3:53-4:16 Denaturation Phase of PCR
4:17-5:41 Annealing Phase of PCR
5:41-6:22 Extension Phase of PCR
6:23-6:50 Exponential Growth
6:50-7:16 RT-qPCR in Covid Testing
7:16-8:02 Reverse Transcription in RT-qPCR for Covid Testing
8:02-8:52 Quantitative PCR for Covid Testing
8:52-9:52 SYBR Green and TaqMan Probe Assays in Covid Testing
9:52-10:49 False Positives vs False Negatives

USEFUL SOURCES FOR FURTHER READING:
PCR:
en.wikipedia.org/wiki/Polymerase_chain_reaction
openstax.org/books/biology-2e/pages/17-1-biotechnology

DNA Replication:
openstax.org/books/biology-2e/pages/14-3-basics-of-dna-replication

Taq Polymerase:
en.wikipedia.org/wiki/Taq_polymerase

PCR Covid Testing:
genome.gov/about-genomics/fact-sheets/Understanding-COVID-19-PCR-Testing
ncbi.nlm.nih.gov/pmc/articles/PMC7831559

CITATION:
Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:
[BOGObiology]. (2022, February 28). PCR (Polymerase Chain Reaction) Explained. [Video File]. Retrieved from youtu.be/8GOKaZ8MRyM

#PCR #covidtest #polymerasechainreaction

Gel Electrophoresis and DNA Fingerprinting Explained

BOGObiology 2022-01-10 | Gel Electrophoresis, sometimes called "DNA Fingerprinting", separates molecules using size and charge. It is a common method of analysis in biology and biotechnology. Combined with DNA ladders and restriction enzymes, we can quickly and cheaply analyze and compare DNA samples.

0:00-0:23 Introduction
0:23-0:55 What is Gel Electrophoresis?
0:55-1:52 Gel Electrophoresis: A Molecular Obstacle Course
1:53-2:05 Steps of Gel Electrophoresis Overview
2:06-2:41 Pouring the Gel
2:42-3:04 Preparing the Samples
3:05-3:46 Loading the Gel
3:47-4:38 Running the Gel
4:39-5:13 Staining the Gel
5:13-5:47 Interpreting the Gel
5:48-6:29 DNA Ladder
6:30-8:27 Restriction Enzymes
8:27-8:57 Enzyme Star Activity
8:58-9:34 Applications of Gel Electrophoresis
9:35-11:49 King Tut and DNA Analysis

Sources:
Gel Electrophoresis: http://www.columbia.edu/itc/barnard/biology/biobc2004/edit/experiments/Experiment5-Gel.pdf
edvotek.com/109

Restriction Enzymes:
sciencedirect.com/topics/immunology-and-microbiology/restriction-site#:~:text=A%20restriction%20site%20is%20a,by%20cleaving%20the%20viral%20DNA.

EcoR1:
en.wikipedia.org/wiki/EcoRI

King Tut:
http://www.leben-in-luxor.de/docs/Hawass_Ancestry_and_Pathology_joc05008_638_647.pdf

Paternity testing:
en.wikipedia.org/wiki/DNA_paternity_testing

Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:

[BOGObiology]. (2022, January 10). Hypertonic, Hypotonic and Isotonic Solutions!. [Video File]. Retrieved from youtu.be/N3TrRc9CL9w

#gelelectrophoresis #biotech #lab

Properties of Water

BOGObiology 2021-12-01 | This video examines water's structure and polarity, its tendency to form hydrogen bonds, and the high specific heat, cohesion, adhesion, surface tension and capillary action that all result from these hydrogen bonds. Water is such a common molecule that we often don’t think about it, but it has many properties that make it crucial for many biological processes.

Water Structure:
The water molecule is shaped like the letter V, with an oxygen in the center and two hydrogens joined to it by single covalent bonds. Both atoms contribute electrons to the covalent bonds, but the distribution is not equal. Overall the electrons spend more time close to oxygen than they do to hydrogen. This is because oxygen has a higher tendency to attract electrons, a property that we call “electronegativity” .

Water Polarity:
Why is water polar? Since electrons have a negative charge and they spend a larger part of their time near oxygen, it gives the oxygen a partial negative charge, and the hydrogens a partial positive charge. When a molecule has more positive and more negative regions, we say it is “polar”.

Hydrogen Bonds:
Why does water form hydrogen bonds? Oppositely charged parts of water molecules are attracted to one another (negative oxygen and positive hydrogen) in what we call hydrogen bonds. It’s very important to remember that water REALLY likes to form hydrogen bonds. One water molecule can form up to four at a time. In liquid water, the hydrogen bonds are weak and last just a fraction of a second before they reform in another configuration. This constant breaking, rearranging and reforming of hydrogen bonds causes many of water’s unique properties, including its heat capacity, cohesion, adhesion, surface tension and capillary action.

Specific Heat Capacity:
Why does water have high specific heat capacity? Thanks to its hydrogen bonds, water can absorb a very large amount of heat energy without changing into a gas. Water has a high specific heat capacity, which means it needs a lot of heat in order to raise the temperature of 1 gram of water by 1 degree celsius. In short, because water really loves to form hydrogen bonds, it takes a LOT of heat energy to overcome this tendency, break the bonds and make water warm up.

Cohesion:
Water has a tendency to stick to itself because it easily forms these hydrogen bonds. At any point, a large percentage of water molecules hydrogen bonding with several neighbors. We call this tendency of water to stick to itself “cohesion”.

Surface Tension:
Usually, each water molecule is bonded to four other water molecules most of the time, and the force is the same in all directions. However, at the surface of the water, the outer molecules have fewer adjacent water molecules to bond to. So, instead they reinforce the bonds with the molecules next to them. Because there are forces pulling the outermost molecules down and to the side, but not up, it creates a stronger layer on the surface, and a net force that pulls molecules inwards. Because water really loves to form hydrogen bonds, the top layer is reinforced, creating surface tension.

Adhesion:
Water also has a tendency to stick to other polar objects. We call this behavior “adhesion”. Because water really loves to form hydrogen bonds, the water adheres weakly to a waxy surface, but strongly to itself, forming a rounded water bead instead of a puddle.

Capillary Action:
The combination of cohesion, adhesion and surface tension creates capillary action. This is when a liquid flows through a narrow space without any external forces like gravity. In capillary action, adhesion to the walls of a vessel is stronger than the cohesion between the water molecules. The liquid sticks to the walls then pulls other molecules up behind it, then climb higher, like a rock climber. If the diameter of the tube is too big, the molecules cannot climb the walls. Instead, they go as high as they can before gravity overpowers the adhesive and cohesive forces and stops the liquid moving up. This results in a “dip” called a “meniscus”.

