Lipid Metabolism Part II Lipoprotein Metabolism

Question 1

what is mean by postabsorptive state?

Answer 1

means fatty acids can be released from adipose tissue to be used for energy.

Question 2

The fall in insulin activates a ____________ that hydrolyzes triglycerides, yielding ______________.

Answer 2

hormone-sensitive triacylglycerol lipase (HSL) ,
fatty acids and glycerol.

Question 3

Epinephrine and cortisol. also _____________.

Answer 3

activate HSL .

Question 4

Free fatty acids are transported through the blood in association with___________

Answer 4

serum albumin.

Question 5

what will be picked up by liver and converted to what for gluconeogenesis?

Answer 5

Glycerol may be picked by liver, converted to dihydroxyacetone phosphate (DHAP)

Question 6

fatty acids are oxidized into tissues including what and by which pathway?

Answer 6

liver, muscle, and adipose tissue, by β-oxidation pathway.

Question 7

What can NOT use fatty acids and so continue to rely on glucose during what time?

Answer 7

Erythrocytes and brain, during normal periods of fasting.

Question 8

Erythrocytes lack ____________, and fatty acids do not cross the______________ efficiently.

Answer 8

mitochondria, blood–brain barrier.

Question 9

what all diffuse freely into mitochondria to be oxidized.

Answer 9

short-chain fatty acids and medium-chain fatty acids.

Question 10

long-chain fatty acids must be ____________& transported into the mitochondrion by a _______________ to be oxidized.

Answer 10

activated, carnitine shuttle

Question 11

very long-chain fatty acids enter _______________
via an unknown mechanism for oxidation.

Answer 11

enter peroxisomes

Question 12

_____________on the outer mitochondrial membrane, activates the fatty acids by attaching CoA.

Answer 12

Fatty acyl-CoA synthetase

Question 13

The fatty acyl portion is then transferred onto carnitine by _________________for transport into the mitochondria.

Answer 13

carnitine acyltransferase-1 (CAT-1).

Question 14

what is shuttled across the inner membrane.

Answer 14

Fatty acylcarnitine

Question 15

Carnitine acyltransferase-2 (CAT-2)/ carnitine palmitoyl transferase-2 (CPT-2) transfers the ______________ back to ___________.

Answer 15

fatty acyl group, a CoA .

Question 16

Carnitine acyltransferase-1 is inhibited by _____________.

Answer 16

malonyl-CoA .

Question 17

Carnitine acyltransferase-1 prevents newly synthesized fatty acids from entering the ______________.

Answer 17

mitochondria.

Question 18

Insulin indirectly inhibits β-oxidation by activating ____________ and increasing the ____________ concentration in the cytoplasm which inhibits_____________.

Answer 18

acetyl-CoA carboxylase, malonyl-CoA, Carnitine acyltransferase.

Question 19

Carnitine acyltransferase-1 and -2 (CAT-1 and CAT-2) are also called as?

Answer 19

carnitine palmitoyl transferase-1 and -2 (CPT-1 and CPT-2).

Question 20

what reverses the process of fatty acid synthesis by oxidizing?

Answer 20

β-oxidation.

Question 21

β-oxidation after oxidizing it releases units of _______________ and what is the pathway of it?

Answer 21

acetyl-CoA, repetition of 4 steps.

Question 22

Each 4-step cycle releases one _________and reduces NAD and FAD producing___________.

Answer 22

acetyl-CoA, NADH and FADH2

Question 23

FADH2 and NADH are oxidized in the __________ providing ATP.

Answer 23

electron transport chain.

Question 24

what cycle does muscle and adipose tissue, the acetyl-CoA enters to?

Answer 24

citric acid cycle.

Question 25

in liver ATP used for what?

Answer 25

Gluconeogenesis.

Question 26

By activating what does acetyl-CoA stimulates gluconeogenesis?

Answer 26

Pyruvate carboxylase.

Question 27

In a ___________ state, the liver produces more acetyl-CoA from β-oxidation than is used in the citric acid cycle

Answer 27

fasting state

Question 28

the acetyl-CoA is used to synthesize __________ that are released into the blood for other tissues.

Answer 28

ketone bodies.

Question 29

What are the two most common genetic deficiencies affecting fatty acids oxidation ?

Answer 29

1.Medium chain acyl-CoA dehydrogenase (MCAD) deficiency. (it’s in liver.)
2.Myopathic carnitine acyltransferase (CAT/CPT) deficiency. (it’s in muscle.)

Question 30

In MCAD______________ should be strongly associated with a block in hepatic β-oxidation.

Answer 30

Non-ketortic hypoglycemia .

Question 31

In MCAD______________ should be strongly associated with a block in hepatic β-oxidation.

Answer 31

Non-ketortic hypoglycemia.

Question 32

At what period hypoglycemia can become profound due to lack of ATP to support gluconeogenesis.

Answer 32

During fasting.