Bio 12 - Respiration

Question 1

What does glycolysis do?

Answer 1

It makes pyruvate from glucose

Question 2

Where does glycolysis happen?

Answer 2

In the cytoplasm

Question 3

What are the two stages of glycolysis?

Answer 3

Phosphorylation and oxidation

Question 4

How is ATP used in the first stage of phosphorylation.

Answer 4

It is used to phosphorylate glucose to triose phosphate

Question 5

What is the overall net gain of glycolysis?

Answer 5

2 ATP and 2 reduced NAD

Question 6

What does phosphorylation produce?

Answer 6

1 glucose molecule and 1 ADP molecule

Question 7

How is hexose bisphosphate formed in glycolysis?

Answer 7

ATP is used to add another phosphate that forms hexose bisphosphate

Question 8

What does hexose bisphosphate split into?

Answer 8

Triose phosphate

Question 9

When triose phosphate is oxidised what is formed?

Answer 9

2 pyruvate molecules

Question 10

Why is there only a net gain of 2 ATP when 4 Amp are produced?

Answer 10

Because 2 are used up in stage one

Question 11

In anaerobic respiration what is pyruvate converted into?

Answer 11

Ethanol or lactate

Question 12

How come glycolysis can continue even when there is little oxygen

Answer 12

Fermentation regenerates oxidised NAD so glycolysis can continue even with little oxygen

Question 13

what does the link reaction do?

Answer 13

It converts pyruvate to acetyl coenzyme A. Pyruvate is decarboxylated

Question 14

How many times does the link reaction occur in a molecule?

Answer 14

Twice

Question 15

For each glucose molecule what is produced?

Answer 15

• 2 molecules of acetyl coenzyme A (to the Kreb cycle)
• 2 CO2 molecules (released as waste)
• 2 molecules of reduced NAD (go to oxidative phosphorylation)

Question 16

Where does the kerb cycle take place?

Answer 16

The matrix of mitochondria

Question 17

How many times does the kerb cycle take place?

Answer 17

Once for every pyruvate molecule and goes around twice for every glucose molecule

Question 18

Whats the first step of the Kerb cycle?

Answer 18

1. Acetyl coenzyme A from link reaction combines with a 4-carbon molecule to form a 6-carbon molecule.
   - Coenzyme A goes back to the link reaction to be used again

Question 19

What is the second step of the Kerb Cycle?

Answer 19

• 6 carbon citrate molecule converted into 5 carbon molecule
• Decarboxylation occurs
• Dehydrogenation occurs
• Hydrogen used to produce reduced NAD

Question 20

What is the third step of the Kerb Cycle?

Answer 20

• 5 carbon molecule converted to 4 carbon molecule
• Decarboxylation and dehydrogenation occur, produces one reduced FAD and two of reduced NAD
• ATP is produced.

Question 21

What are the products of the Kerb Cycle and where do they go?

Answer 21

• 1 coenzyme A = reused in the link reaction
• Oxaloacetate = regenerated for Kreb Cycle
• 2 CO2 = released as a waste product
• 1 ATP = used for energy
• 3 reduced NAD = to oxidative phosphorylation
• 1 reduced FAD = to oxidative phosphorylation

Question 22

What does oxidative phosphorylation produce?

Answer 22

Lots of ATP

Question 23

What is oxidative phosphorylation?

Answer 23

It is the process where the energy carried by electrons is used to make ATP

Question 24

What does oxidative phosphorylation involve?

Answer 24

the electron transport chain and chemiosmosis

Question 25

Explain the process of oxidative phosphorylation. (6 stages)

Answer 25

1. H atoms are released from reduced NAD and reduced FAD as they are oxidised to NAD and FAD
2. Electrons move down the electron transport chain
3. Energy used by electron carriers to pump protons from the mitochondrial matrix into the inter membrane space
4. Conc of protons now higher in inter membrane space than in the matrix
5. Protons move down the electrochemical gradient, back across the inner mitochondrial membrane and into the mitochondrial matrix
6. In the mitochondrial matrix the protons, electrons and O2 combine to form water. Oxygen is said to be the final electron acceptor

Question 26

Overall how much ATP can be made from one glucose molecule during respiration?

Answer 26

32 ATP