Respiration

Question 1

What are anabolic reactions?

Answer 1

Metabolic reactions in body that build up large molecules from smaller ones.

Question 2

What are catabolic reactions?

Answer 2

Breakdown of larger molecules into smaller ones

Question 3

What is substate-level phosphorylation?

Answer 3

ATP is made without transfer of substrates across a membrane.

Question 4

What is chemeosmosis?

Answer 4

The formation of ATP using ATP synthase and a membrane.

Question 5

Why does the theoretical yield 32 ATP molecules made in anerobic respiration of molecules rarely occur?

Answer 5

Because some of the hydrogen ions leak across mitochondrial membrane, reducing the electrochemical gradient.
Some ATP made is used for active transport of pyruvate into mitochondrion for link reaction.
Some ATP used to transport reduced NAD made in glycolysis into mitochondria.

Question 6

What does pyruvate act as in the anerobic respiration in mammals?

Answer 6

It acts as the electron accceptor in place of the mixing oxygen when NADH dissociates its H+ and electron. This recycles NAD so it is again ready to dehydrogenate glucose.

Question 7

What is formed in anerobic respiration in mammals vs yeast?

Answer 7

Lactate in animals and ethanol in yeast (via permentation)

Question 8

What is the net production of ATP in anaerobic respiration and aerobic respiration?

Answer 8

2 and 32

Question 9

Why is there a lower ATP yield in anaerobic respiration of both yeast and mammals?

Answer 9

No oxygen=no final electron acceptor.
So there is no oxidative phosphorylation, no Krebs cycle, no link reaction.
Only 2 ATP made compared to 32 in aerobic respiration.

Question 10

Why is anaerobic respiration important?

Answer 10

“It allows NAD to be recycled”
“so glycolysis can continue”
“therefore a small number of ATP is produced”

Question 11

Why do lipids give off the most amount of energy compared to other respiratory substrates?

Answer 11

Because they have highest number of H ions made from breakdown of lipids

Question 12

What are respiratory substrates?

Answer 12

Alternative substrates to produce ATP when oxygen is not available.

Question 13

What is the reaction pathway for lipids?

Answer 13

Lipid–glycerol+fatty acids
Glycerol–TP (for glycolysis)
Fatty acids–acetyl CoA

Question 14

What is the reaction pathway for amino acids?

Answer 14

Protein–Amino Acid (deaminated)–pyruvate
AA–Acetyl CoA

Question 15

What is RQ?

Answer 15

Respiratory Quotient is the ratio of the volumes of oxygen consumes and carbon dioxide given off in respiration.

=CO2 produced/02 consumed

Question 16

What does an RQ>1 mean?

Answer 16

Anaerobic respiration is taking place, as more CO2 is being made than 02 being used.

Question 17

What are the RQs of carbs, proteins and lipids?

Answer 17

1, 0.9 and 0.7
Lipids and proteins have lower RQ value as more oxygen is needed to oxidise them in comparison to carbs.

Question 18

Why do plants sometimes have a lower RQ value?

Answer 18

Because the CO2 released in respiration is used for photosynthesis and can’t be measured.