Energy Systems In Muscle Cells

Question 1

During vigorous exercise

Answer 1

Cells start to respire anaerobically (fermentation) because they do not receive an adequate supply of oxygen

Question 2

During fermentation

Answer 2

The only stage of respiration that can occur is glycolysis

Question 3

In fermentation glucose is broken down

Answer 3

Into pyruvate which is then converted into lactate

Question 4

The conversion of pyruvate to lactate

Answer 4

Involves the transfer of hydrogen from NADH

Question 5

ATP can continue to be produced through glycolysis

Answer 5

Because NAD is continually regenerated as lactate builds up

Question 6

Lactate gathers in muscle cells

Answer 6

Causing fatigue and an “oxygen debt” to build up

Question 7

The oxygen debt gets repaid when

Answer 7

Exercise come to a halt and energy from aerobic respiration is used to convert lactate back to pyruvate

Question 8

Body movements are controlled by

Answer 8

The action of skeletal muscle fibres (these are the muscles attached to the bone)

Question 9

Skeletal muscle fibres fall into two categories:

Answer 9

Slow-twitch muscle fibres and fast-twitch muscle fibres

Question 10

Slow-twitch fibres rely on aerobic respiration to

Answer 10

Make ATP, have many mitochondria, a large blood supply, high concentration of myoglobin and use fats as fuel

Question 11

Fast-twitch fibres rely on glycolysis only to

Answer 11

Make ATP, have few mitochondria, a smaller blood supply, low concentrations of myoglobin and use glycogen as fuel

Question 12

Activities using fast twitch muscles include

Answer 12

Sprinting and weightlifting

Question 13

Activities using slow twitch muscles include

Answer 13

Endurance sports such as long distance running and cross-country skiing