Muscle Fibres

Question 1

Fast muscle fibres

Answer 1

-contract rapidly
-myosin heads bind and unbind from the actin binding sites 5x faster than slow muscle fibres
-rely on anaerobic respiration for ATP supply
-found in predators to catch prey of high speeds

Question 2

Slow muscle fibres

Answer 2

-contract more slow and suited to sustained activities such as waiting and perching
-rely on aerobic respiration for ATP
-used for slower activities eg stalking prey or migration

Question 3

How do they help to contract muscles?

Answer 3

Slow twitch use muscles fairly, evenly to help contraction last longer, whereas fast twitch help make contractions faster and more powerful