Chapters:
0:00-0:25 Introduction
0:25-0:39 Structure
0:39-1:04 Covalent Bonds
1:04-1:32 Electronegativity
1:32-1:56 Polarity
1:56-3:05 Hydrogen Bonds
3:05-4:11 Specific Heat
4:11-4:38 Cohesion
4:38-5:24 Surface Tension
5:24-5:55 Adhesion
5:55-7:30 Capillary Action
7:30-7:47 Conclusion

Sources:
openstax.org/books/biology-2e/pages/2-2-water

chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/Atomic_and_Molecular_Properties/Dipole_Moments

openstax.org/books/college-physics/pages/11-8-cohesion-and-adhesion-in-liquids-surface-tension-and-capillary-action

Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:
[BOGObiology]. (2021, December 1). Properties of Water. [Video File]. Retrieved from youtu.be/qcePiG28Mkc

#water #hydrogenbonds #chemistry

Hershey and Chase Experiment: DNA is the Molecule of Heredity

BOGObiology 2021-11-17 | The classic Hershey and Chase Experiment proved conclusively that DNA was the molecule of heredity in 1952.

Dr. Alfred Hershey and Dr. Martha Chase’s now famous experiment was actually the third major investigation into what genes are made of. They learned from the previous work of Frederick Griffith in 1928 and Oswald Avery, Colin MacLeod and Maclyn McCarty in 1944.

Griffith's Experiment Video: youtu.be/92HWRdvDF_s

Avery Experiment Video: youtu.be/fci1oS1kofs
Avery Experiment Handout: etsy.me/3DvLDv6

Hershey and Chase harnessed the viral life cycle to prove which of the two contenders was actually responsible for inheritance; proteins or nucleic acids. Hershey and Chase used two groups of bacteriophages, and made a single component radioactive in each one to keep track of what it was doing. In one group, they tested the viral protein coat on the outside, and in the other group they tested the nucleic acids on the inside of the virus.

The experiment consisted of three major steps; infection, blending, and centrifugation. In the infection step, Hershey and Chase then allowed each type of bacteriophage to infect a host cell to see whether the radioactive proteins or the radioactive nucleic acids would make radioactive bacteriophages. Next, in the blending step, they used a high speed blender to jiggle the e coli cells enough to shake off the empty protein shell from the outside. (This is why this experiment is sometimes affectionately referred to as the “Blender Experiment”). This created a mixture of liquid, phage parts and bacteria called a “suspension”. Finally, in the centrifugation, they spun this mixture in a centrifuge so that the heavier bacteria condensed and formed a pellet at the bottom of the test tube. Since the virus particles were much smaller and lighter, they remained suspended in the liquid or the “supernatant”.

Hershey and Chase found that the supernatant was more radioactive in the protein group, and the pellet was more radioactive in the nucleic acid group, indicating that the viral DNA had entered the cell. This provided very compelling evidence that nucleic acids, not proteins, were the molecule of inheritance.

0:00-0:11 Introduction
0:11-0:34 Biomolecules
0:34-1:28 Griffith's Transforming Principle Experiment
1:29-2:11 Avery Experiment Claims DNA is the Transforming Principle
2:11-3:54 Hershey and Chase Harness T4 Bacteriophages
3:55-4:38 Key Elements of Proteins and Nucleic Acids
4:39-5:28 Hershey and Chase Experiment Design
5:29-6:26 Hershey and Chase Experiment Results
6:27-6:42 Response to the Hershey and Chase Experiment
6:43-7:00 Nobel Prize committee snubs Dr. Martha Chase
7:00-7:14 Conclusion

Avoid plagiarism! Cite BOGObiology! Copy and Paste the Following APA Citation:

[BOGObiology]. (2021, November 17). Hershey and Chase Experiment: DNA is the Molecule of Heredity. [Video File]. Retrieved from youtu.be/wSjlip4iY0s

#hersheychase #dna #moleculeofheredity

Avery Experiment: DNA as the Transforming Principle

BOGObiology 2021-10-17 | The Avery, MacLeod and McCarty classic experiment helped to prove that DNA is the molecule of heredity. Previously, it was thought that proteins were the most likely biomolecule that transferred inheritance information from parent to offspring.

Avery's experiment built on the foundation of Griffith's earlier work, in which he identified a "transforming principle" that allowed bacteria to acquire characteristics from one another. In the Avery experiment, they first used process of elimination to determine that neither carbohydrates nor lipids were responsible, then tested proteins, RNA and DNA. The scientists knew that bacterial transformation should still take place unless they disabled the transforming principle. They added enzymes such as proteases, RNases and DNases to destroy various components of the bacterial mixture, knowing that most mice would die except the mice who received the injection with the disabled transforming principle.

Guided Notes & Study Guide: Check out the BOGOnotes for this video!
etsy.me/3wlfh3g

0:00-0:38 Introduction
0:38-0:55 Biomolecules
0:55-1:47 Proteins vs. Nucleic Acids
1:48-2:30 Building on Griffith's Experiment on Bacterial Transformation
2:30-3:50 Preliminary Testing
3:50-4:03 The Diva Protein
4:03-4:26 Process of Elimination
4:26-4:57 Avery Experiment Design
4:57-6:24 Avery Experiment Results
6:24-7:12 Conclusions

Sources:
The Original Paper: ncbi.nlm.nih.gov/pmc/articles/PMC2135445/pdf/137.pdf

en.wikipedia.org/wiki/Avery%E2%80%93MacLeod%E2%80%93McCarty_experiment#:~:text=The%20Avery%E2%80%93MacLeod%E2%80%93McCarty%20experiment,the%20function%20of%20carrying%20genetic

openstax.org/books/microbiology/pages/10-1-using-microbiology-to-discover-the-secrets-of-life

thebiotechnotes.com/2019/12/09/averys-experiment

#averyexperiment #bacterialtransformation #moleculeofheredity

Leaf Structure and Function

BOGObiology 2021-05-11 | Leaves come in many shapes and sizes. This video walks through the major internal cell types, including the waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, vascular bundle, xylem, phloem, bundle sheath cells, stomata and trichomes. It reviews the structure and function of each component, and connects each back to the process of photosynthesis, including the specialized C4 Pathway.

Photosynthesis Study Guide: etsy.me/2M9R8ak

Chapters:
00:00-00:19 Introduction
00:19-00:32 Reagents and Products of Photosynthesis
00:32-00:44 Types of Leaves
00:44-1:01 Waxy Cuticle
1:02-1:22 Upper Epidermis
1:22-1:47 Palisade Mesophyll/Palisade Parenchyma
1:48-2:11 Spongy Mesophyll/Spongy Parenchyma
2:12-2:33 Vascular Bundle: Xylem
2:33-2:46 Vascular Bundle: Phloem
2:47-3:07 Vascular Bundle: Bundle Sheath Cells
3:08-3:17 Lower Epidermis
3:18-3:49 Stomata & Guard Cells
3:50-4:14 Carbon Fixation in the Calvin Cycle
4:14-4:41 C4 Pathway: Dry Climate Adaptations
4:41-5:27 Trichomes & Terpenes
5:28-5:33 Review Questions

Waxy Cuticle:
Hydrophobic waxy layer that minimizes water loss via transpiration

Upper Epidermis:
Tightly packed translucent cells to minimize water loss via transpiration

Palisade Mesophyll:
Tightly packed column shaped cells, which are the main site of photosynthesis. They contain many chloroplasts.

Spongy Mesophyll:
Loosely packed irregular cells containing a few chloroplasts. The air space in between allows for gas exchange.

