Fatty Acid Metabolism & Photosynthesis

Question 1

Anaerobic respiration occurs under what conditions?

Answer 1

When there is no oxygen available

Question 2

How much ATP is generated by anaerobic respiration per glucose?

Answer 2

2 ATP molecules

Question 3

In humans, anaerobic respiration stops at the end of glycolysis. What does the pyruvate get converted to?

Answer 3

Lactate

Question 4

What is the Pasteur effect?

Answer 4

When after undergoing anaerobic respiration, replenishing the system with oxygen allows the cells to return to oxidative phosphorylation

Question 5

Do healthy tissues or tumour tissues use more glucose?

Answer 5

Tumours use more glucose

Question 6

What is the Warburg effect?

Answer 6

The Warburg effect is defined as an increase in the rate of glucose uptake and a preferential lactate production, regardless of whether oxygen is present

Question 7

Why do tumours prefer to make most of their ATP by aerobic glycolysis?

Answer 7

They can produce ATP faster, although much less efficiently

Question 8

Tumours have an increased secretion of lactate as they prefer aerobic glycolysis. How does this affect the surrounding tissues’ pH?

Answer 8

It lowers the pH, making it more acidic

Question 9

The reverse Warburg effect allows cancer cells to induce aerobic glycolysis in surrounding stromal fibroblasts. Why do they do this?

Answer 9

So that the fibroblasts secrete lactate, which is then taken up, oxidised, and used as a fuel by the cancer cells

Question 10

Fatty acids can be metabolised and fed into the respiration pathway. What fatty acid is mainly used?

Answer 10

Triglycerides

Question 11

What type of enzyme breaks the triacylglycerides down?

Answer 11

Lipase

Question 12

Triacylglycerides are broken down into what two components?

Answer 12

3 fatty acids and 1 glycerol

Question 13

The glycerol from a triacylglyceride is fed into glycolysis. What is it converted into?

Answer 13

Pyruvate

Question 14

Which yield more energy during respiration - glucose or a fatty acid?

Answer 14

Fatty acids are more energy dense than glucose

Question 15

Fatty acids are broken down into 2C units before they are converted into Acetyl CoA. How much ATP is produced per 2C unit?

Answer 15

12 ATP per 2C unit

Question 16

If an 18C fatty acid is broken down, how much ATP will it produce?

Answer 16

Nine 2C units = 9 X 12 = 108 ATP

Question 17

How many carbons make up hexose?

Answer 17

Six

Question 18

Is photosynthesis a catabolic or anabolic pathway?

Answer 18

Anabolic

Question 19

What are the two reactions that make up photosynthesis?

Answer 19

The light and the dark reactions

Question 20

The section of a chlorophyll molecule that locates it to the thylakoid membrane is the…?

Answer 20

Phytol tail

Question 21

What are phytol tails?

Answer 21

They are hydrophobic tails attached to chlorophyll that allow anchoring to thylakoid membranes. They allow for the localisation of chlorophyll in the correct place

Question 22

What colour wavelength of light does chlorophyll a NOT absorb?

Answer 22

Green

Question 23

What are the two light reactions?

Answer 23

Photosystem I and photosystem II

Question 24

What is the dark reaction called?

Answer 24

The Calvin cycle

Question 25

What does the light reaction of photosynthesis do?

Answer 25

Transforms light into O2, ATP, and NADPH

Question 26

What does the dark reaction of photosynthesis do?

Answer 26

Uses ATP and NADPH to reduce CO2 to a more reduced state, which can serve as a carbon fuel

Question 27

What are the three stages of the Calvin cycle?

Answer 27

1. Fixation
2. Reduction
3. Regeneration of acceptor

Question 28

How many turns of the Calvin cycle are needed to be able to generate enough carbons to make one glucose molecule?

Answer 28

Two turns

Question 29

How many molecules of CO2 are produced per one turn of the Calvin cycle?

Answer 29

Three CO2 molecules

Question 30

How many molecules of ATP does each turn of the Calvin cycle use up?

Answer 30

9 ATP

Question 31

When a cancer cell utilises the Warburg effect, what cofactor is recycled and hence made available for further use in glycolysis?

Answer 31

NAD