Energy systems in muscle cells

Question 1

When is lactate produced

Answer 1

During vigorous exercise, the muscles do not get sufficient energy to support the electron transport chain. Under these conditions, pyruvate is converted into lactate.

Question 2

The two types of muscle fibres are

Answer 2

Slow twitch and Fast twitch

Question 3

Describe slow-twitch muscle fibres

Answer 3

they contract relatively slowly and can sustain contractions for longer. They rely on aerobic respiration and have many mitochondria, a large blood supply and high concentration of myoglobin.

Question 4

Describe fast-twitch muscle fibres

Answer 4

They contract relatively quickly over short periods of time. They generate ATP through glycolysis and so have fewer mitochondria, and a lower blood supply.

Question 5

What is important about myoglobin

Answer 5

It has a stronger affinity for oxygen than haemoglobin.

Question 6

What are the major storage fuels of fast and slow twitch

Answer 6

Fast - Glycogen
Slow - Fats

Question 7

List sports that require higher concentrations of each muscle fibre

Answer 7

Slow - Cross country, long distance cycling
Fast - Sprinting, weightlifting