Muscle Contraction

Question 1

What interaction do muscles contract through ?

Answer 1

They contract through two key proteins called actin and myosin, they use atp as an energy source.

Question 2

How many stages to muscular contraction are there?

Answer 2

4

Question 3

What happens in the first stage of muscular contraction?

Answer 3

Part of the myosin molecule attaches to the binding site on the actin filament; a cross bridge is formed.

Question 4

What happens in the second stage of muscular contraction ?

Answer 4

The myosin molecule bends, pulling actin filament along, adp and p are released- the power stroke.

Question 5

What happens in the third stage of muscular contraction ?

Answer 5

The attachment of a new atp molecule to the myosin head breaks the cros-bridge.

Question 6

What happens in the fourth stage of muscle contraction?

Answer 6

The head group moves back to its original confirmation as atp is hydrolysed to adp and p so another cross bridge can be formed.