Exam 3 Lipid Metabolism I part b

Question 1

elongation happens where?

Answer 1

smooth endoplasmic reticulum (SER) or mitochondria

Question 2

FA are lengthened _ carbons at a time

Answer 2

2 carbons

Question 3

what is the enzyme for elongation

Answer 3

FA elongase

Question 4

SER pathway uses _ as carbon donor

Answer 4

malonyl coA

Question 5

mitochondria uses _ as a carbon donor

Answer 5

acetyl coA

Question 6

desaturation =? And occur in SER, use NADPH/NADH, and oxygen catalyzed by _

Answer 6

Desaturation = introduction of double bonds; acyl coA desaturases

Question 7

T/F: FA with double bond beyond carbon 9 and 10 cannot be synthesized in humans

Answer 7

true eg omega 3 FAs and omega 6 FAs (beyond carbon 9)

Question 8

precursors for omega 3/6 FAs are called

Answer 8

essential FAs

Question 9

_ acid is used to make arachidonic acid

Answer 9

linoleic acid

Question 10

_ acid used to make eicosapentanoic acid and docosahexanoic acid

Answer 10

linolenic acid

Question 11

DHA is important for the development of _

Answer 11

brain

Question 12

when FAs are in excess, they are incorporated into

Answer 12

TAGs (storage form of lipids)

Question 13

100,000 kcal in TAGs are stored in

Answer 13

fat and muscle

Question 14

what are the 3 locations TAGs are built

Answer 14

1. dietary TAG processed in intestinal
2. de nevo TAG in hepatocytes
3. de novo TAG in adipocytes

Question 15

T/D: TAG synthesis in the liver has a carbohydrate arm and a FA arm

Answer 15

true

Question 16

TAG synthesis in the liver use _ and _ to form G3P

Answer 16

glucose and glycerol (carbohydrate arm)

Question 17

_ used as backbone for TAG synthesis

Answer 17

G3P

Question 18

Fatty acyl coA synthetase does what?

Answer 18

activates FAs by adding coA to FAs

Question 19

FFA in TAG synthesis in the liver come from:

Answer 19

synthesized in liver from acetyl coA added to G3P to form TAGs in the liver

Question 20

TAGs packaged with apolipoproteins and other lipids to form a lipoprotein called _

Answer 20

VLDL

Question 21

VLDLs are released into _

Answer 21

bloodstream

Question 22

TAG synthesis in hepatocytes promoted by excess _

Answer 22

carbohydrates

Question 23

G3P -> _ (1 FA, 1 OH, 1 OPO4), -> _ (2 FA, 1 OPO4) -> DAG -> TAG

Answer 23

G3P -> Lysophosphatidic acid -> phosphatidic acid

Question 24

extra glucose in the blood form _ which is the backbone for TAG. In adipocytes there is not direct _ because…

Answer 24

Form G3P; in adipocytes there is no direct phosphorylation of glyercol to G3P bc glycerol kinase is absent in adipocytes

Question 25

capillary lipoprotein lipase works to do what?

Answer 25

chips off FAs from chylomicrons and VLDLs and transport into cell

Question 26

How do we accomplish TAG synthesis in adipocytes

Answer 26

liver makes TAGs and packages into VLDLs and release into blood; this is how we have TAG synthesis in adipocytes

Question 27

FFA in TAG synthesis in adipocytes come from:

Answer 27

from breakdown of chylomicrons and VLDL in blood by the action of capillary lipoprotein lipase

Question 28

G3P and FFA form

Answer 28

TAGs

Question 29

TAG synthesis in adipocytes promoted by:

Answer 29

excess carbohydrate and fats

Question 30

what is the biggest difference between TAG synthesis in liver vs adipocytes?

Answer 30

the source of FAs. In liver FAs synthesized w/in the liver vs adipocytes where FAs are obtained from the breakdown of chylomicrons and VLDLs.

Question 31

TAGs are released from the liver in the form of _ but in adipocytes the TAGs are _ in the cells

Answer 31

form of VLDLs and in adipocytes the TAGs are retained in the cells