Respiration

Question 1

What coenzymes are used in respiration?

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Answer 1

NAD and FAD

Coenzyme A

Question 2

Outline glycolysis (occurs in cytoplasm)
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Answer 2

Glucose is phosphorylated by 2x ATP in hexose 1,6 bis phosphate

This is then splits to 2x TP

2x TP oxidised into 2x pyruvate

forming 2x reduced NAD and a net gain of 2x ATP

Question 3

Outline Link Reaction (occurs in matrix)

▪(what 2 molecules produced)
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Answer 3

Pyruvate gets decarboxylated and oxidised forming 1x reduced NAD

Forms Acetate which Binds with Co enzyme A
Forming Acetyl CoA

Question 4

Outline Krebs cycle (occurs in matrix)

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Answer 4

Acetyl CoA binds with oxaloacetate forming citrate (citrate synthase catalyst)

Citrate decarboxylated and forms 1x CO2 and 1x reduced NAD

The 5 carbon compound is decarboxylated and regenerates oxaloactate.

It forms 2x reduced NAD, 1x reduced FAD and 1x ATP

(cycle runs twice)

Question 5

Outline oxidative phosphorylation

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Answer 5

Reduced NAD and reduced FAD are oxidised at the mitochondrial inner membrane forming H+ ions

These ions are transported across the cristae into the intermembrane space via active transport against concentration gradient through proton pumps.

(This sets up a proton gradient)

Ions diffuse back into matrix via facilitated diffusion through ATP synthase which phosphorylates ADP with inorganic phosphate forming ATP

Question 6

What is oxygen?

Answer 6

Final electron acceptor

Question 7

Why is theoretical yield of ATP lower than actual yield?

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Answer 7

Leakage of H+ across membrane

ATP used to actively transport pyruvate into mitochondria

Question 8

Outline an aerobic respiration in animals

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Answer 8

Pyruvate reduced using 2x reduced NAD into lactate

Net of 2x ATP formed

Question 9

Outline anaerobic respiration in plants

Answer 9

Pyruvate converted into ethanal and reduced into ethanol by 2x reduced NAD