Respiration

Question 1

Which two forms of energy are released by respiration?

Answer 1

Chemical (ATP) and heat energy

Question 2

Draw and label a mitochondrion

Answer 2

Mitochondria consist of an outer and inner double membrane; intermembrane space; cristae; matrix; DNA and ribosomes.

Question 3

Give the four stages of aerobic respiration

Answer 3

Glycolysis, the link reaction, the Krebs cycle, oxidative phosphorylation

Question 4

Give the two stages of anaerobic respiration

Answer 4

Glycolysis, fermentation

Question 5

Where does glycolysis happen?

Answer 5

The cytoplasm

Question 6

What are the three products of glycolysis?

Answer 6

2 reduced NAD, a net of 2 ATP, 2 pyruvate

Question 7

Why is NADH described as reduced NAD?

Answer 7

NAD has gained a hydrogen atom

Question 8

What is the purpose of fermentation in anaerobic respiration?

Answer 8

To oxidise reduced NAD, so it can continue to be used in glycolysis

Question 9

In anaerobic respiration, how many ATP are produced by fermentation?

Answer 9

0

Question 10

What are the products of fermentation in animals?

Answer 10

Lactic Acid, NAD

Question 11

What are the products of fermentation in plants?

Answer 11

Ethanol, CO2, NAD

Question 12

What happens to lactic acid after fermentation?

Answer 12

It is transported to the liver and converted back into pyruvate

Question 13

Where does the link reaction occur?

Answer 13

The mitochondrial matrix

Question 14

What are the three products of the link reaction?

Answer 14

Acetyl coA, CO2, reduced NAD (x2 per glucose)

Question 15

How many reduced NAD are produced in one turn of the Krebs cycle?

Answer 15

3

Question 16

How many reduced FAD are produced in one turn of the Krebs cycle?

Answer 16

1

Question 17

By which process is ATP produced in the Krebs cycle?

Answer 17

Substrate level phosphorylation

Question 18

How many ATP are produced in one turn of the Krebs cycle?

Answer 18

1

Question 19

Which enzyme removes hydrogen in glycolysis, the link reaction and the Krebs cycle?

Answer 19

Dehydrogenase

Question 20

Which enzyme produces CO2 in the link reaction and the Krebs cycle?

Answer 20

Decarboxylase

Question 21

Name three co-enzymes involved in respiration

Answer 21

NAD, FAD, acetyl coA

Question 22

What is the energy yield in ATP for each reduced NAD in oxidative phosphorylation?

Answer 22

3

Question 23

What is the energy yield in ATP for each reduced FAD in oxidative phosphorylation?

Answer 23

2

Question 24

What is the final electron acceptor in respiration?

Answer 24

Oxygen

Question 25

Why is the theoretical yield of 38 ATP from aerobic respiration not actually reached?

Answer 25

proton losses (leaky membranes) as well as the cost of moving pyruvate and ADP into the mitochondrial matrix

Question 26

Explain endosymbiotic theory

Answer 26

Mitochondria and chloroplasts were once separate organisms that were absorbed by a larger cell through endocytosis.

Question 27

At which stage do lipids enter respiration?

Answer 27

Lipids are broken down to glycerol and fatty acids. Glycerol enters as TP in glycolysis, fatty acids are broken into 2C fragments and enter the Krebs cycle as acetate.

Question 28

At which stage do proteins enter respiration?

Answer 28

Proteins are hydrolysed to amino acids and deaminated in the liver, forming a keto acid and ammonia. The keto acid could enter glycolysis or the krebs cycle