Lipid Metabolism Flashcards Preview

HMS Chemical Biology and Biochemistry > Lipid Metabolism > Flashcards

Flashcards in Lipid Metabolism Deck (41)
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1

PPARs

nuclear hormone receptors which bind directly to hormones which diffuse into the nucleus, then change conformation and initiate transcription.

2

Saturated fatty acids can bind to some PPARs and thereby increase the expression of genes involved in. . .

Saturated fatty acids can bind to some PPARs and thereby increase the expression of genes involved in cholesterol and fat synthesis.

3

Unsaturated fatty acids can bind to some PPARs and thereby increase the expression of genes involved in. . .

breakdown of fat and repression of fat and cholesterol synthesis.

4

Diets that include high amounts of ___ and ___ may promote fat synthesis

Diets that include high amounts of saturated and trans fats may promote fat synthesis, which can lead to insulin resistance and cardiovascular disease.

5

The rate-limiting step of fatty acid synthesis

Acetyl-CoA carboxylase

6

The fatty acids produced in lipogenesis will be packaged into triglycerides and exported from the liver in the form of ___.

The fatty acids produced in lipogenesis will be packaged into triglycerides and exported from the liver in the form of VLDL.

7

β-oxidation provides. . .

Acetyl-CoA

NADH

FADH2

8

______ are more atherogenic (lead to formarmation of plaques in arteries) than cholesterol itself.

Saturated fats and trans fats are more atherogenic (lead to formarmation of plaques in arteries) than cholesterol itself.

9

Palmitate and Stearate

10

"Essential" fatty acids

Linoleic acid and α-linolenic acid

11

Humans do not have the machinery to introduce ____ into oleic acid.

Humans do not have the machinery to introduce the second double bond into oleic acid.

 

We therefore need to get polyunsaturated fats in the diet.

12

Important α-linolenic acid derivatives

EPA and DHA

13

Linoleic acid

14

α-linolenic acid

15

In the fed state, excess glucose is. . .

. . . converted into fat by the liver and sent to adipose tissue for storage.

16

Acetyl-CoA traverses the mitochondrial membrane in the form of. . .

citrate

17

For efficient synthesis of fatty acids from glucose, ____ are required.

For efficient synthesis of fatty acids from glucose, mitochondria are required.

 

This is for two reasons:  1.  PDH is only present in the mitochondrial matrix, and 2.  the main source of Acetyl-CoA for fatty acid synthesis comes from citrate which traverses the mitochondrial membrane.

18

Acetyl-CoA Carboxylase mechanism

19

Malonyl CoA inhibits. . .

beta oxidation

 

This ensures that lipogenesis and lipolysis are not occuring simultaneously.

20

Regulation of Acetyl-CoA Carboxylase

21

Fatty acid biosynthesis mechanism

22

Reaction catalyzed by hormone sensitive lipase

Hydrolysis of the first of the three acyl chains on a triacylglyceride, producing one fatty acid and a diacylglyceride.

23

Hormone sensitive lipase regulation

24

Perlipin

Protein on the adipocyte lipid droplet membrane which, when activated by glucagon -> PKA phosphorylation, enables hormone sensitive lipase to access lipid droplets.

25

Charging of fatty acids prior to the beginning of β-oxidation

26

Rate limiting step for β-oxidation

Movement of fatty acids to the mitochondrial matrix

27

Carnatine transport

28

Regulatory role of malonyl CoA

29

β-oxidation mechanism

30

Comparing products of glucose and fatty acid metabolism