Anaerobic Respiration and Respiratory Substrates

Question 1

Ethanol Fermentation

Answer 1

Pyruvate decarboxylated and converted into ethanol
Ethanol accepts H+ from NADH
NAD reoxidised so used in glycolysis

Question 2

What is the enzyme called in the decarboxylation of pyruvate to ethanal?

Answer 2

Pyruvate Decarboxylase + Thiamine diphosphate

Question 3

What enzyme catalyses ethanal into ethanal?

Answer 3

Ethanol dehydrogenase

Question 4

How does lactate fermentation happen?

Answer 4

Pyruvate accepts H+ from NADH and is reduced by lactate dehydrogenase

Question 5

Why does anaerobic respiration occur?

Answer 5

Oxygen is not present as the final electron acceptor so protons not able to form water
Conc of protons in matrix increases and reduces proton gradient
Reduced NAD and FAD are not reoxidised
Therefore Krebs and Link stop

Question 6

What is the emzyme called in lactate fermentation?

Answer 6

Lactate Dehydrogenase

Question 7

What happens to lactate?

Answer 7

Taken to liver because muscle cells do not have the correct enzyme
Lactate converted to pyruvate and enters aerobic
Converted to glucose or glycogen

Question 8

What is a respiratory substrate?

Answer 8

Organic substance used in respiration releasing energy to make ATP

Question 9

Why do lipids have high energy content?

Answer 9

They have lots of H+ so lots of energy, most energy content per gram

Question 10

Why is the ATP yeild low in anaerobic?

Answer 10

Only energy source is glycolysis so a net of 2 glucose
Glucose is only partly broken down
1/15 of aerobic yield

Question 11

What is ketogenesis?

Answer 11

Excess acetyl coA from beta oxidation is converted into ketone bodies which is fuel

Question 12

What are the steps of beta oxidation?

Answer 12

1. Each fatty acid is combined with coA where they become fatty acyl CoA
2. Fatty acyl coA transported to the matrix where it is broken down to 2C acetyl group attached to coA
3. Generate NADH and FADH
4. Acetyl groups released from coA and go into krebs

Question 13

What happens to glycerol?

Answer 13

Glycerol converted into glyceraldehyde-3-phosphate and then to glucose or pyruvic acid

Question 14

How are proteins respired?

Answer 14

Deaminated and keto acid produced used in respiration as acetyl coA and oxaloacetate acid

Question 15

How are other carbs respired?

Answer 15

Disacarides are digested into mono

Fructose and Lactose changed by isomeriase emzymes

Question 16

Whats the equations for Respiratory Quotient?

Answer 16

RQ = CO2/O2

Question 17

What are the RQ values for Glucose, Triglyceride and protein?

Answer 17

Carbs is 1.0
Triglyceride is 0.7
Protein is 0.9