Vascular Bundle:
Set of tissues that transport products around the plant

Xylem:
Upward flowing tubes that transport water from the roots to the leaves

Phloem:
Up and down flowing tubes that transport glucose and other products of photosynthesis from the leaves to the rest of the plant.

Bundle sheath cells:
Tightly packed cells surrounding the vascular bundle, which can play a key role in photosynthesis in hot dry environments

Stomata:
These openings allow gas exchange in and out of the leaf. The guard cells open and close in response to the environment.

Trichomes:
Tiny hair-like protrusions on leaf surfaces. These can deter insects, and some contain strong-smelling compounds known as terpenes. Some common terpenes include those found in citrus fruits, pine, lavender and tetrahydrocannabinol (THC).

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[BOGObiology]. (2021, May 11). Leaf Structure and Function. [Video File]. Retrieved from youtu.be/_y-HCi7mJjM

NGSS: HS-LS1-5

The Heart and Circulatory System Structure and Function

BOGObiology 2021-04-17 | This video introduces the heart and circulatory system. It covers the structure and function of the circulatory system, compares and contrasts the types of blood vessels (arteries, veins and capillaries), and explains the internal structure of the heart. The video also reviews the path of blood through the heart, the cardiac cycle, the process of oxygenation, and the role of the coronary vessels and nodes.

"BOGOnotes" Study Guide: etsy.me/3v1hbnW

00:00-0:24 Introduction
0:25-1:25 The Circulatory System
1:25-2:12 Types of Blood Vessels: Arteries
2:12-2:54 Types of Blood Vessels: Veins
2:54-3:27 Types of Blood Vessels: Capillaries
3:27-3:54 The Cardiac Cycle
3:55-6:49 Path of Blood Through the Heart
6:50-7:14 The Coronary Vessels
7:15-8:47 The Nodes and Cardiac Conduction

The Circulatory System Loops:
The circulatory system delivers blood to every part of the body. It has three loops; the pulmonary loop which oxygenates the blood in the lungs, the systemic loop which circulates blood throughout the body, and the coronary circuit which supplies blood to the heart muscles.

The Cardiac Cycle:
The heart pumps blood through the body in a repeating process called the Cardiac Cycle. During the Cardiac Cycle, the chambers of the heart rhythmically contract (systole) and relax (diastole). During systole, the heart pushes blood out through its major vessels, and the relaxation of diastole allows the chambers to refill; much like an ordinary pump that you might use to inflate a bicycle tire.

Types of Blood Vessels:
Arteries: Arteries carry blood away from the heart. Usually this means they carry oxygenated blood, but not always. Artery walls consist of three layers of tissue, and arteries also have the thickest, most muscular walls of all the blood vessels because the pressure in them is quite high. Some arteries you might have heard of are the aorta, and also the carotid arteries which run up each side of your neck to supply blood to your brain. The major arteries split into minor arteries, and then into even smaller ones known as arterioles.

Veins: Veins carry blood back to the heart, meaning they USUALLY carry de-oxygenated blood. Veins have 3 layers of wall tissue, but do no not need to be as muscular because the pressure in them is much lower. They also have valves to prevent back-flow because the pressure in them is much lower. A vein you’ve probably heard of is the jugular vein, which runs down the right side of your neck to return blood from the head back to the heart. The major veins split into minor veins, and then into even smaller ones known as venules.

Capillaries: Capillary “beds” are groups of 10-100 tiny blood vessels that branch out from arterioles. Red blood cells can fit through them single file. Because they are so small and have such thin walls, oxygen, carbon dioxide and nutrients can easily diffuse in and out of them through their walls.

Path of Blood Through the Heart:
De-oxygenated blood is funneled back to the heart through a blood vessel called the vena cava. The de-oxygenated blood enters the heart’s right atrium. When the right atrium contracts, it pushes blood into the next chamber, the right ventricle, through a one-way valve called the tricuspid valve (sometimes also called the atrioventricular valve). The valve has flaps that seal tightly to make sure the blood can’t flow backwards. Once the right ventricle is full, it pumps the de-oxygenated blood out towards the lungs so it can be oxygenated. This blood passes through a second valve called the pulmonary valve and into a blood vessel called the pulmonary artery. Even though this pair of blood vessels is carrying de-oxygenated blood, the flow travels away from the heart, so it’s an artery, not a vein.

Once the blood reaches the lungs, gas exchange occurs. The oxygenated blood returns from the lungs via the pulmonary veins. Again, these are flowing back towards the heart, so these blood vessels are veins, even though the blood in them is oxygenated. The blood re-enters the heart in the left atrium. When the atria next contract, the blood is pushed through the mitral valve into the left ventricle. This valve has two flaps, so it’s sometimes also called the “bicuspid valve”. Finally, the left ventricle contracts and forces blood out into the aorta through the aortic valve.

This video covers content that appears on the AP Biology exam, IB exam, NREMT exam and Biology SAT.

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[BOGObiology]. (2021, April 18). The Heart and Circulatory System. [Video File]. Retrieved from youtu.be/Z-DMRsmppA4

#heart #circulatorysystem #anatomy

How to Calculate Percent Change

BOGObiology 2021-02-22 | Calculating percent change, especially calculating it as part of a word problem, is a crucial skill! Percent change (also known as "relative change" or "percent increase/decrease") is useful in every branch of science from Astronomy to Zoology. It's also useful for de-bunking clickbait, as we'll see in this video!

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[BOGObiology]. (2021, February 21). How to Calculate Percent Change Word Problems. [Video File]. Retrieved from youtu.be/sCSgDcBiyUA

Natural Selection, Adaptation and Evolution

BOGObiology 2020-07-30 | This video tutorial covers the concepts of Natural Selection, Adaptation, Evolution and Fitness. It reviews how to interpret population graphs, provides examples of directional selection, stabilizing selection and disruptive selection, and also addresses several misconceptions about how natural selection works.

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[BOGObiology]. (2020, July 30). Natural Selection, Adaptation and Evolution. [Video File]. Retrieved from youtu.be/WmTlwD2Zd7E

#evolution #naturalselection #adaptation

Contents of this video:
00:00-00:20 Introduction
00:20-1:12 Fitness
01:13-2:32 Natural Selection & Adaptation
2:32-2:59 Misconception #1: Individuals Evolve
2:59-3:29 Sources of Genetic Variation
3:29-4:01 Misconception #2: Variation is Goal-Directed
4:01-4:25 Misconception #3: Survival of the Fittest
4:25-5:16 Population Graphs
5:16-6:31 Directional Selection
6:31-7:31 Stabilizing Selection
7:31-9:10 Diversifying/Disruptive Selection
9:10-10:33 Darwin Awards for Human Stupidity

Going Viral: Viruses, Replication and COVID-19

BOGObiology 2020-03-30 | This video reviews the fundamental concepts surrounding viruses. It covers viral structure, the Lytic Cycle and Lysogenic Cycles of virus replication, types of vaccines, antiviral drugs and, of course the novel coronavirus and COVID-19.

