Respiration and Respiratory System

Question 1

Aerobic Respiration equation

Answer 1

Glucose + Oxygen —> Carbon dioxide + Water

Question 2

Anaerobic Respiration (in humans) equation

Answer 2

Glucose —> Lactic acid

Question 3

Why Aerobic Respiration is better than Anaerobic?

Answer 3

Produces 20x more energy

Question 4

Why is lactic acid formed?

Answer 4

No oxygen, needs to create energy

Question 5

Lactic acid concentration decreases some time after exercise, why?

Answer 5

Oxygen debt is being repayed

Question 6

Anaerobic Respiration in yeast equation

Answer 6

Glucose —> Ethanol + Carbon dioxide

Question 7

Process where yeast respires anaerobically

Answer 7

Fermentation

Question 8

Process of breathing in (QWC)

Answer 8

• Intercostal muscles contract
• Ribcage moves up and out
• Diaphragm flattens
• Volume of lungs (thoracic cavity) increases and pressure decreases
• Air moves into lungs as pressure outside is higher than inside

Question 9

Process of breathing out (QWC)

Answer 9

• Intercostal muscles relax
• Ribcage moves down and in
• Diaphragm domes up (becomes done shaped)
• Volume of lungs (thoracic cavity) decreases and pressure inside lungs increases
• Air moves out of lungs as pressure inside is higher than outside

Question 10

What happens at an alveolus and how is it suited to its function? (QWC)

Answer 10

• Gas exchange occurs
• Oxygen diffuses from alveolus into bloodstream to be transported to the cells for respiration
• CO2 diffuses from bloodstream into alveolus as it is a waste produced in cells by respiration
• Suited to gas exchange because of thin walls (less diffusion distance), moist walls (gases need to dissolve for diffusion) and good blood supply to transport gases

Question 11

Importance of Aerobic and Anaerobic Respiration in living things (QWC)

Answer 11

• Both produce energy inside cells of all living things
• Energy is used for growth and movement
• Aerobic produces 20x more energy than Anaerobic
• Aerobic uses oxygen
• Anaerobic takes place without oxygen/when oxygen has run out in cells
• Anaerobic cannot occur all the time as poisonous substances are made in cells E.g. Lactic acid in humans, ethanol in yeast

Question 12

After Anaerobic Respiration

Answer 12

• Lactic acid is removed from muscles in bloodstream
• On reaching the liver, some lactic acid is broken down to carbon dioxide and water, using up oxygen in process so high level of oxygen consumption may persist after exercise whilst lactic acid oxidised
• Build up of lactic acid to be oxidised later creates oxygen debt

Question 13

Oxygen Debt

Answer 13

First O2 to get to muscles isn’t used for respiration, it’s used to break down lactic acid