Chapter 12 (Part 5)

Question 1

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

glycolytic enzyme content

Answer 1

slow is low, fast is high

Question 2

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

mitochondria numbers

Answer 2

slow is high because it’s using oxidative phosphorylation ; fewer in fast

Question 3

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

capillary density

Answer 3

slow is high because it needs oxygen for longer + ox phos

Question 4

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

myoglobin

Answer 4

slow is high because it needs oxygen for longer + ox phos

Question 5

what is myoglobin?

Answer 5

oxygen-binding molecule in muscle

Question 6

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

glycogen

Answer 6

high in fast because it’s using glycolysis

Question 7

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

phosphocreatine

Answer 7

fast because it rapidly regenerates ATP to rapidly burn but you can’t generate a lot of it, gonna burn up in a few seconds

Question 8

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

sarcoplasmic reticulum

Answer 8

fst because they want to use lots of calcium to get max force

Question 9

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

fiber diameter

Answer 9

slow needs low cross bridge, so fewer sarcomeres. more sarcomeres means more actin and myosin which means larger diameter.

Question 10

what makes up sarcomeres?

Answer 10

actin and myosin

Question 11

why do you want lots of calcium in fast twitch?

Answer 11

you want force and the way you get max force is to get the max number of cross-bridge cyclings at the same time which you get from the calcium concentration

Question 12

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

myosin fiber ATPases

Answer 12

on the myosin head, hydrolyzes ATP to help do power stroke. higher in fast twitch, higher catalytic activity to hydrolyze ATP to cycle calcium out faster. starts the crossbridge.

Question 13

what are the properties (high or low) of slow twitch oxidative type I muscle fibers versus fast twitch glycolytic type II muscle fibers with respect to:

Ca+2 ATPase pumps

Answer 13

put calcium back in SR to start another cycle higher for fast. STOPS crossbridge. higher in the sprinter.