Muscle contraction

Question 1

Depolarization along the muscle down

where and does what?

Answer 1

T tubule,
this depolarizes the voltage-sensitive dihyropyridine receptor, which is mechanically coupled to ryanodine receptor, causing Ca2+ release

Question 2

Ca2+ does what

Answer 2

Bind to troponin C (C=Ca2+ binding)

Moves tropomyosin out of the mysoin-binding groove on actin filaments

Question 3

Pi releasing does what

Answer 3

power stroke

Question 4

ATP binding does what

Answer 4

Release from actin

Hydrolysis leads to cocked state

Question 5

Contraction shortens

Answer 5

H and I band between Z line (HIZ shrinkage)

A band remains the same length
A band is always the same length, myosin bundle

Question 6

Type I muscle

Answer 6

Slow twitch: red fibers resulting from
increase mito and myoglobin concentration
increased oxphos

Sustained contraction

Question 7

Type II muscle

Answer 7

Fast twitch, white fibers resulting from
decreased mito and myoglobin
increased anaerobic glycolysis

Weight training results in hypertrophy of this