4. Bioenergetics (respiration, metabolism and exercise)

Question 1

What is respiration?

Answer 1

Respiration is the process of transferring energy from the break down of glucose

Question 2

Is respiration an endothermic or exothermic reaction?

Answer 2

Exothermic

Question 3

What does respiration transfer energy to?

Answer 3

• Smaller molecules to produce larger ones
• Muscles to contract (movement)
• In mammals and birds it keeps body temperature steady

Question 4

What is metabolism?

Answer 4

The sum of all the chemical reactions in an organism

Question 5

What are the two types of respiration?

Answer 5

• Aerobic respiration
• Anaerobic respiration

Question 6

What is aerobic respiration?

Answer 6

• Respiration in the presence of oxygen
• It is the most efficient way of transferring energy from glucose

Question 7

What is anaerobic respiration?

Answer 7

• Respiration in the absence of oxygen
• It is the incomplete breakdown of glucose, making lactic acid

Question 8

Where does aerobic respiration take place?

Answer 8

Mitochondria

Question 9

When does aerobic respiration take place?

Answer 9

All the time in plants and animals

Question 10

When does anaerobic respiration take place?

Answer 10

Anaerobic respiration occurs when your body is doing vigorous exercise and there isn’t enough oxygen being supplied to the muscles

Question 11

Where does anaerobic respiration take place?

Answer 11

In plants and yeast cells

Question 12

What is the equation for anaerobic respiration in muscles?

Answer 12

Glucose ——> Lactic acid

Question 13

What is the equation for anaerobic respiration in plant and yeast cells?

Answer 13

Glucose —-> ethanol + carbon dioxide

Question 14

Why does anaerobic respiration transfer less energy than aerobic respiration?

Answer 14

As glucose is unable to be fully oxidised, so it does not transfer as much energy as aerobic

Question 15

What is the equation for aerobic respiration?

Answer 15

Glucose + oxygen —-> carbon dioxide + water

Question 16

What is fermentation?

Answer 16

Anaerobic respiration in yeast cells

Question 17

What does the carbon dioxide do in fermentation?

Answer 17

It makes the bread rise

Question 18

What is the ethanol used for after fermentation?

Answer 18

Beers and wine

Question 19

Why does respiration increase while exercising?

Answer 19

• While exercising, the muscles contract more
• This leads to more energy being required, hence increasing respiration

Question 20

What can a build up of too much lactic acid cause for a long period of time?

Answer 20

Muscle fatigue (muscles contract less efficiently) which causes oxygen debt

Question 21

What is oxygen debt?

Answer 21

The amount of oxygen required to react with the lactic acid in order to break down and remove it from the cells

Question 22

Why does the pulse and breathing rate stay high whilst levels of lactic acid are high?

Answer 22

So that the blood can quickly transport the lactic acid to the liver to be converted back to glucose