Lesson 2: Exercise

Question 1

What does the body do when we exercise?

Answer 1

• During exercise the human body reacts to the increased demand for
  energy.

Question 2

How does the body react to the increased demand of energy during exercise?

Answer 2

• Heart rate
• Breath volume
• Breathing rate
• ALL INCREASE!! to supply the muscles with more oxygenated blood!!

Question 3

What happens when insufficient oxygen is supplied to muscle cells during exercise?

Answer 3

• Anaerobic respiration.
• Build up of lactic acid
• Over long periods of vigorous exercise, lactic acid causes muscles to become fatigued and stop contracting efficiently.

Question 4

What is meant by “oxygen debt?”

Answer 4

• The amount of extra oxygen the body needs after exercise to react with the accumalated lactic acid and remove it from cells.
  breathing heavily after exercise

Question 5

What happens to lactic acid when it is broken down?

Answer 5

• Blood, flowing through muscles, transports lactic acid to the liver where it is converted back to glucose.

Question 6

What causes lactic acid to be produced rather than CO2 in anaerobic respiration?

Answer 6

• Incomplete oxidation of glucose.