Fatty Acids

Question 1

Where does FA synt. Occurs?

Answer 1

Cytosol

Question 2

What are the cofactors needed for FA synt?

Answer 2

NADPH, ATP, HCO3-, Biotin

Question 3

Substrate and products of FA synt

Answer 3

Acetyl co A -> palmitate

Question 4

What is required for the first step of FA synt? Enzyme?

Answer 4

Bicarbonate

Acetyl coA carboxylase

Question 5

What are the two steps of the carboxylation of acetyl coA?

Answer 5

1) carboxylation of biotin

2) transfer of carboxyl group to acetyl coA to form malonyl coA

Question 6

Where can we obtain NADPH from?

Answer 6

1) PPP

2) malate -> pyruvate (malic enzyme)

Question 7

What enzyme catalyzes this reaction

Citrate -> acetyl coA + OAA

Answer 7

ATP citrate lyase

Question 8

What enzyme in FA oxidation uses NAD+

Answer 8

3- hydroxy acyl coA DH

Question 9

What enzyme in FA oxidation uses FAD

Answer 9

Acyl coA DH

Question 10

what is the action of hormone sensitive lipase?

Answer 10

degrade TAG in adipose tissue

Question 11

waht inhibits hormone sensitive lipase?

Answer 11

insulin

Question 12

describe the structure of a Lipoprotein? whats inside? whats outside?

Answer 12

non polar core- TAG and cholesterol esters

surrounded by- phospholipids, cholesterol, apoproteins

Question 13

what is the source of-
chylo
chylo renants
VLDL
IDL
LDL
HDL

Answer 13

intestines -> chylo
chylomicrons -> chylo renants
liver/intestine -> VLDL
VLDL -> IDL
VLDL -> LDL
liver/intestine/VLDL/chylomicrons -> HDL

Question 14

what apo recognize LDL receptor?

Answer 14

Apo B-100

Apo E

Question 15

how does LDL contributes to the process of artherosclerosis?

Answer 15

if they become oxidized within the walls of arteries.

Question 16

when do LDL particles are formed?

Answer 16

as VLDL lose triglyceride through the action of lipoprotein lipase (LPL) and they become smaller and denser
they now contain higher number of cholesterol ester

Question 17

write down the enzymes of B oxidation by order

Answer 17

Acyl coA DH (produces FADH2)
enoyl coA hydratase
3-hydroxyacyl coA DH (produces NADH+H)
B ketoacyl coA thiolase

Question 18

write down the enzymes of FA synthesis by order

Answer 18

3-ketoacyl-ACP synthase
3-ketoacyl-ACP reductase (uses NADPH)
3-Hydroxyacyl ACP dehydrase
Enoyl-ACP reductase (uses NADPH)

Question 19

write down the enzymes of ketone bodies synthesis by order

Answer 19

thiolase (2xacetyl coA forms acetoacetyl co A)
HMG coA synthase
HMG coA lyase
B-HB DH (acetoacetate forms B-HB and NAD+)