7.10

Question 1

Give the role of each of these features in a muscle fibre:
a) sarcoplasmic reticulum
b) myoglobin
c) mitochondria
d) glycogen

Answer 1

a) controls the calcium concentration in the muscle
b) binds to oxygen to provide an emergency store
c) site of respiration, to provide ATP for muscle contraction
d) storage molecule of glucose, ready to be broken down for glycolysis

Question 2

State the main type of respiration that takes place in:
a) fast twitch fibres
b) slow twitch fibres

Answer 2

a) anaerobic respiration
b) aerobic respiration

Question 3

Explain how slow twitch fibres are adapted to their role

Answer 3

High in myoglobin, to have lots of oxygen availability for aerobic respiration
High mitochondria and blood density concentration for lots of respiration + oxygen supply

Question 4

Explain how fast twitch fibres are adapted to their role

Answer 4

High glycogen and phosphocreatine stores for anaerobic respiration
Low in myoglobin, as less oxygen needed
Low density of mitochondria and blood vessels as oxygen not needed