Video Chapters
0:00-0:38 Introduction
0:38-1:28 What are viruses?
1:28-2:19 Virus Morphology
2:19-2:45 Viral Capsids
2:45-3:05 Viral Hosts
3:05-3:47 COVID-19
3:47-3:58 Viruses Hijacking Cells
3:58-4:22 Are Viruses Alive?
4:22-5:41 Lytic Cycle of Viral Replication
5:41-6:39 Lysogenic Cycle of Viral Replication
6:39-6:58 Preventing Infections
6:58-8:14 Types of Vaccines
8:14-9:18 Antiviral Medications (e.g. Tamiflu and NRTIs)

Virus structures include helical viruses, polyhedral viruses, spherical viruses (which includes coronaviruses) and complex viruses. Helical viruses include the tobacco mosaic virus. Polyhedral viruses include polio, hepatitis A, B & C, and adenoviruses. Spherical viruses include the novel coronavirus SARS-CoV-2, which causes COVID-19, in addition to influenza. Complex viruses include the T4 bacteriophage.

Replication can involve the lytic cycle either independently or in conjunction with the lysogenic cycle. In the lytic cycle, a virus attaches to a host, replicates, then the cell bursts and releases still more viruses. The lysogenic cycle includes adding a piece of bacterial genetic material into the host cell's genome.

This video also reviews the principles behind vaccines and antiviral medications, such as Tamiflu.

SOME OF THE SOURCES I USED TO MAKE THIS VIDEO:
VIRUSES:
CDC: Antigenic Characterization cdc.gov/flu/about/professionals/antigenic.htm
UC Berkeley
https://ucmp.berkeley.edu/alllife/virus.html
Scientific American
scientificamerican.com/article/are-viruses-alive-2004

VACCINES:
CDC: “How do Vaccines help babies fight infections” youtube.com/watch?v=k7DGeWlKu0Q
Medline.gov:
medlineplus.gov/ency/article/002024.htm

ANTI-VIRALS:
Harvard: What you should know about antiviral drugs https://www.health.harvard.edu/drugs-and-medications/what-you-should-know-about-antiviral-drugs

Contents of this video:
00:00 - Intro
00:39 - What is a Virus?
01:34 - Virus Morphology
2:45 - COVID 19
3:47 - Virus Replication Lytic Cycle
5:49 - Virus Replication Lysogenic Cycle
6:39 - Combatting Viruses
6:58 - Introduction to Vaccines
7:20 - Types of Vaccines
8:14 - Anti-Viral Drugs

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[BOGObiology]. (2020, March 29). Going Viral: Viruses, Replication and COVID-19. [Video File]. Retrieved from youtu.be/b1_pWNUDxSo

Cellular Respiration: Glycolysis, Krebs Cycle & the Electron Transport Chain

BOGObiology 2019-09-02 | Summary Of Cellular Respiration: This video covers all the steps of cellular respiration from start to finish! Organisms perform respiration to create ATP. The reagents of respiration are glucose and oxygen. The products are ATP, carbon dioxide and water.

"BOGOnotes" Study Guide & Diagrams Available Here! etsy.me/2UrGL4b

0:00-0:59 Introduction to Cellular Respiration and Why It's Important
0:59-1:22 Equations, Reagents and Products
1:23-1:49 Aerobic vs Anaerobic Respiration
1:50-2:39 Phases and Location of Cellular Respiration
2:39-5:53 Glycolysis & Prep Steps
5:54-8:57 Krebs Cycle
8:57-14:22 Electron Transport Chain
14:22-14:38 Summary

Glycolysis takes place in the cytoplasm. In glycolysis, glucose is broken down into pyruvate, and then into Acetyl CoA. The process generates a net profit of two ATP, plus some NADH and carbon dioxide.

In the Krebs Cycle within the mitochondrial matrix, the Acetyl CoA is added to Oxaloacetate in a cyclical set of reactions. These reactions generate a few more ATP plus a load of NADH and FADH2.

Finally, the Electron Transport Chain creates a proton gradient across the membrane separating the mitochondrial matrix from the intermembrane space. The proton gradient is created with products transported by NADH and FADH2. The gradient then forces protons through a protein called ATP Synthase, recharging many molecules of ATP. Oxygen functions as the final electron acceptor to absorb the electrons that are exiting the Electron Transport Chain.

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[BOGObiology]. (2019, September 2). Cellular Respiration: Glycolysis, Krebs Cycle & the Electron Transport Chain. [Video File]. Retrieved from youtu.be/2_ceHsFmLVk

#cellularrespiration #glycolysis #krebscycle #electrontransportchain

NGSS: HS-LS1-7

Photosynthesis: The Light Reactions and The Calvin Cycle

BOGObiology 2019-01-14 | Summary Of Photosynthesis: This video covers all the steps of photosynthesis from start to finish! Plants perform photosynthesis to create sugars. The reagents of photosynthesis are photons of light, water and carbon dioxide. The products are Oxygen, Glucose (a sugar) and a bit of water vapor.

Detailed "BOGOnotes" Study Guide available for download here! etsy.me/2M9R8ak

0:00-1:05 Introduction to Photosynthesis
1:05-1:25 Reagents and Products of Photosynthesis
1:26-2:43 Location of Photosynthesis
2:43-3:25 Proteins of the Light Dependent Reactions
3:25-4:32 Photolysis
4:33-7:50 The Electron Transport Chain (aka the Light Dependent Reactions)
7:51-12:50 The Calvin Cycle (aka the Light Independent Reactions)
12:51-13:32 Summary

The Light Dependent Reactions take place across the Thylakoid membrane in the inner compartment of the chloroplasts. These reactions take in sunlight and water and generate ATP, NADPH and Oxygen. Oxygen is released through the plants’ stomata, and the ATP and NADPH are used later in the Calvin Cycle.

In the Light Dependent Reactions, photons of light strike two photosystems, as well as molecules of water. The water molecule splits into oxygen, protons and electrons in a process called “photolysis”. The oxygen diffuses out, the protons are used to establish an electrochemical gradient, and the electrons enter the electron transport chain. In the ETC, an electron is transferred from protein to protein, causing more and more protons to be pumped into the thylakoids. The electrons are ultimately transferred to NADP+ and then moved to the Calvin Cycle. The proton gradient is exploited to generate ATP using ATP synthase. The ATP will also be used later in the Calvin Cycle.

The Calvin Cycle (aka the Light Independent Reactions) takes place in the stroma; the open space inside the chloroplasts. The process combines RuBP and Carbon Dioxide using an enzyme called RuBisCo, a process we call “Carbon Fixation”. Then, it adds Hydrogen and electrons from NADPH and uses energy from ATP to reshuffle the molecules into Glyceraldehyde 3-phosphate, aka “G3P” aka “PGAL”. Two PGAL molecules are set aside to produce Glucose, while the remaining 10 are “reinvested” into the Cycle to keep it turning. The chemical reactions use both the ATP and NADPH that were generated in the Light Dependent Reactions.

C3, C4, CAM Plants Video Tutorial: youtu.be/HbLg4lMpUa8

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[BOGObiology]. (2018, January 14). Photosynthesis. [Video File]. Retrieved from youtu.be/rMa9MzP19zI

#photosynthesis #lightdependentreactions #calvincycle #electrontransportchain #carbonfixation

NGSS: HS-LS1-5

Phases of Mitosis and Cell Division

BOGObiology 2018-11-25 | This video covers the process of Mitosis and Cell Division. It covers the three parts of Interphase (G1 phase, S Phase and G2 Phase) followed by the phases of mitosis; Prophase, Prometaphase, Metaphase, Anaphase and Telophase/Cytokinesis.

