KN 152 exam 1

Excitation-Contraction Coupling sequence

1. action potential is propagated along sarcolemma and down tubules. 2. action potential triggers calcium release from terminal cisternae or sarcoplasmic reticulum. 3. Calcium binds to troponin c, troponin changes shape, removing the blocking action of tropomyosin, actin active sites exposed. 4. contraction 5. removal of calcium by reuptake into the sarcoplasmic reticulum after the action potential ends. 6. tropomyosin blockage restores, contraction ends and muscle fiber relaxes.

What do they recommend as part of the prescription?

30 min exercise 5days/week. 5-7 servings of fruit and veggies, involve the family, have fun!

What group started Exercise Is Medicine?

AMA and ACSM

Why is ATP important for contraction?

ATP binds myosin, moving the myosin to its high energy state. ATP can attach to myosin which allows the cross bridge cycle to start again. further muscle contraction can occur.

24. Advantages/Disadvantages of fats vs. carbs

Advantages of carbs: Faster aerobic ATP production than fat breakdown. CHO is the predominant fuel of the CNS. Disadvantages of carbs: Stores are limited. Energy density is low. Advantages of fats: Stores are huge. Storage form has high energy density. Disadvantages of fats: Slower aerobic ATP production than CHO breakdown (~35% slower than CHO)

15. Where does anaerobic and aerobic metabolism occur in the cell - cytoplasm vs. mitochondria? (be familiar with the table adapted from Brooks & Fahey—that's sprinkled throughout the Metabolism lecture).

Anaerobic occurs in the cytoplasm and aerobic occurs in the mitochondria

12. Understand anaerobic and aerobic )(e.g. fast and slow) glycolysis

Anaerobic: The transformation of glucose to lactate when limited amounts of oxygen are available. Only an effective means of energy production during short, intense exercise, providing energy for a period Ranging from 10 seconds to 2 minutes. Aerobic: The conversion of glucose to lactate in the presence of oxygen

11. Be able to apply energy system knowledge by knowing which system would be used for physical activities such as sprinting, etc.

Anaerobic: sprinting, weightlifting Aerobic: walking, swimming, cycling

22. Cross-over concept (intensity dependent)

As the intensity and duration of the exercise increases, fats are used more and more but carbs are still essential and play an important role.

What is metabolism?

Chemical that utilizes energy and result in anabolism (build up of cell components) and catabolism (breakdown of substrates to release energy)

17. Know which fuel is used when (fat, carbohydrate, protein, etc.) during exercise.

Fat and carbohydrates are used during. Protein is used for recovery after

20. #s of ATP made by one reaction in an immediate energy system, one molecule of glucose in anaerobic and aerobic glycolysis, and an example of the # ATPs made by one long-chain fatty acid in beta oxidation (e.g. fat metabolism).

Glycolysis: 4 ATP Beta oxidation: 129 ATP

Know and understand the three main ways (e.g energy systems) that ATP is generated

Immediate (PC), non-oxidative (anaerobic glycolysis), oxidative phosphorylation (aerobic)

Also know how they are interrelated in terms of which system is activated first in which system has the largest capacity (i.e the ability to generate the most ATP)

Immediate activates first. Glycolysis makes 2 to 4 ATP and oxidative phosphorylation makes 38 ATP. Krebs cycle and electron transport chain generates the most ATP of 36 to 38

14. How is glucose and fat stored in the body?

Insulin. Insulin turns extra food into larger packages of glucose called glycogen. Glycogen is stored in the liver and muscles. Insulin also helps our body store fat and protein.

Understand ATP in terms of its function in the body

Main energy source for metabolic functions

Force-velocity relationship

Max velocity at lowest resistance

What types of biological work require ATP in the body?

Mechanical chemical and transport

Organization of muscle: Muscle, fascicles, fibers, etc...

Myofibrils are organelles within the muscle cell that contain thick and thin myofilaments. Myofilaments are organized into sacromeres

what are Potential energy sources available from Krebs cycle

NADH, FADH2, and ATP

19. What factors contribute to EPOC.

Restoration of blood and oxygen stores, lactate removal, elevated hormones, elevated body temperature.

8. Basic premise of electron transport chain (e.g. proton gradient) and how many ATPs are made here per NADH/FADH.

Result in formation of H20 and ATP

13. Why is fat more efficient at producing energy than carbohydrate?

The amount of oxidation that takes place as these compounds are converted to carbon dioxide and water. Fats require more oxidation to become CO2 and H2O than carbohydrates

Why is oxygen important?

The production of energy in the body depends on oxygen. Also oxygen combines with metabolic waste products to allow their elimination from the body (oxidation reduction cycle)

16. Why are NADH and FADH important? Where do they go to make energy?

They are affixed with electrons and are transferred to the intter membrane of the mitochondria. They travel down the ETC, releasing electrons they once had. The end result is loads of energy. (34 ATP)

What are the primary goals?

To make physical activity assessment and exercise prescription a standard part of the disease prevention and treatment paradigm for all patients.

Characteristics of fiber types (fast/slow)

Type one (slow twitch fibers), type two A (fast oxidative fibers), type two B (fast glycolytic fibers).

9. The basic workings of beta oxidation—and why beta oxidation yields so many ATPs.

breakdown of saturated fatty acids to aid in energy production. ATP attaches to fatty acid chain which then becomes acyl-coA. Acyl-coA taken in to mitochondrial matrix where it loses two carbons and acetyl coA is produced.

Why is Calcium important for contraction?

calcium ions flow into cytoplasm and bind troponin and allows troponin to change shape and expose the actin-myosin binding site.

Job of neuromuscular junction

chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction.

Type of muscle contraction

concentric contraction causes muscles to shorten thereby generating force, eccentric contractions cause muscles to elongate in response to a greater opposing force.

23. Prolonged exercise—fuel preferences?

fats

18. Understand why the O2 deficit and EPOC occur. Do trained individuals have a different response?

increased amount of oxygen is necessary to convert lactic acid back to pyruvate acid. Fuel the body's increased metabolism from the increase in body temperature which occurs during exercise. Increased rate of oxygen intake following strenuous activity intended to erase the body's "oxygen deficit"

Length-tension relationship (greatest force is developed when there is maximal cross-bridge interaction)

isometric tension generation in skeletal muscle is a function of the magnitude of overlap between actin and myosin filaments.

10. Protein usage for energy production—the primary take home on this.

protein is used to build, maintain, and repair body tissues, as well as to synthesize important enzymes and hormones

21. Lactate buffering

resists changes in pH. Buffered by bicarbonate. increases in lactic acid accompanied by decreases in bicarbonate and blood pH.

Sarcomere

structural unit of myofibril in striated muscle.

What overall factors contribute to the top causes of death today v. 100 years ago?

today: Inactivity - 100 years ago: influenza, pneumonia

Why is acetyl CoA important?

universal and common intermidate. It's main function is to convey the carbon atoms within the acetyl group to the citric acid cycle to be oxidized energy production.