Topic 4 - Bioenergetics ( 8. anaerobic respiration )

Question 1

What is the difference between aerobic respiration and anaerobic respiration?

Answer 1

aerobic respiration uses oxygen and anaerobic respiration does not use oxygen

Question 2

Describe the process of anaerobic respiration

Answer 2

• Anaerobic respiration is the incomplete breakdown of glucose and produces lactic acid
• As the breakdown of glucose is incomplete, much less energy is released than during aerobic respiration

Question 3

What is the word equation for anaerobic respiration?

Answer 3

glucose => lactic acid + (small amount of) energy released

Question 4

When is anaerobic respiration used?

Answer 4

when insufficient oxygen is reaching the muscles

Question 5

What are the disadvantages of anaerobic respiration?

Answer 5

anaerobic respiration produces lactic acid which is poisonous

• We can only tolerate small amounts of lactic acid in our body
• If muscles are subjected to long periods of vigorous activity they become fatigued, i.e. they stop contracting efficiently
• One cause of muscle fatigue is the build up of lactic acid in the muscles
• Blood flowing through the muscles removes the lactic acid
• During and after exercise, we breathe heavily to take in extra oxygen to oxidise the lactic acid

Question 6

In order to neutralise lactic acid production, we breathe heavily to take in extra oxygen. Describe this process

Answer 6

• The extra oxygen is called the oxygen debt
• The heart continues to pump faster
• The breathing rate remains high
• This delivers the extra oxygen to the muscles
• This pays back the oxygen debt