It also covers what organisms do mitosis and what happens when mitosis goes wrong by reviewing non-disjunction, aneuploidy and cancer.

00:00-00:24 Introduction
00:24-1:47 Purpose of Mitosis
1:47-2:10 What Organisms do Mitosis?
2:10-2:28 Phases of Mitosis
2:28-3:33 Interphase (G1, S, G2 Phases)
3:34-4:09 Prophase
4:09-4:24 Prometaphase
4:24-4:45 Metaphase
4:45-5:03 Anaphase
5:03-5:33 Telophase
5:33-6:03 Recap of M Phase
6:03-7:36 When Mitosis Goes Wrong; Cancer and Aneuploidy

#mitosis #celldivision #biology

Hypertonic, Hypotonic and Isotonic Solutions!

BOGObiology 2018-10-28 | This video is a review of hypotonic, hypertonic and isotonic solutions, how they lead to plasmolysis, cytolysis and dynamic equilibrium. In addition to tonicity, the video also covers concentration gradients, solutes and solvents, and whether you should drink salt water in a survival situation.

Remember that "hypertonic", "hypotonic" and "isotonic" are all relative terms (like "bigger" or "shorter"). A hypertonic solution is saltyER than something else (in this case, the cell that's placed in it). It might not be very salty at all, it just has to be MORE salty relative to another solution or object.

These concepts are extremely useful in medicine. IV fluids, for instance need to be the correct tonicity in order to achieve the desired effects.

"BOGOnotes" Study Guide Available Here! etsy.me/2MdYmdv

0:00-0:15 Should You Drink Sea Water?
0:21- 0:33 Picky Cells
0:33-0:46 Types of Solutions
0:46-1:10 The Cell Membrane
1:10-1:44 Concentration, Diffusion and Dynamic Equilibrium
1:44- 2:11 Ion Dipole Interactions
2:11- 3:10 Hypertonic Liquid & Plasmolysis
3:10- 3:30 Hypotonic Liquid & Cytolysis
3:30-3:51 Isotonic Liquid
3:52-4:46 Should You Drink Sea Water?

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[BOGObiology]. (2018, October 28). Hypertonic, Hypotonic and Isotonic Solutions!. [Video File]. Retrieved from youtu.be/rMa9MzP19zI

#hypertonic #hypotonic #isotonic #solute #solvent #tonicity

What is the Human Genome Project?

BOGObiology 2018-08-23 | A 1-minute overview of the Human Genome Project! What is the Human Genome Project? What are the benefits of sequencing the human genome?

#humangenomeproject #dna #genetics

DNA Mutations

BOGObiology 2018-08-23 | A 1 minute overview of DNA mutations! Mutations can be inherited or acquired, and some are more destructive than others. One thing is for sure, though, without mutations life as we know it wouldn't exist!

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[BOGObiology]. (2020, January 1). DNA Mutations. [Video File]. Retrieved from youtu.be/pS0nVddeFzs

#dna #mutation #genetics

What is DNA?

BOGObiology 2018-08-23 | A 1-minute overview of the structure of the DNA molecule, the role DNA plays and how it is wound into chromosomes within the nucleus for easy storage

#dna #genes #genetics

Active vs. Passive Transport: Compare and Contrast

BOGObiology 2018-01-17 | Comparison of the types of Active Transport and Passive Transport. This video covers diffusion, osmosis, facilitated diffusion, channel proteins, the sodium potassium pump, and both endocytosis and exocytosis.

00:00-00:29 Introduction
00:30-00:50 Dynamic Homeostasis
00:51-1:02 The Cell Membrane
1:03-1:52 Passive Transport: Diffusion and Concentration Gradients
1:52-2:33 Passive Transport: Facilitated Diffusion and Osmosis
2:33-3:01 Active Transport: ATP
3:02-3:39 Active Transport: Channel Proteins
3:39-4:21 Active Transport: Sodium Potassium Pump
4:21-5:40 Endocytosis and Exocytosis
5:40-6:02 Summary

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#activetransport #passivetransport #diffusion
[BOGObiology]. (2018, January 17). Active vs. Passive Transport [Video File]. Retrieved from youtu.be/Gecu_RKFPho

Cell Membrane Structure, Function, and The Fluid Mosaic Model

BOGObiology 2017-12-04 | Cell Membrane Guided Notes: etsy.me/34iZyb9
This video reviews the structure and function of the cell membrane. It needs to be selectively permeable; it uses cholesterol to maintain fluidity, and multiple channel proteins, carrier proteins, glycoproteins and peripheral proteins. This video also discusses, diffusion of certain particles, the sodium potassium pump, the role of glycoproteins in conception, and how peripheral proteins explain the mechanism of cyanide poisoning.

00:00-00:11 Introduction
00:11-00:26 Role of the Cell Membrane
00:26-00:40 Components of the Cell Membrane
00:40-1:12 Phospholipids in the Cell Membrane
1:12-1:57 Cholesterol in the Cell Membrane
1:57-2:42 Membrane Transport and Channel Proteins
2:42-3:06 Carrier Proteins and the Sodium Potassium Pump
3:06-3:45 Glycoproteins in the Cell Membrane
3:45-4:20 Peripheral Proteins in the Cell Membrane
4:21-5:07 The Fluid Mosaic Model

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[BOGObiology]. (2017, December 4). Cell Membrane: Fluid Mosaic Model and Semipermeability[Video File]. Retrieved from youtu.be/UxvFdW9aO0s

#cellmembrane #fluidmosaicmodel #phospholipid

Prokaryotes and Eukaryotes: Compare and Contrast!

BOGObiology 2017-11-08 | Prokaryotic and Eukaryotic organisms differ in size, genetic material and in the presence of membrane bound organelles.

But how is this relevant outside of biology class? The similarities and differences between prokaryotes and eukaryotes form a cornerstone of modern medicine, specifically regarding antibiotics! Antibiotics attach components of cells that are unique to prokaryotes, such as cell walls. This way, the prokaryotic bacteria are killed without damaging human eukaryotic cells.

0:00-0:13 Introduction
0:13-0:39 Examples of Prokaryotic and Eukaryotic Cells
0:39-1:03 Size of Prokaryotic and Eukaryotic Organisms
1:04-1:20 Presence of a Nucleus
1:20-2:07 Presence of Membrane-Bound Organelles
2:07-2:47 How Antibiotics Attack Prokaryotes/Bacteria
2:48-3:29 Beta Lactam Antibiotics: Penicillin
3:30-4:34 Macrolides Antibiotics: Erythromycin

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[BOGObiology]. (Year Posted, Date Posted). Prokaryotes, Eukaryotes and Antibiotics! [Video File]. Retrieved from youtu.be/WhwacqLrkW8

#prokaryotes #eukaryotes #antibiotics #superbug

Plant Cells vs. Animal Cells: Compare & Contrast!

