Unit 1- Energy Systems

Question 1

What is lactate metabolism?

Answer 1

During vigorous exercise, the muscle cells do not get sufficient oxygen to support the electron transport chain, meaning pyruvate is converted to lactate.

Question 2

Describe the conversion of glucose to lactate.

Answer 2

1. Glucose breaks down into pyruvate and NAD converts to NADH.
2. Pyruvate breaks down into lactate and NADH converts to NAD.

Question 3

Describe how an oxygen debt forms.

Answer 3

Lactate accumulates when muscles respire without oxygen causing muscle fatigue. During the formation of lactate an oxygen debt accumulates which is repaid when excercise is complete and oxygen becomes available and the lactate is converted back to pyruvate.

Question 4

What are the two types of skeletal muscle?

Answer 4

Slow twitch muscle fibres, fast twitch muscle fibres.

Question 5

Describe slow twitch muscle fibres.

Answer 5

Contract slowly but sustain contractions for a long time.
Good for endurance like long distance running.
Rely on aerobic respiration for ATP.
Have many mitochondria.
A large blood supply
Storage fuel is fats.

Question 6

Describe fast twitch muscle fibres.

Answer 6

Contact quickly but cannot sustain contractions for as long as slow twitch muscle fibres.
Good for sprinting, weightlifting.
Generate ATP through glycolysis only.
Have few mitochondria and a lower blood supply.
Storage fuel is Glycogen.