Module 5 - Respiration

Question 1

What does respiration produce?

Answer 1

ATP

Question 2

Where does glycolysis occur and what type of process is it?

Answer 2

It occurs in the cytoplasm and is an anaerobic process

Question 3

What is the first stage of glycolysis?

Answer 3

Glucose is phosphorylated and produces one molecule of ADP. It is phosphorylated again to produce hexose bisphosphate. This also produces ADP

Question 4

What does hexose bisphosphate produce once broken down in the first stage of glycolysis?

Answer 4

It breaks down into 2 triose phosphate molecules

Question 5

What happens in the second stage of glycolysis?

Answer 5

Triose phosphate is oxidised, forming two molecules of pyruvate. NAD collects these H ions forming reduced NAD.

Question 6

What is the net gain of ATP in glycolysis?

Answer 6

2

Question 7

If it is anaerobic respiration, what will pyruvate be produced into?

Answer 7

The two pyruvate molecules will be produced into ethanol and lactic acid using reduced NAD.

Question 8

In anaerobic respiration, what does the process do to allow glycolysis to continue?

Answer 8

The ethanol or lactate can regenerate into oxidised NAD.

Question 9

After glycolysis, where does the pyruvate enter and how?

Answer 9

The mitochondrial matrix and through active transport

Question 10

What happens in the link reaction?

Answer 10

Pyruvate will be decarboxylated and then oxidised to form acetate reduced NAD. Acetate is then combine with coenzyme A to form acetyl coenzyme A

Question 11

What is the first stage of the Krebs Cycle?

Answer 11

Acetyl conenzyme A binds to a 4-carbon compound (oxaloacetate) which produces a 6-carbon compound. Coenzyme A is released back to the link reaction.

Question 12

What is the second stage of the Krebs Cycle?

Answer 12

Decarboxylation occurs and dehydrogenation occurs which removes CO2 and hydrogen as a waste product. The hydrogen binds to the NAD produce reduced NAD.

Question 13

What is the third stage of the Krebs cycle?

Answer 13

Decarboxylation and dehydrogenation occurs again. This produces one molecule of CO2, 2 molecules of FAD and 2 molecules of NAD.
ATP is made by a transfer of a phosphate group from another molecule. This is substrate-level phosphorylation

Question 14

What is oxidative phosphorylation?

Answer 14

The synthesis of ATP from the oxidisation of NAD and FAD and the electron transport chain

Question 15

How does the concentration increase from the matrix to the intermembrane space?

Answer 15

Reduced NAD and FAD are oxidised to produce H* ions. These are split to form electrons and protons which go down the electron carrier and loses energy which is used to pump proteins.

Question 16

What is it known as when there is a higher concentration in the intermembrane than the matrix?

Answer 16

Electrochemical gradient

Question 17

What does the electrochemical gradient allow to happen?

Answer 17

The diffusion of protons across the inner membrane via ATP synthase into the matrix. This facilitates the reaction of ADP + Pi into ATP.

Question 18

How is water made in respiration?

Answer 18

Oxygen is said to be the final electron acceptor which allows the continuation of the flow of electrons. This therefore means that water can be made in the reaction

Question 19

Where does anaerobic respiration take place?

Answer 19

in the cytoplasm

Question 20

How does anaerobic respiration take place in animals?

Answer 20

2x pyruvate molecules are oxidised to produce reduced NAD. This produces lactate. The Reduced NAD is the reoxidised so that it can be-re-used to oxidise triose phosphate into pyruvate and therefore the reaction can continue.0

Question 21

How much ATP does anaerobic respiration make compared to aerobic respiration?

Answer 21

Anaerobic - 2
Aerobic - 38

Question 22

What molecule is the only molecule that can diffuse across the mitochondrial matrix?

Answer 22

Pyruvate