Enegry Systems In Muscle Cells

Question 1

What happens during vigorous exercise?

Answer 1

• muscles do not get sufficient oxygen to support the electron transport chain

Question 2

What happens when their isn’t sufficient oxygen?

Answer 2

• pyruvate is converted into lactate instead of following the normal pathway

Question 3

What is transferred to pyruvate to produce more lactate?

And what does it cause?

Answer 3

• the hydrogen from the NADH produced in glycolysis

- regenerating the NAD needed to maintain ATP production during glycolysis

Question 4

What happens as lactate builds up?

Answer 4

• muscle fatigue occurs and an oxygen debt is built up

Question 5

What happens when exercise stops?

Answer 5

• the oxygen debt is repaid allowing respiration to provide the energy needed to convert lactate back to pyruvate and glucose in the liver

Question 6

What are skeletal muscles made up of?

Answer 6

• fast and slow twitch muscle fibres

Question 7

What do slow twitch muscle fibres do?

Answer 7

• contract relatively slowly but can sustain the contractions for a long time relying on ATP from respiration

Question 8

What do slow twitch muscle fibres have?

Answer 8

• many mitochondria
• large blood supply
• high concentration of of the oxygen-storing protein myoglobin

Question 9

What are slow twitch muscle fibres good for?

Answer 9

• endurance activities
  > long distance running
  > cycling

Question 10

What is slow twitch muscle fibres major storage fuel?

Answer 10

• fats

Question 11

What do fast twitch muscle fibres do?

Answer 11

• contract relatively quickly but only for a short period of time relying on ATP from glycolysis

Question 12

What do fast twitch muscle fibres have?

Answer 12

• fewer mitochondria

- lower blood supply

Question 13

What are fast twitch muscle fibres good for?

Answer 13

• short bursts of activities
  > weight lifting
  > sprinting

Question 14

What is fast twitch muscle fibres majors fuel?

Answer 14

• glycogen