3.5 Respiration

Question 1

What is the 1st stage of aerobic respiration ?

Answer 1

Glycolysis

Question 2

What is the 2nd stage of aerobic respiration ?

Answer 2

The link reaction

Question 3

What is the 3rd stage of aerobic respiration ?

Answer 3

The Krebs cycle

Question 4

What is the final stage of aerobic respiration ?

Answer 4

Oxidative phosphorylation

Question 5

Where does Glycolysis take place ?

Answer 5

In the cytoplasm

Question 6

Where does the link reaction take place ?

Answer 6

In the mitochondrial matrix

Question 7

Where does the Krebs cycle take place ?

Answer 7

In the mitochondrial matrix

Question 8

Where does oxidative phosphorylation take place ?

Answer 8

In the Cristae

Question 9

What is the first step of glycolysis ?

Answer 9

Glucose is phosphorylated to glucose phosphate using 2 molecules of ATP

Question 10

What is the second step of glycolysis ?

Answer 10

The production of triose phosphate

Question 11

What is the third step of glycolysis ?

Answer 11

Oxidation of triode phosphate to produce pyruvate with a net gain of ATP and reduced NAD

Question 12

What are the products of glycolysis ?

Answer 12

• 2 pyruvate
• net gain of 2 ATP
• 2 NADH

Question 13

How many carbons does one pyruvate have ?

Answer 13

3 carbons

Question 14

How many carbons does one acetate have ?

Answer 14

2 carbons

Question 15

What is the first stage of the link reaction ?

Answer 15

The pyruvate made in glycolysis is oxidised into acetate- as one carbon is lost we can say pyruvate is being decarboxylated

Question 16

When pyruvate is oxidised into acetate, what happens to the NAD ?

Answer 16

NAD picks up the hydrogen and becomes reduced NADH

Question 17

How many times does the link reaction occur for one glucose molecule ?

Answer 17

The link reaction occurs twice for every glucose molecule

Question 18

What are the products of the link reaction for one glucose molecule ?

Answer 18

2 Acetyl CoA
2 CO2 released
2 reduced NAD

Question 19

What is the first stage of the Krebs cycle ?

Answer 19

Acetyl CoA reacts with Oxalocetate (4 carbon molecule) to produce Citrate (6 carbon molecule) that enters the cycle

Question 20

What is the second stage of the Krebs cycle ?

Answer 20

A series of redox reactions occur, ATP is produced by substrate level phosphorylation and carbon dioxide is lost

Question 21

What are the products of the Krebs cycle for one glucose molecule ?

Answer 21

6 Reduced NAD
2 Reduced FAD
2 ATP
4 CO2

Question 22

What are the products of glycolysis ?

Answer 22

2 Pyruvate
Net gain of 2 ATP (As 4 produced but 2 needed at start of glycolysis)
2 NADH

Question 23

What is the equation for respiration ?

Answer 23

C6H12O6 + 6O2 –> 6CO2 + 6H2O

Question 24

What is the chemiosmotic theory ?

Answer 24

​The synthesis of ATP through the movement of protons down their concentration gradient across a semipermeable membrane, catalysed by ATP synthase.

Question 25

Where does anaerobic respiration occur ?

Answer 25

Only in the cytoplasm

Question 26

What is substrate level phosphorylation ?

Answer 26

The formation of ATP from ADP and a phosphorylated intermediate, rather than from ADP and inorganic phosphate, Pi

Question 27

What does anaerobic respiration in animals produce ?

Answer 27

It forms lactate as it gains the H from reduced NAD

Question 28

When lactate is formed in anaerobic respiration what happens to the NAD ?

Answer 28

The NAD returns back to glycolysis so it can be reused and so that more ATP can be made

Question 29

What does anaerobic respiration in plants produce ?

Answer 29

Ethanol and Carbon dioxide

Question 30

Why can aerobic respiration not occur for a long time ?

Answer 30

As it causes a build up of lactic acid in muscles which causes fatigue and muscle cramps