KA8 - Lactate Metabolism

Question 1

What happens during vigorous exercise?

Answer 1

The muscle cells do not get enough sufficient oxygen to support the electron transport chain

Question 2

What is pyruvate converted into under anaerobic conditions?

Answer 2

Lactate

Question 3

What does the conversion of pyruvate into lactate involve?

Answer 3

The transfer of hydrogen from NADH produced during glycolysis to pyruvate in order to produce lactate

This regenerates the NAD need to maintain ATP production through glycolysis

Question 4

What is the first stage of lactate metabolism?

Answer 4

Lactate accumulates and muscle fatigue occurs

Question 5

What is the second stage of lactate metabolism?

Answer 5

The oxygen dept is repaid when exercise is complete

Question 6

What is the third stage of lactate metabolism?

Answer 6

This allows respiration to provide the energy to convert lactate back to pyruvate and glucose in the liver

Question 7

What is skeletal muscle?

Answer 7

Skeletal muscles are muscles that are attached to some part of the skeleton and bring about movement of the body

Question 8

What are the two types of skeletal muscle?

Answer 8

Slow twitch muscle fibres

Fast twitch muscle fibres

Question 9

Give an account of slow twitch muscle fibres

Answer 9

Slow twitch muscle fibres contract relatively slowly but can sustain their contractions for longer

Slow twitch muscle fibres rely on aerobic respiration to generate ATP. They therefore have many mitochondria in their cells and a large blood supply

Question 10

What activities are slow twitch muscle fibres useful for?

Answer 10

Long distance running and cycling

Question 11

What do slow twitch muscle fibres have a high concentration of?

Answer 11

The protein myoglobin which is good at storing oxygen

Question 12

What is the major fuel storage in slow twitch muscle fibres?

Answer 12

Fats

Question 13

Give an account on fast twitch muscle fibres

Answer 13

Fast twitch muscle fibres contract relatively quickly but can only sustain this over a short periods of time

Fast twitch muscle fibres generate ATP through glycolysis only. They therefore have fewer mitochondria and a lower blood supply compared to slow twitch muscle fibres

Question 14

What activities are fast twitch muscle fibres useful for?

Answer 14

Sprinting and weightlifting

Question 15

What is the major storage fuel in fast twitch muscle fibres?

Answer 15

Glycogen. As glycogen stores run low, muscle fatigue occurs