BMS07-1027 Fat Storage

Question 1

What are carbohydrates stored as?

Answer 1

Glycogen

Question 2

What is the long term fuel reserve?

Answer 2

Lipids as triglycerides

Question 3

What happens to triglycerides in the fed state?

Answer 3

They are moved from the liver and small intestine to adipose tissue for storage or oxidation in muscles

Question 4

Where does FA synthesis occur?

Answer 4

The liver

Question 5

First step of FA synthesis

Answer 5

Acetyl coenzyme A + carbon dioxide = malonyl coenzyme A using ATP and acetyl coenzyme A carboxylase

Question 6

Which step is rate limiting?

Answer 6

1st

Question 7

What activates the enzyme in the 1st step?

Answer 7

Insulin

Question 8

What does malonyl coenzyme A signify?

Answer 8

Fed state

Question 9

What does malonyl coenzyme A inhibit?

Answer 9

Carnitine transferase so FA cant enter the mitochondria for oxidation

Question 10

Where is fat synthesised?

Answer 10

Cytosol of the liver?

Question 11

How do we get acetyl coenzyme A out of the mitochondria?

Answer 11

Convert this and oxaloacetate to citrate, citrate leaves then converts back to these

Question 12

How are fatty acids synthesised?

Answer 12

Malanyl coenzyme A (this losses its carbon dioxide) + acetyl coenzyme A

It keeps adding malenyl coenzyme A and then loosing a carbon dioxide

Question 13

Which carrier molecule is needed for fatty acid synthesis?

Answer 13

NADPH

Question 14

What is special about fatty acid synthetase?

Answer 14

It is one giant enzymes with all active sites needed for making fatty acids

Question 15

How do you form VLDL?

Answer 15

Add 2 apoproteins to TAG and a polar lipid

Question 16

What are apoproteins?

Answer 16

Proteins that cant function alone

Question 17

What do lipoproteins do?

Answer 17

Transport fat

Question 18

What is the structure of a lipoprotein?

Answer 18

Inside are TAg and cholesterol, outside is a layer of phospholipids, cholesterol and apopproteins

Question 19

What do apoproteins do?

Answer 19

Get recognised by receptors to active lipid metabolising enzymes

Question 20

4 lipoproteins

Answer 20

Chylomicrons
LDL
VLDL
HDL

Question 21

VLDL

Answer 21

TAG

Question 22

LDL

Answer 22

Bad cholesterol to tissues

Question 23

HDL

Answer 23

Cholesterol form tissues to the liver

Question 24

Chylomicrons and what is special about them?

Answer 24

TAG- largest and lowest density

Question 25

How does fat get from the small intestine to the capillary

Answer 25

VLDL attach to an apoprotein and leave small intestine Join to 2 more apoproteins which are attached to HDL This enters the capillary and is then broken down by lipoprotein lipase

Question 26

What activates lipoprotein lipase

Answer 26

Insulin

Question 27

Where do the lipoproteins go from the capillary? (3)

Answer 27

Into adipose to be converted to TAG Into chylomicron then to the liver as it has a receptor for the apoprotein, or to LDL to go in the liver or into peripheral tissues

Question 28

Where does LDL synthesis occur?

Answer 28

In the liver

Question 29

What makes HDL?

Answer 29

Liver and intestine

Question 30

What do LCAT or PACT do?

Answer 30

They are enzymes taking fatty acids and adding it to cholesterol

Question 31

What does cholesterol make?

Answer 31

Bile acids and hormones

Question 32

What does cholesterol do after leaving peripheral tissue? (2)

Answer 32

Apoenzyme is added to form cholesterol ester using LCAT CETP converts it to HDL so it can enter the liver

Question 33

What controls cholesterol synthesis?

Answer 33

Cholesterol

Question 34

What else does cholesterol control?

Answer 34

Number of LDL receptors on the cell surface

Question 35

How is cholesterol formed?

Answer 35

LDL is taken in and converted to lysosomes which release cholesterol by combining with HMG co enzyme A

Question 36

How does LDL affect cholesterol production?

Answer 36

Inhibits it

Question 37

What do statins inhibit?

Answer 37

HMG coenzyme A reductase

Question 38

What does a deficiency of LDL receptors mean?

Answer 38

High blood cholesterol

Question 39

What happens in the statin dose is too high?

Answer 39

Break down muscle fibre

Question 40

Hyperlipidaemias

Answer 40

Lipoprotein disorders

Question 41

What is the condition when there is too much cholesterol?

Answer 41

Hypercholesterolaemia

Question 42

What is the condition when there is too much TAG?

Answer 42

Hypertriglyceridaemia

Question 43

Give some examples of genetic hyperlipoproteinaemias

Answer 43

Defective LDL receptors Lipoprotein lipase deficiency Apoprotein deficiency

Question 44

What causes secondary hyperlipoproteinaemias?

Answer 44

Obesity Type 2 diabetes Alcohol

Question 45

What is associated with coronary heart disease?

Answer 45

Lipoprotein A being in high concentrations as it competes with the thing that breaks down clots

Question 46

What is lipoprotein A?

Answer 46

LDL with apoprotein A

Question 47

What increases and decreases it?

Answer 47

Trans fat | Oestrogen

Question 48

Atherosclerosis

Answer 48

Fatty deposits in arteries (foam cells) filled with cholesterol

Question 49

Describe the receptors of foam cells

Answer 49

Scavengers so they take up lots of oxidised LDL when normal receptors wouldn't