L30 Fat Metabolism

Question 1

Fat is stored in…

Answer 1

White adipose tissue

Question 2

Fat is stored as…

Answer 2

Triglycerides

Question 3

Fat cells are known as…

Answer 3

Adipocytes

Question 4

Adipocytes contain an expandable…

Answer 4

Fat reservoir

Question 5

Other than energy storage, fats are also used in the body as (3)…

Answer 5

Thermal insulation
Electrical insulation
Cell structural support

Question 6

Cholesterol…

a) cannot be recycled by the liver, must be metabolised by the body
b) cannot be metabolised or recycled
c) cannot be metabolised by the body, except the kidney
d) cannot be metabolised by the body, must be recycled by the liver

Answer 6

d) cannot be metabolised by the body, must be recycled by the liver

Question 7

Fat is a very efficient energy source. A 70kg person has on average enough fat to supply energy for…

Answer 7

2 months

Question 8

Most naturally occurring triglycerides are…

Answer 8

Cis (with H on the same side of C=C double bond)

Question 9

Saturated triglycerides shape

Answer 9

Linear

Question 10

Unsaturated fats shape

Answer 10

Kinked

Question 11

Fat metabolism has 3 stages…

Answer 11

1. Lipolysis
2. Activation of fatty acids
3. Oxidation of fatty acids

Question 12

Step 1 of fat metabolism, lipolysis, is mediated by…

Answer 12

Hormones

Question 13

Lipolysis occurs under conditions of..,.

Answer 13

Starvation, stress or exercise

Question 14

Lipase breaks which bonds in triglycerides?

Answer 14

Ester bonds

Question 15

Lipase catalyses the conversion of triglycerides into…

Answer 15

Glycerol and fatty acids

Question 16

Glycerol from lipolysis moves to the…

Answer 16

Liver

Question 17

Glycerol is processed in the liver and converted to G-3-P, which can be used in…

Answer 17

Gluconeogenesis or citric acid cycle (if converted to pyruvate)

Question 18

In fatty acid activation, fatty acids from lipolysis enter the…

Answer 18

Cytoplasm

Question 19

Step 2 of fat metabolism is…

Answer 19

Fatty acid activation

Question 20

Fatty acid is activated by addition of…

Answer 20

CoA

Forming Acyl CoA

Question 21

Energy for fatty acid activation comes from…

Answer 21

Hydrolysis of ATP to AMP + PPi

Question 22

The acyl group is needed inside the mitochondria, however acyl CoA cannot cross the membrane, thus it is added to…

Answer 22

Carnitine, forming acyl carnitine

Question 23

Step 3 of fat metabolism is…

Answer 23

Beta oxidation

Hydrogen is removed from the beta carbon

Question 24

Beta oxidation occurs over 4 steps…

Answer 24

1. Oxidation I (FAD)
2. Hydration
3. Oxidation II (NAD+)
4. Cleavage (acylation)

Question 25

Products of beta oxidation are...

Answer 25

8 acetyl CoA 7 FADH2 7 NADH and H+

Question 26

High energy yield compared to glucose. For example C16 (Palmitic acid) yields ...

Answer 26

108 ATP | versus 32 for glucose

Question 27

In the absence of glucose, glycolysis is...

Answer 27

Switched off

Question 28

In the absence of glucose, citric acid cycle intermediates...

Answer 28

Enter gluconeogenesis to maintain blood glucose homeostasis

Question 29

In ketone metabolism, acetyl CoA is converted to...

Answer 29

Ketone bodies in the liver

Question 30

Lipogenesis occurs during...

Answer 30

High energy conditions | Lots of glucose, high acetyl CoA, high citrate

Question 31

The lipogenesis pathway is increased by (2)...

Answer 31

High citrate and insulin

Question 32

Lipogenesis pathway is decreased by (4)...

Answer 32

High AMP, glucagon, Adrenalin or palmitoyl

Question 33

The decrease in lipogenesis caused by high palmitoyl is an example of...

Answer 33

Negative feedback

Question 34

Glycerol is recycled in the liver to produce...

Answer 34

Glucose (gluconeogenesis)

Question 35

Energy is released from fatty acids by...

Answer 35

Beta oxidation

Question 36

Beta oxidation can be summarised as (4)...

Answer 36

Oxidation, hydration, oxidation, cleavage

Question 37

Lipogenesis is the opposite of...

Answer 37

Lipolysis

Question 38

They key enzyme controlling fatty acid synthesis is...

Answer 38

Acetyl CoA carboxylase

Question 39

Insulin is a major regulator of lipogenesis in...

Answer 39

Type 2 diabetes

Question 40

Ketone bodies are generated from fatty acid metabolism under which 2 conditions?

Answer 40

Prolonged starvation (or lack of glucose) Type 1 diabetes

Question 41

In type 1 diabetes, excessive ketone bodies in the blood can decrease pH dangerously resulting in...

Answer 41

Ketoacidosis