Test 2 Flashcards
What are the three types of proteins in sarcomeres that needed for contraction?
Contractile, structural, and regulatory.
What does the contractile protein do?
Actin and myosin - regulates muscle contractions.
What do structural proteins do?
Titin, neublin, and desmin- titin and neublin stabilize sarcomere and hold myofibrils together.
What do regulatory proteins do?
Troponin and tropomyosin - regulate muscle contractions.
What are the two types of muscle fiber types?
Red (oxidative and slow - wild ducks) and white (glycolytic and fast - domesticated chickens).
Can fiber types change? If so, why?
Yes, exercise can change the fiber amount and how the muscle moves can too.
The muscle metabolism for glycolytic/anaerobic does what?
Produces ATP and lactic acid, does not require oxygen, and has a fast metabolism.
The muscle metabolism for oxidative/aerobic does what?
Metabolizes lactic acid to produce ATP (through TCA cycle and electron transport chain) and requires oxygen from the circulatory system.
Where is actin located and what does it do?
Located in the thin filament and contains binding site for myosin.
Where is myosin located and what does it do?
Primary protein located in the thick filament and binds to actin to cause a contraction.
Where is troponin located and what does it do?
Located in the thin filament where it binds calcium and makes tropomyosin.
Where is tropomyosin located and what does it do?
Located in the thin filament and blocks myosin binding site on actin.
Where is titin located and what does it do?
Runs from the z-disk to the m-line and stabilizes the structure of the sarcomeres.
Where is the neublin located and what does it do?
Runs the length of the thin filament and stabilizes that structure.
What are the connective tissues layers?
Muscle, muscle bundles, and muscle fibers.
What does muscle structure impact?
Tenderness
What is epimysium?
Connective tissue (muscle) and is first.
What is perimysium?
Connective tissue (muscle bundles) and is second.
What is endomysium?
Connective tissue (muscle fibers) and is third.
Sarcomeres can ________.
Dictate length
What are the two things needed for muscle contraction?
Need energy (ATP) and calcium.
What does ATP come from for muscle contraction?
Glycolysis, TCA cycle, and electron transport chain.
Where is calcium stored for muscle contraction?
Stored in sarcoplasmic reticulum and the SR is located “outside” the myofibril/sarcomere.
What’s the conversion of muscle to meat?
Function of the muscle does not stop at death, during and after slaughter the body is trying to maintain homeostasis, and time.
__________ -> _________ -> _________ -> __________
Muscle, muscle bundles, muscle fibers, myofibrils
What is the contraction process?
- Calcium released by sarcoplasmic reticulum.
- Calcium binds to troponin, where troponin moves tropomyosin out of the myosin binding site on actin.
- Myosin binds to actin.
- ATP used by myosin head to create the “power stroke,” ATP -> ADP +Pi, and myosin head moves.
- SR pulls calcium out of the muscle cell.
- Actin/myosin bond is broken by ATP.
- Troponin and tropomyosin return to original confirmation.
