Lipid Catabolism and Ketone body synthesis

Question 1

enzyme that breaks down TAGs into free FA and glycerol in adipose tissue

Answer 1

hormone sensitive lipase

Question 2

inhibits HS lipase in adipose tissue

Answer 2

insulin

Question 3

stimulates HS lipase in adipose tissue

Answer 3

epinephrine or low insulin levels

Question 4

activates FA into FA acyl CoA

Answer 4

thiokinase

Question 5

where is thiokinase located

Answer 5

outer mitochondrial membrane

Question 6

step that needs 2 ATP

Answer 6

FA into FA acyl CoA via thiokinase

Question 7

how does acyl CoA traverse through the inner mitochondrial membrane

Answer 7

binds to carnitine to form carnitine acyl CoA via CPT-1, then transported across the membrane via translocase

Question 8

inhibitor of CPT-1

Answer 8

malonyl CoA

Question 9

removes carnitine from acyl CoA after its in the mitochondrial matrix

Answer 9

CPT-II

Question 10

formula for beta oxidation cycles

Answer 10

of carbons, divided by 2. subtract 1 from answer

Question 11

most common enzyme deficiency associated with b-oxidation

Answer 11

MCAD (acyl CoA dehydrogenase)

Question 12

carbon length during b-oxidation when MCAD takes over

Answer 12

10 carbons

Question 13

carbon length during b-oxidation when SCAD takes over

Answer 13

6 carbons

Question 14

1 acetyl CoA gives you how many ATP from krebs

Answer 14

12

Question 15

systemic b-oxidaton disorder presents with

Answer 15

hypoglycemia & hypoketosis

Question 16

enzymes that can be involved in systemic b-oxidaton disorders

Answer 16

MCAD, CPT-1, systemic carnitine

Question 17

what is jamaican vomiting sickness

Answer 17

ingestion of unripe ackee fruit leads to systemic b-oxidation disorder. the fruit contains hypoglycin A that inhibits MCAD

Question 18

produced in the final round of odd chain b-oxidation

Answer 18

propionyl CoA

Question 19

propionyl CoA to methylmalonyl CoA requires

Answer 19

propionyl CoA carboxylase and biotin

Question 20

methylmalonyl CoA to Succinyl CoA requires

Answer 20

methylmalonyl mutase and B12 (Cobalamin)

Question 21

Very Long Chain FA (more than 20 carbons) are oxidized where

Answer 21

perioxisomes

Question 22

defective peroxisomal biogenesis primarily affecting liver and brain. presents with extensive demyelination, neurological defects, hepatomegaly, and hepatocellular failure.

Answer 22

zellweger syndrome

Question 23

what is alpha oxidation.

Answer 23

oxidation of branched FA that occurs in perioxisomes

Question 24

refsum disease is a defect of which enzyme

Answer 24

perioximal phytanyl CoA hydroxylase (alpha oxidation)

Question 25

type of oxidation that forms dicarboxylic acids

Answer 25

omega oxidation

Question 26

ketogenesis takes place where

Answer 26

liver mitochondria

Question 27

name 3 ketone bodies

Answer 27

acetoacetate, 3-hydroxybutyrate, acetone

Question 28

steps from acetyl CoA to first ketone body

Answer 28

2 Acetyl CoA’s to Acetylacyl CoA via thiolase, Acetylacyl Coa to HMG CoA via HMG CoA synthase, HMG CoA to acetoacetate via HMG CoA lyase

Question 29

major ketone body is formed from

Answer 29

acetoacetate and NADH. (3-hydroxybutyrate)

Question 30

ketone body formed spontaneously

Answer 30

acetone. (cannot be utilized by peripheral tissues)

Question 31

does the brain utilize FA’s or ketone bodies or both?

Answer 31

ketone bodies

Question 32

acetoacetate is activated into acetoacyl CoA by

Answer 32

succinyl CoA:acetoacetate CoA transferase (thiophorase).

this enzyme isn’t present in the liver. liver can’t utilize ketone bodies

Question 33

brain shifts to using ketone bodies after how many days of starvation

Answer 33

3

Question 34

metabolic disorder associated with diabetes melitus

Answer 34

metabolic acidosis