Fatty acid oxidation Flashcards Preview

Biochem > Fatty acid oxidation > Flashcards

Flashcards in Fatty acid oxidation Deck (30):
1

What type of fatty acid cannot enter the mitochondria?

Long chain fatty acid

2

How do medium and short chain fatty acids enter the mitochondria?

simple diffusion

3

How are fatty acids actiated in the mitochondria?

transformed into Acyl-CoAs

4

Carnitine transport system

Transports acyl-CoAs across the inner mitochondria membrane by turning into acylcarnitine (CPT1) then transferring back to carnitine (CPT2)

5

What does beta-oxidation produce?

1 Acetyl-CoA, 1 FADH2, 1 NADH, an acyl-CoA reduced by 2 carbons

6

Acyl-CoA DH

Makes FADH2 (1st step beta oxidation)

7

Enoyl-CoA hydratase

Adds H2O

8

3HCoADH

makes NADH (3rd step beta oxidation)

9

beta-ketothiolase

Adds HSCoA to make Acetyl Co-A and acyl-CoA

10

How many ATP are formed from FADH2?

2

11

How many ATP are formed from NADH?

3

12

Very long chain acyl-CoA DH prefers how many carbon?

12 to 24

13

Long-chain acyl CoA DH prefers how many carbons?

12 to 16

14

Medium chain Acyl-CoA DH prefers how many carbons?

6 to 8

15

Short chain acyl-CoA DH prefers how many carbons?

4>6>8

16

What inhibits CPT 1?

Malonyl-CoA

17

What happens to beta oxidation when insulin predominates?

Acety-CoA carboxylase is stimulated, Malonyl-CoA concentration increased, so fatty acid synthesis is stimulated while beta-oxidation is inhibited

18

What happens to beta oxidation when glucaogon predominates?

Acetyl-CoA carboxylase is inhibited, Malonyl-CoA concentrations decrease. Inhibition of CPT 1 is relieved.

19

What happens to the product of odd-numbered fatty acid beta oxidation?

propionyl-CoA is converted to succinyl-CoA, which can be used in gluconeogenisis

20

Where does the oxidation of very long chain fatty acids occur?

peroxisomes

21

What is unquie about the modified oxidation in peroxisomes?

oxidation is not linked to cofactor reduction

22

Omega oxidation

Occurs in the ER. Utilizes Cytochrome P450. Is the detox rxn in humands. Produces a dicaroxylic acid

23

What are the 3 ketone bodies?

Acetoacetate, Acetone, beta-hydroxybutyrate

24

HMG-CoA synthase and lysase

Produce only ketone bodies in the liver mitochondria

25

What is the only place ketone synthesis enzymes can be found?

only liver mitochondria

26

What causes the fruity breath in keto-acidosis?

Acetone

27

Medium chain acyl-CoA deficiency

Most common genetic disease of lipid metabolism. Causes non-ketotic hypoglycemia, fatty infiltration of liver, short chain dicarboxylic acids can be found in the urine

28

Carnitine deficiency

Insufficient fatty acid delivery to mitochondria. Causes non-ketotic deficiency. Can treat with oral carnitine

29

CPT I deficiency

LCFA can go into the mitochondria. Hepatomegaly with fatty infiltration. Causes increased plasma carnitine levels. Can be overcome with MCFA

30

Refsum disease

Deficiency in a component of branched-chain oxidation. Serious neurological deficiency. Reduce phytanic acid in diet.