Bio 28: Nutrition Instructor: Paul Nagami Laney College Jan. 28, 2014 Carbohydrates, pt. 1.
Real-World Applications of Cell Function Bio 10: Intro to Biology Instructor: Paul Nagami Laney...
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Transcript of Real-World Applications of Cell Function Bio 10: Intro to Biology Instructor: Paul Nagami Laney...
Real-World Applications of Cell Function
Bio 10: Intro to BiologyInstructor: Paul Nagami
Laney College
September 25, 2013
Agenda• Administrative Stuff• Exercise and Respiration• Aerobic and Anaerobic Exercise• Respiration vs. Fermentation (Review)• Fast and Slow Twitch Muscle
• Free Radicals and Antioxidants• The Need to Exercise Consistently
• Seven Deaths in Chicago (adapted from a case study by Michaela Gadzik)
• Wrap-Up
Aerobic vs. Anaerobic Exercise
Take a guess: On your index card, write down what you think the difference between aerobic and anaerobic exercise is.
Oxygen Use and ExerciseAerobic exercise:• Sustained exercise• Trains endurance (cardiovascular system)• Relies mostly on respiration using oxygen.Anaerobic exercise:
• Short, intense exertion• Trains muscle strength• Relies on respiration and lactic acid fermentation.
Sept. 20, 2013
O2
O2O2
AerobicAnaerobic
Fermentation
If O2 runs low, muscles do fermentation to get rid of extra NADH and pyruvic
acid.
Citric Acid Cycle
The Electron Transport Chain: A Molecular “Waterwheel”
Lactic Acid Fermentation: A Source of “Muscle Burn”
Fermentation turns pyruvic acid into lactic acid and recycles NADH.
Make a Prediction
Which of these two activities would have a faster, stronger effect on the pH of muscle tissue? Why do you think so?
Muscle Fatigue and Fermentation
Fast Twitch vs. Slow Twitch Muscle Fibers
Skeletal muscle fibers can be fast twitch or slow twitch fibers.
Slow twitch fibers use a lot of oxygen.• Lots of blood vessels for sustained contraction!Fast twitch fibers are specialized for quick, strenuous action.• Fewer blood vessels
On your index card:Which of these muscle
fiber types would do aerobic respiration?
Which type would you expect to find in leg
muscles that support standing up?
Dark and White Meat = Different Muscle Fibers!
White meat = fast twitch, anaerobicChicken breast = muscles that don’t need as much oxygen
Dark meat = slow twitch, aerobic
Chicken legs/thighs = muscles that need lots of oxygen
Oxidative Damage and Free Radicals
AntioxidantsInhibit reduction and oxidation reactions.May reduce formation of free radicals and reduce damage.But regular exercise also produces antioxidants!
Why might doing heavy aerobic exercise only once a week be unhealthy?
Deaths in the Chicago AreaCase 1 (September 29th, 1982):The night before, a twelve-year-old girl had a
stuffy nose and sore throat. Her parents gave her an extra-strength Tylenol and sent her to bed. The next morning, she was found collapsed on the floor of the bathroom.Case 2 (September 29th,
1982):A twenty-seven-year-old postal worker was found unconscious on the floor of his kitchen. He died within two hours.
Cases 3 and 4 (September 29th, 1982):Two relatives of the second victim died while preparing for
his funeral at his house. Before the patients collapsed, they felt dizzy and confused, suffering from headache and shortness of breath. They died within two hours.
More deaths in the Chicago area followed rapidly.
What Do We Know? What Do We Need to Know?
Autopsy Results
Some Possible Data from Cells
Molecule
Average level in
patients’ cells
Normal levels
Glucose 99 uM 100 uM
Pyruvate 27 uM 25 uM
NAD+ 10 uM 75 uM
NADH 400 uM 50 uM
What was affected? Was it glycolysis, the citric acid cycle, or the electron transport chain?
Conclusions