B6-056 Muscle Contraction

Question 1

smallest unit of contraction in the muscle

Answer 1

sarcomere

Question 2

what two proteins make up the striated pattern of muscle?

Answer 2

actin (lighter)
myosin (darker)

Question 3

[…] on either side of the sarcomere holds the actin protein in a structured form

Answer 3

z lines

Question 4

what protein makes up the I band?

Answer 4

actin

Question 5

what protein makes up the H band?

Answer 5

myosin

Question 6

I band is connected to the

Answer 6

Z line

Question 7

what protein makes up the A band?

Answer 7

actin and myosin

Question 8

contains ATP and actin binding sites

Answer 8

myosin head

Question 9

protein responsible for turning on muscle contraction

Answer 9

troponin

Question 10

binds troponin to tropomyosin

Answer 10

Tn-T

Question 11

binds calcium during contraction

Answer 11

Tn-C

Question 12

inhibitory protein on tropomyosin when there is no Ca++

Answer 12

Tn-I

Question 13

actin and myosin interacting to generate force is known as the

Answer 13

cross bridge

Question 14

steps of the cross bridge cycle

Answer 14

1) ATP hydrolysis
2) Calcium binding troponin C
3) actin-myosin bind
4) working stroke occurs
5) sliding filament
5) new ATP comes in to release actin and myosin

Question 15

you have to have […] to release the actin-myosin binding

Answer 15

new ATP

Question 16

action potential is spread down […] to allow muscle fibers to move in concert

Answer 16

t tubules

Question 17

action potential moving down the t tubules triggers […] release from inside muscle

Answer 17

Ca++

Question 18

contraction will continue to occur as long as […] is present

Answer 18

calcium

**there is a system that reuptakes the calcium in order to keep intracellular calcium low

Question 19

what bands change in length as the sarcomere contracts?

Answer 19

H and I shorten

Question 20

[…] facilitates the release of actin from myosin

Answer 20

ATP

Question 21

what causes rigor mortis?

Answer 21

lack of ATP for release of actin from myosin

Question 22

maximal tension is generated when sarcomere length is

Answer 22

optimal

**if given a graph, optimal region is where plateau is seen

Question 23

force generation […] as sarcomere length […]

Answer 23

increases
decreases

Question 24

force generated by a muscle is a function of its […]

Answer 24

velocity

Question 25

the rate that cross bridges form between actin and myosin is referred to as

Answer 25

rate of constants

Question 26

force generated by a muscle depends on the number of [...] attached

Answer 26

cross bridges

Question 27

because the rate of constant attachment doesn't change, as filaments slide past each other faster, force [...]

Answer 27

decreases **less cross bridges attach

Question 28

as filament velocity decreases more cross bridges attach generating [...]

Answer 28

greater force

Question 29

prolonged eccentric muscle contractions cause

Answer 29

disorganization of myofibrillar proteins around the Z disk

Question 30

CK levels demonstrated a delayed increase following [...] contraction

Answer 30

eccentric

Question 31

proteins on the thin filament [3]

Answer 31

actin troponin tropomyosin

Question 32

anchoring proteins that help maintain the length of thick and thin filaments

Answer 32

titin (thick) nebulin (thin)

Question 33

type 1 fibers have [more/less] mitochondria than type II

Answer 33

more

Question 34

what type of fibers primarily utilize aerobic respiration

Answer 34

type I

Question 35

what type of fibers have a slow contraction speed?

Answer 35

type I

Question 36

type I fibers generate [more/less] power than type II

Answer 36

less

Question 37

what type of fiber primarily uses anaerobic respiration?

Answer 37

type II

Question 38

what type of fiber fatigues more easily?

Answer 38

type II

Question 39

what type of fibers are fast?

Answer 39

type II

Question 40

what type of fibers are slow?

Answer 40

type I

Question 41

what type of fiber uses oxidative phosphorylation to produce a sustained contraction?

Answer 41

type I

Question 42

what type of training produces type I fibers?

Answer 42

endurance training

Question 43

what type of training produces type II fibers?

Answer 43

resistance training, sprinting