lipid metabolism

Question 1

adipocytes

Answer 1

white adipose cells that can increase their size dramatically

Question 2

where are most fats stored

Answer 2

adipose tissue

Question 3

brown fat

Answer 3

used to generate heat, high concentration of triacylglycerols found, have high content of mitochondria

decouples ETC from ATP synthesis
high amount found in babies

Question 4

epinephrine signaling in lipolysis steps

Answer 4

epinephrine binds to g coupled receptor on cytosol, activating enzymes that convert ATP to cAMP, activating protein kinase A. Triacylglycerol lipase is activated, causing the cleavage of three fatty acids, ultimately forming glycerol that moves to the liver cells

Fatty acids are then oxidized in other tissues

Question 5

Fate of glucose after lipolysis

Answer 5

it is phosphorylated to form glycerol 3 phosphate, which forms DHAP via glycerol phosphate oxidase and G3P dehydrogenase, which releases NADH and forms water as a byproduct.

Question 6

albumin

Answer 6

protein in blood plasma that can deliver fatty acids to cells

Question 7

ibuprofen

Answer 7

hydrophobic molecule delivered by albumin

Question 8

B oxidation

Answer 8

breaks down fatty acid into acetyl CoA, primarily occurs in mitochondria

Question 9

lipoproteins

Answer 9

also carry fatty acids

Question 10

how is fatty acyl coA formed

Answer 10

acyl coa synthase forms fatty acyl CoA through a thioester bond using ATP

required two phosphates (2 ATP)

Question 11

B oxidation in mitochondria

Answer 11

acyl carnitine formed to transport acyl from cytosol to mitochondria, because acyl coa can’t enter on its own

Question 12

carnitine acyl carnitine transferase

Answer 12

anti port that transfers acyl carnitine in exchange for carnitine

Question 13

carnitine Palmitoyl transferase 1/2

Answer 13

1 - cleave acyl to form acyl carinitine
2- cleaves acyl to form acetyl CoA

Question 14

how many carbons are cleaved per cycle to form acetyl CoA?

Answer 14

2 carbons

Question 15

B oxidation first step

Answer 15

acyl coa dehydrogenase forms FADH2 and trans enoyl CoA from Acyl CoA double bond formed

similar to succinate dehydrogenase

Question 16

B oxidations second step

Answer 16

similar to fumarase, hydration by enoyl CoA hydrates forms OH on carbon 2, removing double bond, forming L -3 Hydrxyacyl CoA

Question 17

B oxidation third step

Answer 17

Hydroxyaxyl CoA dehydrogenase forms NADH and 3 ketoacyl CoA turning OH on carbon 2 to carbonyl

oxidation reaction similar to Malate dehydrogenase

Question 18

B oxidation fourth step

Answer 18

thiolase forms acyl CoA and acetyl CoA from 3 ketoacyl CoA,

Acetyl CoA moves on to the citric acid cycle

Question 19

B oxidation fourth step

Answer 19

thiolase forms acyl CoA and acetyl CoA from 3 ketoacyl CoA,

Acetyl CoA moves on to the citric acid cycle

Question 20

how many acetyl CoA molecules are produced from a fatty acid

Answer 20

number of carbons/ 2

Question 21

How many total ATP produced by B oxidation

Answer 21

14

Question 22

How many ATP produced per Acetyl CoA

Answer 22

10

Question 23

how many rounds of B-Oxidation from a fatty acid

Answer 23

(number of carbons/2) -1

Question 24

How much ATP will a 16 carbon fatty acid produce

Answer 24

(8 acetyl CoA * 10 ATP) + (7 rounds * 4 ATP) - 2 ATP cost = 106 ATP

Question 25

how are monosaturated fatty acids cleaved?

Answer 25

Oleoyl CoA cleaves then fatty acid and the cis fatty acid is converted to trans by enoyl CoA isomerase The rest of the oxidation steps are the same.

Question 26

ketone bodies

Answer 26

produced from fatty acids in the liver in low glucose conditions and are converted to acetyl coA, include acetone, acetoacetic acid, and beta hydroxybutyric acid

Question 27

how does brain utilize ketone bodies

Answer 27

it has an enzyme that will convert ketone bodies to acetyl CoA

Question 28

What is true of diabetes patients?

Answer 28

They use fatty acids for energy, and as a result,

Question 29

ketone body/cholestrol biosynthesis

Answer 29

similar processes, isoprene pyrophosphate is a precursor for cholesterol formation.

Question 30

first step of ketone body biosynthesis

Answer 30

B ketothiolase joins two acetyl CoA to form acetoacyl coa

Question 31

second step of ketone body biosynthesis

Answer 31

HMG CoA synthase forms 3 hydroxy-3methylglutaryl CoA

Question 32

third step of ketone body biosynthesis

Answer 32

HMG-CoA lyase generates acetyl CoA and acetoacetate +isoprene pyrophosphate

Question 33

statin drugs

Answer 33

inhibit HMG-CoA Reductase and lower cholesterol, includes Lovastatin

Question 34

What happens after HMG CoA is converted to acetoacetate

Answer 34

it degrades to Acetone and CO2, it can also be converted to B-hydroxybutyrate

Question 35

Why can't the liver utilize ketone bodies as a fuel source?

Answer 35

It doesn't have the enzyme CoA-transferase

Question 36

how does ketoacidosis occur

Answer 36

due to the increase in concentration of ketone bodies due to glucose depletion and fatty acid breakdown, which results in accumulation of H3O+ due to rise in CO2 levels

Question 37

fatty acid synthesis

Answer 37

occurs due to overproduction of acetyl CoA when eating too many carbs, acetyl CoA joins to form fatty acids, which go in cycle with oxidation

Question 38

fatty acid synthesis vs fatty acid oxidation

Answer 38

oxidation happens in the mitochondria, synthesis occurs in the cytosol

Question 39

citrate lyase function

Answer 39

forms Acetyl CoA and oxaloacetate from citrate in high energy conditions

Question 40

formation of malonyl CoA in cytosol

Answer 40

uses ATP, catalyzed by acetyl CoA carboxylase, committed step in fatty acid synthesis

Question 41

how is malonyl coa converted to malonyl acp,

Answer 41

transacylase replaces CoA with ACP on acetyl-CoA and malonyl CoA

Question 42

how are acetyl and malonyl group combined in fatty acid synthesis?

Answer 42

3-ketoacyl ACP synthase catalyzes the reaction

Question 43

reduction of beta carbon ketone,

Answer 43

occurs in presence of NADPH to produce NADP+, requires 3 ketoacyl ACP reductase

Question 44

removal of water in fatty acid synthesis,

Answer 44

done by 3-hydroxyacyl ACP dehydrase, double bond is formed

Question 45

enoyl acp reductase,

Answer 45

reduces double bond in fatty acid synthesis, requires NADPH to form NADP+, fatty acid grows by 2 carbons in each cycle until 16 carbons are reached

Question 46

thioesterase,

Answer 46

releases palmitic acid at end of cycle

Question 47

where are fatty acids longer than 16 carbons made?

Answer 47

endoplasmic reticulum and mitochondria