Cjapter 12: Respiration

Question 1

Use of energy in living organisms

Answer 1

muscle contraction, protein synthesis, cell division, active transport, growth, the passage of nerve impulses and the maintenance of a constant body temperature

Question 2

Describe aerobic respiration

Answer 2

the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy

Question 3

State the balanced chemical equation for aerobic respiration:

Answer 3

C6H12O6 + 6O2 → 6CO2 + 6H2O

Question 4

Describe anaerobic respiration

Answer 4

the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen

Question 5

Energy released by anaerobic respiration in comparison to aerobic respiration

Answer 5

anaerobic respiration releases much less energy per glucose molecule than aerobic respiration

Question 6

State the balanced chemical equation for anaerobic respiration in yeast:

Answer 6

C6H12O6 → 2C2H5OH + 2CO2

glucose → alcohol + carbon dioxide

Question 7

State the word equation for anaerobic respiration in muscles during vigorous exercise

Answer 7

glucose → lactic acid

Question 8

Effect of lactic acid

Answer 8

lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt

Question 9

how the oxygen debt is removed after exercise

Answer 9

(a) continuation of fast heart rate to transport lactic acid in the blood from the muscles to the liver
(b) continuation of deeper and faster breathing to supply oxygen for aerobic respiration of lactic acid
(c) aerobic respiration of lactic acid in the liver