BOGObiology 2017-11-01 | Plant and Animal Cells need to tackle many of the same problems in order to survive; maintaining homeostasis, protein synthesis, passing on genetic information, cell-to-cell communication... the list is long! But how do they do it? Which strategies are the same and which are different?

This animation shows you the function of plant and animal cells at a middle school and high school level, and discusses organelles such as the nucleus, nucleolus, endoplasmic reticulum, ribosomes, golgi apparatus, lysosomes, mitochondria, chloroplasts, centromeres and centrosomes

0:00-0:22 Introduction: Plant and Animal Cells and Organelles Compared
0:22-0:47 Maintenance of Internal Environment: Semi Permeable Membranes
0:47-1:05 Genetic Information: Nucleus and Nucleolus
1:05-1:23 Creating Proteins: Ribosomes, Rough ER, Smooth ER
1:23-1:53 Moving Items: Rough ER, Smooth ER
1:53-1:59 Similarities between Plant and Animal Cells
1:59-2:25 Storing Items: Vacuoles
2:25-2:56 Obtaining Energy: Photosynthesis and Respiration
2:56-3:18 Cell Division: Vesicles, Centrioles
3:18-3:47 Maintaining Cell Shape: Cell wall, Centrosomes, Cytoskeleton (minor role)
3:47-4:15 Removing Waste: Lysosomes, Proteases
4:15-4:37 Cell Communication: Plasmodesmata, Endocytosis, Exocytosis, Gap Junctions (and more)
4:37-5:26 Review and Summary

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[BOGObiology]. (Year Posted, Date Posted). Plant vs. Animal Cells. [Video File]. Retrieved from youtu.be/7iRRDcYKL-M

#plantcell #animalcell #biology

Photosynthesis vs. Cellular Respiration Comparison

BOGObiology 2017-10-26 | Photosynthesis vs Respiration Study Guide: etsy.me/347Vh75
This video compares and contrasts Photosynthesis and Cellular Respiration. It covers relevant organisms, reagents and products, location within the cell, chemiosmosis and the generation of ATP, and a review of the major steps (Light Dependent Reactions and the Light Independent Reactions/Calvin Cycle for Photosynthesis, and Glycolysis, Krebs Cycle and the Electron Transport Chain for Respiration).

Chapters:
0:00-0:12 Intro
0:13-0:37 What the AP Biology Curriculum has to say
0:38-1:00 Goal of Photosynthesis and Cellular Respiration
1:01-1:27 Organisms
1:29-3:00 Reagents, Products and Equations
3:03-4:47 Location of Photosynthesis and Cellular Respiration
4:48-5:34 Major Reaction Steps of Photosynthesis
5:35-6:49 Major Reaction Steps of Cellular Respiration
6:50-7:21 Summary

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[BOGObiology]. (2017, October 25). Photosynthesis vs. Cellular Respiration [Video File]. Retrieved from youtu.be/xmfhKbmQhq0

#photosynthesis #cellularrespiration #biology

NGSS: HS-LS1-7

Sex Linked Traits: Baldness and Hemophilia

BOGObiology 2017-10-18 | Sex Linked Traits: When genes on the X or Y chromosome code for particular traits, we call them sex-linked traits. This video reviews some common examples, such as male pattern baldness and hemophilia.

00:00-00:11 Introduction
00:11-00:34 Chromosome Counting
00:34-1:12 X and Y Sex Chromosomes
1:12-2:53 Sex Linked Recessive Trait: Hemophilia
2:53-3:15 Hemophilia Punnett Square
3:15-3:40 Royal Hemophilia Pedigree Chart
3:40-3:59 Summary

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[BOGObiology]. (2017, October 18). Sex Linked Traits: Royal Hemophilia. [Video File]. Retrieved from youtu.be/-6RGz1YM11o

#sexlinkedtraits #genes #genetics

Epigenetics: Nature vs. Nurture

BOGObiology 2017-10-11 | Epigenetics are heritable changes that occur without changes to the DNA sequence. Understanding it can help shed light on the Nature vs. Nurture debate.
00:00-00:21 Introduction
00:21-00:33 Traditional View of Genetics
00:34-1:28 Experiences Can Manipulate Gene Expression
1:29-2:15 Review of Gene Expression
2:16-3:02 Mechanisms of Epigenetics: DNA Methylation
3:03-4:12 Mechanisms of Epigenetics: Histone Modification
4:12-4:55 Epigenetics Examples: Agouti Mice & Obesity
4:55-6:09 Epigenetics Examples: Stress Response in Rats
6:09-6:33 Summary

Certain environmental conditions can change whether genes are activated or inactivated. These conditions can include drugs, chemicals and nutrition. Exposure can change the level of methylation, changing whether RNA polymerase can attach to the DNA molecule. The behavior of the histones can also be changed; the tightness of the DNA wrapping makes the genetic material either easier or more difficult to access, thereby changing the ease with which it is used. Check it out!

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[BOGObiology]. (2017, October 11). Epigenetics: Nature vs. Nurture. [Video File]. Retrieved from youtu.be/Q8BMP6HDIco

#genetics #epigenetics #naturevsnurture

Proteins and Nucleic Acids : Key Biomolecules II

BOGObiology 2017-10-02 | Proteins and Nucleic Acids are key biomolecules. Nucleic acids consist of alternating backbones of phosphate groups and ribose sugar, with nitrogen bases branching out from the sugar group. They contain a genetic "blueprint"; a code that cells use to create proteins.

Proteins are built from components called amino acids. Each of 20 amino acids has a unique R-group, which gives each component a unique make up. Amino acids are strung together using peptide bonds in a process called dehydration synthesis. Finally, the polypeptide is strategically folded in order to assume a useful shape.

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[BOGObiology]. (2017, October 2). 5 Minute Bio – Homeostasis. [Video File]. Retrieved from youtu.be/qwS18uTzRsE

#protein #nucleicacid #biology

Codominance and Incomplete Dominance: Non-Mendelian Genetics

BOGObiology 2017-09-26 | Some traits don't follow the rules of Mendelian Genetics! This tutorial explains the concepts of co-dominance and incomplete dominance; two common exceptions to traditional genetics.

Organisms that inherit traits via complete dominance will show the dominant trait in their phenotype. In this case, it would be a blue phenotype. Only one allele is dominant.

Organisms that inherit traits via co-dominance will display BOTH phenotypes; in this case yellow and blue polka dots. BOTH alleles are dominant. A real life example is cow coat color. A red cow crossed with a white cow will produce a calf that has red and white patches on its coat, a pattern called "roan".

Organisms that inherit traits via incomplete dominance will display a BLEND of phenotypes. In this case, the offspring would be green, a combination of blue and yellow. Neither allele is completely dominant. Real life examples include snapdragon flowers; a red flower crossed with a white flower will produce a pink flower.

