Types Of Muscle Fibre

Question 1

Slow - Twitch Fibres: What function do they perform?

Answer 1

> Contract slowly and provide less powerful contractions but over a longer period

> Adapted for endurance e.g. running a marathon

Question 2

Slow - Twitch Fibres: Where are they found in humans?

Answer 2

> Most common in muscles such as the calf muscle, which must contract constantly to maintain the body in an upright position

Question 3

Slow - Twitch Fibres: How are they suited to their role?

Answer 3

> Adapted for aerobic respiration to avoid a build up of lactic acid, which would cause them to function less effectively & prevent long-duration contraction

Question 4

Slow - Twitch Fibres: Adaptations

Answer 4

> A large store of myoglobin ( molecule that stores oxygen )

> Rich supply of blood vessels to deliver oxygen and glucose for aerobic respiration

> Numerous mitochondria to produce ATP

Question 5

Fast - Twitch Fibres: What function do they perform?

Answer 5

> Contract more rapidly and produce powerful contractions but only for a short period

> Adapted to intense exercise e.g. weight lifting

Question 6

Fast - Twitch Fibres: Where are they found in humans?

Answer 6

> Most common in muscles such as the biceps, which need to do short bursts of intense activity

Question 7

Fast - Twitch Fibres: Adaptations

Answer 7

> Thicker and more numerous myosin filaments

> A high concentration of glycogen

> A high concentration of enzymes involved in anaerobic respiration which provides ATP rapidly

> A store of phosphocreatine

Question 8

What is phosphocreatine?

Answer 8

> A molecule that can rapidly generate ATP from ADP in anaerobic conditions and so provide energy for muscle contraction