KA8- Energy systems in muscle cells

Question 1

Describe the process of lactate metabolism.

Answer 1

1. During vigorous exercise, the muscle cells do not get sufficient oxygen to support the electron transport chain.
2. Under these conditions, pyruvate is converted to lactate.
3. This conversation of pyruvate to lactate involves the transfer of hydrogen from the NADH to pyruvate in order to produce lactate.
4. This regenerates the NAD needed to maintain ATP production through glycolysis.
5. Lactate accumulates and muscle fatigue cuts.
6. The oxygen debt is repaid when exercise is complete. This allows respiration to provide the energy to converts lactate back to pyruvate and glucose in the liver.

Question 2

What is the function of skeletal muscles?

Answer 2

To bring about movement of the body.

Question 3

What are the two types of skeletal muscle fibres?

Answer 3

Fast twitch muscle fibres and slow twitch muscle fibres.

Question 4

How do slow twitch muscle fibres contract?

Answer 4

They contract relatively slowly, but can sustain contractions for longer

Question 5

What do slow twitch muscle fibres rely on to generate ATP?

Answer 5

Aerobic respiration

Question 6

Where are slow twitch muscle fibres useful?

Answer 6

They are useful for endurance activities such as cycling, long distance running.

Question 7

How do fast twitch muscle fibres contract?

Answer 7

They contract relatively quickly over short periods.

Question 8

Where are fast twitch muscle fibres useful?

Answer 8

They useful for activities such sprinting and weightlifting.

Question 9

How do fast twitch muscle fibres generate ATP?

Answer 9

Through glycolysis.

Question 10

What muscle fibres do most humans contain.

Answer 10

They contain a mixture of both slow twitch and fast twitch muscle fibres.