FA oxidation

Question 1

Solubility of carboxylate group

Answer 1

Hydrophilic

Question 2

Solubility of hydrocarbon chain

Answer 2

Hydrophobic

Question 3

What FA are abundant in food

Answer 3

18 carbon long

Question 4

where does numbering of carbons in FA start

Answer 4

in the carboxyl carbon

Question 5

what are the simpest lipids created from FA

Answer 5

triacylglycerols

Question 6

what is a major form of energy storage

Answer 6

triacylglycerols

Question 7

what links FA to glycerol back bone

Answer 7

ester linkage

Question 8

simple triacyl glycerols

Answer 8

one kind of FA

Question 9

mixed triacylglycerols

Answer 9

more than one type of FA

Question 10

what provides energy and insulation

Answer 10

triacyl glycerols

Question 11

how are triacylglycerols stored

Answer 11

as lipid droplets in adipocytes/ fat cells

Question 12

advantages of using triacylglycerols over glucose

Answer 12

carbons more reduced= higher potential for oxidation and yield more energy

hydrophobic and unhydrated so they dont weight much like polysaccharides

Question 13

sources of triacylglycerols

Answer 13

– fats consumed in the diet
– fats stored in cells as lipid droplets
– fats synthesized in one organ for
export to another
– fats obtained by autophagy

Question 14

what emulsify FA and where

Answer 14

bile salts in the small intestine

Question 15

what do bile salts convert

Answer 15

insoluble
macroscopic fat particles to finely
dispersed microscopic micelles

Question 16

what degrades triacyl glycerols

Answer 16

lipases- converts to monoacylglycerols
(monoglycerides) and
diacylglycerols (diglycerides) and
free fatty acids

Question 17

what happens to mono and diglycerides and free FA

Answer 17

Products transported into
intestinal mucosa (epithelial cells
lining intestinal surface)

Question 18

what happens once Products transported into
intestinal mucosa (epithelial cells
lining intestinal surface)

Answer 18

Reconverted into triacylglycerols
○ and packaged into lipoprotein
aggregates

Question 19

where are lipoprotein aggregates carried to in the blood

Answer 19

to muscle and adipose tissue

Question 20

what happens when lipoprotein aggregates reach the muscle and adipose tissue

Answer 20

Triacylglycerols hydrolyzed by
lipoprotein lipase into free fatty acids
and monoacylglycerols

Question 21

what happens to products hydrolyzed by lipoprotein lipase

Answer 21

transported
across cell membrane

Question 22

what happens when lipased FA are transported across cell membrane

Answer 22

Fatty acids oxidized for energy or
stored as triacylglycerols

Question 23

how much energy does oxidatoin of FA provide for energetic needs in heart & liver

Answer 23

up to 80%

Question 24

how much energy does FA oxidation provide for daily energy requirement

Answer 24

40%

Question 25

Isozyme in the outer mitochondrial membrane

Answer 25

Fatty Acyl-CoA Synthetase

Question 26

how does Fatty Acyl-CoA Synthetase work

Answer 26

* Activates fatty acids by adding CoA – converts them into fatty acyl-CoA thioesters

Question 27

what kind of linkage is created bw FA and coenzyme A

Answer 27

* Creates thioester linkage between the fatty acid carboxyl group and the thiol group of coenzyme A

Question 28

what makes high energy thioester bond favourable

Answer 28

– high energy bond made possible (favorable) by hydrolysis of two ATP bond from PPi

Question 29

where are activated FA transported

Answer 29

into mitochondria

Question 30

what size of FA can diffuse freely across mitochondrial membranes

Answer 30

Small (< 12 carbons)

Question 31

how are Long-chain fatty acids (containing 14+ carbons) transported across cell membrane

Answer 31

are transported through a carnitine shuttle – must be activated to a fatty acyl-CoA – must be attached to carnitine

Question 32

transiently attaches fatty acyl-CoA to carnitine

Answer 32

* CAT1

Question 33

allows passive transport of fatty acyl-carnitine ester

Answer 33

Acyl-Carnitine/Carnitine cotransporter

Question 34

regenerates fatty acyl-CoA and frees carnitine

Answer 34

CAT2

Question 35

* Acyl-CoA in mitochondrial matrix

Answer 35

can be used for oxidation and ATP production – conversion to the carnitine ester commits it to oxidation – carnitine-mediated entry is the rate-limiting step for oxidation of fatty acids in mitochondria

Question 36

Acyl-CoA in cytosol

Answer 36

can be used for membrane lipid synthesis – the first intermediate in fatty acid synthesis (Malonyl-CoA) inhibits CAT1, assuring that fatty acid oxidation and synthesis do not occur simultaneously

Question 37

Two Pools of Fatty Acyl-CoA

Answer 37

Acyl-CoA in mitochondrial matrix Acyl-CoA in cytoso

Question 38

Stage 1 of Fatty Acid Oxidation

Answer 38

β oxidation – fatty acids undergo oxidative removal of successive two-carbon units in the form of acetyl-CoA

Question 39

Stage 2 of Fatty Acid Oxidation

Answer 39

* Oxidation of acetyl-CoA groups to CO2 in the Citric Acid Cycle – occurs in the mitochondrial matrix – generates NADH, FADH2 , and one GTP

Question 40

Stage 3 of Fatty Acid Oxidation

Answer 40

* Electron Transport Chain and oxidative phosphorylation – generates ATP from NADH and FADH2

Question 41

Stage 1: oxidation four main steps

Answer 41

1. oxidation 2. hydration 3. oxidation 4. cleavage