[FMS] NAM - aerobic metabolism

Question 1

what is another name for aerobic metabolism

Answer 1

Krebs cycle
Citric acid cycle
Tricarboxylic acid cycle
Common terminal pathway

Question 2

where does aerobic metabolism occur

Answer 2

mitochondrial matrix

Question 3

what happens in aerobic metabolism

Answer 3

oxidation of acetyl CoA to CO2 and water

Question 4

what tissues aerobically metabolise? and which ones do not?

Answer 4

all tissues that have mitochondria

not RBC or white muscle fibres

Question 5

• what are the functions of aerobic metabolism?

Answer 5

• energy trapping
• biosynthesis of intermediates

Question 6

• how many decarboxylations occur in TCA?

Answer 6

2 (decarboxylation = when co2 is removed which happens 2 times in TCA cycle)

Question 7

draw out the TCA cycle including enzymes and where the following are made: H, GTP, CO2, and FADH2

Answer 7

Question 8

what is the link reaction

Answer 8

reaction for conversion pyruvate to Acetyl CoA, prep for TCA

Question 9

what kind of reaction is link reaction

Answer 9

decarboxylation

Question 10

what are the other cofactors involved in aerobic respiration (link reaction)

Answer 10

• thiamine pyrophosphate (thiamine VitB1)
• lipoic acid
• FAD (riboflavin: vitB2)
• Coenzyme A (panthothenic acid: vitB5)

Question 11

• what does coenzyme A form?

Answer 11

thioester bonds with carboxylic acids

Question 12

• where is the electron transport chain?

Answer 12

inner mitchondrial matrix

Question 13

what does the Electron Transport chain contain?

Answer 13

metal ions that undergo electron transfer reactions

Question 14

what do metal ions in the ETC prevent?

Answer 14

leakage of electrons

Question 15

what is the function of the ETC

Answer 15

to get:
NADH –>NAD+
FADH2 –> FAD
ADP –> ATP

Question 16

how does the ETC generate ATP

Answer 16

via the re-oxidation of NADH to NAD+ and FADH2 to FAD

Question 17

how many of the following enzyme reaction are there in the TCA cycle:

1. enzyme reactions that produce NADH and H+
2. enzyme reactions that produce FADH2
3. enzyme reactions that produce GTP

Answer 17

3 enzyme reactions produce NADH and H+

1 enzyme reaction produces FADH 2

1 enzyme reaction produces GTP

Question 18

what is the ATP yield of TCA

Answer 18

10(new)/12 ATP (old)

Question 19

which 3 enzyme steps in TCA cycle are highly exergonic & irreversible:

Answer 19

1. citrate synthase
2. isocitrate dehydrogenase
3. α-ketoglutarate dehydrogenase

Question 20

what is the definition of oxidative phosphorylation

Answer 20

process for the transfer of H atoms to oxygen

Question 21

where does oxidative phosphorylation take place

Answer 21

inner compartments of mitochondria

Question 22

which tissue does oxidative phosphorylation take place in, which cell does it NOT take place in

Answer 22

most tissues & cell types
(not red blood cells)

Question 23

what the function of oxidative phosphorylation

Answer 23

‘energy trapping’ direct phosphorylation of ADP to produce ATP

Question 24

What do we need oxygen for in oxidative phosphorylation

Answer 24

Oxygen is the terminal electron acceptor to generate ATP.

Question 25

what are 2 components of the electron transport chain

Answer 25

**H pair acceptors:** Flavin cofactors Coenzyme Q CoQ **Electron acceptors:** Iron sulphur proteins Cytochrome proteins

Question 26

what are the steps in the electron transport chain?

Answer 26

Question 27

what is redox potential

Answer 27

Redox potential, E’0, is a measure of the electron affinity of a molecule.

Question 28

what does a more positive or more negative redox potential mean

Answer 28

The more negative E’0, the more likely a molecule is to pass on electrons (reduce another molecule). Alternatively, the more positive E’0, the more readily a molecule will accept electrons (be reduced).

Question 29

how are H+ (protons) transferred from matrix to inter-membrane space

Answer 29

Energy released by electron transport is used to transfer protons (H+) from the matrix to the inter-membrane space

Question 30

what is the mechanism of ATP synthesis in oxidative phosphorylation (aerobic respiration)

Answer 30

- This pump is called the F1 ATP synthase. - The protons are going to fit inside of it and they’re going to spin it around - as it rotates around it forms ATP. - However in order to do that, you have to input adenosine diphosphate (ADP) and Pi, and that will yield ATP. - The protons go from the intermembrane space, back across the inner membrane into the matrix.

Question 31

what is the ATP yield in oxidative phosphorylation when NADH is reoxidised and when FADH2 produced

Answer 31

NADH reoxidised - 2.5 ATP FADH2 - 1.5 ATP

Question 32

What is the relationship between ADP/ATP concentration and O2 uptake in oxidative phosphorylation?

Answer 32

**Increased [ADP]** signals higher energy demand, promoting **increased O2 uptake** as the electron transport chain is more active in generating ATP. Conversely, **increased [ATP]** signals reduced energy demand, leading to **decreased O2 uptake** to prevent unnecessary oxygen consumption.

Question 33

what are the inhibitors and uncouplers of oxidative phosphorylation?

Answer 33

- Inhibitors (of the electron transport chain): CN-, rotenone, CO - Uncouplers: dinitrophenol (DNP), thermogenin which is a protein in brown adipose tissue

Question 34

What is the total ATP production from complete oxidation of 1 molecule of glucose?

Answer 34

30/32 ATP

Question 35

When metabolism takes place in aerobic tissues O2 utilisation results mainly from: A. Its carboxylation to CO2 in the TCA cycle. B. Its reduction to H2O by cytochrome oxidase. C. Its reduction to H2O2 by cytochrome oxidase. D. Its reduction to H2O in the TCA cycle. E. Oxygenation of haemoglobin.

Answer 35

B

Question 36

In the TCA cycle, how many reactions produce NADH + H+ from NAD+?: A. None B. One C. Two D. Three E. Four

Answer 36

D

Question 37

Oxidation of the NADH and FADH2 produced in the TCA cycle occurs: A. in the cytosol. B. on the inner mitochondrial membrane. C. in the mitochondrial intermembrane space. D. in the mitochondrial matrix. E. in the nucleus.

Answer 37

B

Question 38

The electron transport chain is made up of a chain of electron carriers with: A. decreasing electron affinity and decreasing redox potential. B. decreasing electron affinity and increasing redox potential. C. increasing electron affinity and decreasing redox potential. D. increasing electron affinity and equal redox potential. E. increasing electron affinity and increasing redox potential.

Answer 38

E

Question 39

If cells were exposed to an agent that causes the inner mitochondrial membrane to become freely permeable to protons, which of the following effects would you expect to observe? A. Cells would be completely unable to synthesize ATP. B. NADH would build up. C. Carbon dioxide production would cease. D. Consumption of oxygen would fall. E. The ratio of ATP to ADP in the cytosol would fall.

Answer 39

E NOT A BECUASE while ATP synthesis would be impaired, it wouldn't be completely abolished because there are other mechanisms for ATP synthesis, such as substrate-level phosphorylation.

Question 40

what are the 3 main products of the ETC

Answer 40

ATP H2O NAD+ and FAD