00:00-00:21 Introduction
00:22-00:45 Punnet Squares Complete Dominance
00:45-00:56 Non Mendelian Genetics
00:56-1:41 Types of Dominance: Homozygous Dominant
1:41-1:51 Types of Dominance: Homozygous Dominant
1:51-2:38 Types of Dominance: Heterozygous
2:38-3:02 Codominance: Roan Cows & Blood Type
3:02-3:20 Incomplete Dominance: Flower Petals & Hair Texture
3:20-4:09 Definitions of Complete, Codominance and Incomplete Dominance

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[BOGObiology]. (2017, September 26). Codominance and Incomplete Dominance: Non-Mendelian Genetics. [Video File]. Retrieved from youtu.be/FXc5F9AMAiQ

#codominance #incompletedominance #genetics

Mendelian Genetics: The Dihybrid Cross

BOGObiology 2017-09-19 | Another key topic in Mendelian Genetics is the DiHybrid Cross; working on the probability that TWO traits will be inherited. This video tutorial covers gametes, alleles and several example crosses.
00:00- Introduction
0:14-0:32 Mendelian Genetics
0:32-1:02 Haploid Gametes, Diploid Offspring
1:03-1:57 Homozygous vs Heterozygous
1:57-2:44 Homozygous Dominant x Homozygous Recessive Punnet Square
2:44-3:50 DiHybrid Cross
3:50-4:07 Genotypes from Dihybrid Cross
4:07-4:32 Phenotypes from Dihybrid Cross
4:33-5:43 Practice Punnet Square

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[BOGObiology]. (2017, September 18). Mendelian Genetics: The Dihybrid Cross. [Video File]. Retrieved from youtube.com/watch?v=bkk__-2G2Zw&feature=youtu.be

#genetics #dihybridcross #punnetsquare

Mendelian Genetics: Genotypes, Phenotypes and Punnett Squares

BOGObiology 2017-09-12 | An overview of Mendelian Genetics!

Genetics can be complex; knowledge of genotypes and phenotypes allow us to predict the probability of offspring displaying certain characteristics or traits. Dominant and recessive traits are passed from parent to offspring in the form of alleles; each offspring receives one allele from each parent. The offspring may be homozygous or heterozygous for a given trait.

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[BOGObiology]. (2017, September 11). Mendelian Genetics. [Video File]. Retrieved from youtu.be/_478UemZ-2E

#genetics #genotype #phenotype #hybrid

Vittle and Screencasting Tips and Tricks

BOGObiology 2017-06-06 | Here's the stylus that I use. amazon.com/gp/product/B0052WESJ0/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=lboghossian-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B0052WESJ0&linkId=b22ee2c78a689271e2d35c3e360c072e

This video is about Vittle Best Practices while using the flipped classroom approach. In it I show how I:

1) Create detailed drawings with a stylus
2) Make items appear on the screen power-point style
3) Use the lock screen
4) Select certain colors
5) App-smash

I hope you find it useful in creating your own screencasts!

#screencast #flippedlearning #elearning

The Cell Cycle: Interphase, Mitosis and Division Checkpoints!

BOGObiology 2017-02-15 | The Cell Cycle is a series of events spanning the cell's entire lifespan. In interphase, the cell grows during G1, completes DNA synthesis during the S Phase, creates necessary organelles for cell division and grows more in G2, and thoroughly scans its DNA for errors (twice!) If necessary, it can also enter a quiescent stage called G0. Then, the cell enters the "M-Phase" and undergoes mitosis, where it passes through a final checkpoint before splitting into two new daughter cells! Awesome!

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[BOGObiology]. (2017, February 15). 5 Minute Bio – The Cell Cycle. [Video File]. Retrieved from youtu.be/G1sJ3GJc_ys

Cellular Respiration Overview: Why Exercise Doesnt Make You Drunk!

BOGObiology 2017-01-30 | NEW VERSION OF THIS VIDEO! youtu.be/2_ceHsFmLVk

An overview of Aerobic and Anaerobic Cellular Respiration, its reagents and products, its similarities to photosynthesis and the major steps involved. We introduce Glycolysis, the Kreb's Cycle, Electron Transport Chain as well as both Lactic Acid Fermentation and Alcoholic Fermentation.

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[BOGObiology]. (2017, January 30). Cellular Respiration Overview. [Video File]. Retrieved from youtu.be/Vh7vg7zG3cQ

Easy How to Use the Flipped Classroom Teaching Method!

BOGObiology 2017-01-04 | I started flipping my classroom a few years ago after seeing some of my amazing colleagues tinkering with the approach. I love how much more time it gives me to do more project based learning, inquiry and differentiation during the class day! This student-centered approach is also more engaging for the students AND more fun for me, the teacher.

Below are the steps I use when I flip a lesson:
1) Decide which content to flip
2) Create or select an appropriate video
3) Decide where to place it in the unit and assign the video
4) Check for understanding
5) Engage in an interesting follow up activity

Please leave a comment and share your favorite way of flipping the classroom and/or your most effective student-centered activities!

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[BOGObiology]. (2017, January 4). Easy How to Use the Flipped Classroom Teaching Method!. [Video File]. Retrieved from youtu.be/eplhNzbjeMk

Welcome to BOGObiology!

BOGObiology 2016-12-12 | Welcome to BOGObiology! This channel covers a wide range of topics; everything from the macro to the micro. Outside of Youtube, I'm a teacher. I get to test drive new ideas in the classroom and I know where students tend to get stuck. I believe in combining key scientific information with humor in order to make learning relevant, fun and engaging! Every cartoon character you see in the videos was suggested by my students. Even with their constant requests to light things on fire or blow things up (...in the name of science!) I stil think I have the best job in the world. I try to make videos that are both helpful and relevant, and I'm always looking for new material. I hope you'll leave suggestions for scientific topics or cartoon characters in the comments section! Thanks for watching and don't forget to subscribe!

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[BOGObiology]. (2016, December 12). Channel Trailer [Video File]. Retrieved from youtu.be/ZHmJPCJ6b7Y

Homeostasis and Negative Feedback Loops

BOGObiology 2016-12-03 | This video covers homeostasis; the dynamic equilibrium that organisms work to maintain in order to survive. Two examples of homeostasis in the human body are body temperature and blood glucose, both of which are essential for survival. Featuring the Simpsons, this video also covers negative feedback loops as well as the basics of passive and active transport.

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[BOGObiology]. (2016, December 3. 5 Minute Bio – Homeostasis. [Video File]. Retrieved from youtu.be/kAy-03hIfck

NGSS and AP Standards: (AP LO 2.12; HS-LS 1-3)

Neurons & The Synapse Overview

BOGObiology 2016-07-11 | Introduction to the basics of the synapse. This video covers the transmission of an impulse from the dendrites, down the axon via the myelin sheath, transformation into a chemical signal which crosses the synaptic cleft. We will also review excitatory and inhibitory neurotransmitters and their connection to depression, anxiety and addiction.

[BOGObiology]. (2016, July 11). The Synapse. [Video File]. Retrieved from youtu.be/TMynEhTli-Y

Fish Respiration

BOGObiology 2016-05-02 | Comparison of respiration and ventilation in humans and fish. This is an overview of the various gas exchange structures; alveoli, bronchi, trachea, lamellae, gill filaments and gill arches.

Sexual vs. Asexual Reproduction

BOGObiology 2016-05-01 | Sexual vs Asexual Reproduction. What are the costs and benefits of each reproductive strategy? This video reviews the idea of meiosis vs. mitosis, sperm and egg cells and sex determination.

