Muscles

Question 1

What are the features of Slow Twitch Muscle Fibres?

Answer 1

• Contract slowly
• Can keep going for a long period of
  time
• Red in colour as they contain many blood vessels
• Require more oxygenated blood
• High density of mitochondria for aerobic respiration

Question 2

What are the features of Fast Twitch Muscle Fibres?

Answer 2

• Contract rapidly
• Fatigue quickly as they consume a lot of energy
• Lighter in colour as lower density of capillaries
• Don’t rely on oxygen
• Use Anaerobic Respiration
• Low density of mitochondria

Question 3

What are the two proteins which make muscles contract?

Answer 3

Actin and Myosin

Question 4

What is the Sliding Filament Theory of Muscle Contraction?

Answer 4

When ATP is hydrolysed (water added) during muscle contraction

Question 5

How do muscles contract?

Answer 5

• A nerve impulse sent from brain to muscle, through neurons
• myosin head attaches to binding site on actin filament, creates cross bridge. uses ADP
• Head group bends, pulling actin filament along
• ATP molecule attaches to myosin head, breaks the cross bridge
• Head group moves back to original position to relax muscle