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[BOGObiology]. (2016, May 1). Reproduction 3: Sexual vs. Asexual Reproduction. [Video File]. Retrieved from youtu.be/r1SeoVfw7Tc

Marine Nutrient Cycle and Energy Flow

BOGObiology 2016-04-13 | This video covers the topics of nutrient cycling and energy flow in marine ecosystems. We discuss the concepts of producers, consumers and decomposers as well as the "10% Rule". This rule states that approximately 10% of the caloric energy content is passed to the next "step" in the food chain. Additionally, about 10% as many organisms exist at each level compared to the level immediately below it. Enjoy and thanks for stopping by!

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[BOGObiology]. (2016, April 12). Marine Nutrient Cycling and Energy Flow. [Video File]. Retrieved from youtu.be/G1yPrfDaijE

Proteins and Nucleic Acids

BOGObiology 2016-02-07 | UPDATED VERSION AVAILABLE! youtube.com/watch?v=qwS18uTzRsE

An overview of the biomolecules proteins and nucleic acids. This video covers their structure, function and purpose in biology. Proteins are composed of linked amino acids, then folded into a specific shape. They play many roles in the body, and each protein's shape is specifically designed to fit that role. Nucleic acids are responsible for the organism's genetic material, and are composed of nitrogen bases, phosphates and sugars. These long strings may be single or double stranded. Thanks for watching!

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[BOGObiology]. (2016, February 7). Biomolecules 2: Proteins and Nucleic Acids. [Video File]. Retrieved from youtu.be/COyTQmNIeAM

The Octet Rule, Ionic Bonding, Covalent Bonding & The Periodic Table

BOGObiology 2016-02-07 | An overview of some major concepts from chemistry that are especially important in biology. This video covers how to read and interpret the Periodic Table, Subatomic Particles (electrons, neutrons and protons), The Octet Rule, and Covalent Bonding vs. Ionic Bonding.

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[BOGObiology]. (2016, February 7). The Octet Rule, Ionic Bonding, Covalent Bonding & The Periodic Table. [Video File]. Retrieved from youtu.be/IyAb4lKBMnQ

Carbohydrates and Lipids: Key Biomolecules I

BOGObiology 2016-02-07 | An overview of carbohydrates and lipids, two biomolecules that are essential in biology. Watch for information on the structure, function and examples of each type of molecule. This video includes information on monosaccarides, disaccarides and polysaccarides

How C3, C4 and CAM Plants Do Photosynthesis (Old version!)

BOGObiology 2016-02-05 | Updated version of this video! youtu.be/P_JU9vYd5O0

A comparison of C3, C4 and CAM plants. Plants have different systems for harvesting energy depending on their environment. A sugar maple tree in New England faces very different challenges in temperature and humidity than does a cactus in the Mojave Desert! Note the strategies used by desert plants in order to effectively preserve their water in an arid environment, and to perform Carbon Fixation!

Thanks to the viewer who pointed out that PEP is "Phosphoenolpyruvate." Apologies for the mis-speak!

00:00-00:18 Introduction
00:18-4:08 Carbon Fixation and the Calvin Cycle
4:08-4:38 C3 Plant Internal Leaf Structure
4:38-5:36 C4 Plant Internal Leaf Structure
5:36-9:59 C4 Plant Carbon Fixation
9:59-11:53 CAM Plant Carbon Fixation
11:54-12:15 Summary
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[BOGObiology]. (2016, February 5). Photosynthesis 5 Light Independent Reactions. [Video File]. Retrieved from youtu.be/HbLg4lMpUa8

Screencasting 101: How I Make Screencasts Using Vittle App

BOGObiology 2015-12-31 | I put together a screencast about making screencasts using the iPad app called "Vittle" for a professional development seminar last year. I've tried a number of whiteboard apps, and Vittle is my personal favorite by far. It's very intuitive and has many features that I like, such as the option to delete segments, create an unlimited color palette, and select and move objects around the screen. Vittle is very intuitive, but several folks still found this tutorial helpful as they were trying to make their own screencasts for the first time. I love making screencasts for my students because it allows for content delivery at a student's own pace, and they can listen, take notes and rewind it as many times as they want. This enables many different kinds of learners to access the content in their own way in an environment that is comfortable for them, leaving class time free to solve problems, try experiments and do research which they would normally have to do independently. Happy screencasting and please let me know if you have further questions!

Energy Flow and Nutrient Cycling

BOGObiology 2015-09-09 | This video covers the topics of energy flow and nutrient cycling in ecosystems. It reviews primary, secondary and tertiary consumers, producers and decomposers. Additionally, this video covers the 10% rule; the idea that 10% of the energy or calories are transferred "up" each trophic level. Enjoy!

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[BOGObiology]. (2016, September 9). Energy Flow and Nutrient Cycling. [Video File]. Retrieved from youtu.be/urmKLXwv_50

Leaf Cross-Section (Old version!)

BOGObiology 2015-06-19 | New version of this video: youtu.be/_y-HCi7mJjM

This is a description of a leaf cross section at the cellular level. Leaves contain a number of different tissues and cell types arranged in a particular way. From the top down, these tissues are the Waxy Cuticle, Upper Epidermis, Palisade Mesophyll, Spongy Mesophyll, Bundle Sheath Cells, Vascular Bundle, Lower Epidermis and Waxy Cuticle. The Waxy cuticle would ordinarily provide an air tight seal, but there are openings within it called the stomata, which open and close strategically to take in gasses but minimize water loss.

This leaf is from a standard C3 plant (ie a non-desert plant) but there are specific modifications in desert plants that are quite interesting. Check out youtube.com/watch?v=HbLg4lMpUa8&t=206s for more details!

00:00-00:18 Introduction and Orientation
00:18-00:40 Waxy Cuticle
00:40-1:01 Upper Epidermis
1:01-1:46 Palisade Mesophyll
1:46-2:25 Spongy Mesophyll
2:26-4:04 Vascular Bundle (Bundle Sheath Cells, Xylem, Phloem)
4:05-4:21 Lower Epidermis
4:21-4:30 Waxy Cuticle
4:30-6:03 Stomata, Guard Cells and Gas Exchange
6:04-7:50 Leaf Microscopy

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[BOGObiology]. (2015, June 19). Photosynthesis 2 Leaf Cross Section. [Video File]. Retrieved from youtube.com/watch?v=Q8mphPjPnlU&t=1s

ATP in Photosynthesis

BOGObiology 2015-06-19 | This is an introduction to the concept of ATP, a key molecule in many areas of biology. Here, we liken ATP to a rechargeable energy currency. ATP is the currency used by cells, but it is not the energy we get from food. Food energy cannot be directly used to power cells; instead it is broken down and that energy is harnessed to recharge "spent" ATP molecules.

ATP is recharged in a cycle. It's high energy form is called ATP and stores energy within its bonds. After the molecule has had some of the bonds broken, it releases energy and becomes its low energy form called ADP. ADP can be "recharged" through the process of cellular respiration for later use.

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Avoid plagiarism! Cite BOGObiology!

[BOGObiology]. (2015, June 19). Photosynthesis 1 ATP Introduction. [Video File]. Retrieved from youtube.com/watch?v=bSycFsWyxbM