Exam 3 Lipid Metabolism I part b Flashcards
elongation happens where?
smooth endoplasmic reticulum (SER) or mitochondria
FA are lengthened _ carbons at a time
2 carbons
what is the enzyme for elongation
FA elongase
SER pathway uses _ as carbon donor
malonyl coA
mitochondria uses _ as a carbon donor
acetyl coA
desaturation =? And occur in SER, use NADPH/NADH, and oxygen catalyzed by _
Desaturation = introduction of double bonds; acyl coA desaturases
T/F: FA with double bond beyond carbon 9 and 10 cannot be synthesized in humans
true eg omega 3 FAs and omega 6 FAs (beyond carbon 9)
precursors for omega 3/6 FAs are called
essential FAs
_ acid is used to make arachidonic acid
linoleic acid
_ acid used to make eicosapentanoic acid and docosahexanoic acid
linolenic acid
DHA is important for the development of _
brain
when FAs are in excess, they are incorporated into
TAGs (storage form of lipids)
100,000 kcal in TAGs are stored in
fat and muscle
what are the 3 locations TAGs are built
- dietary TAG processed in intestinal
- de nevo TAG in hepatocytes
- de novo TAG in adipocytes
T/D: TAG synthesis in the liver has a carbohydrate arm and a FA arm
true
TAG synthesis in the liver use _ and _ to form G3P
glucose and glycerol (carbohydrate arm)
_ used as backbone for TAG synthesis
G3P
Fatty acyl coA synthetase does what?
activates FAs by adding coA to FAs
FFA in TAG synthesis in the liver come from:
synthesized in liver from acetyl coA added to G3P to form TAGs in the liver
TAGs packaged with apolipoproteins and other lipids to form a lipoprotein called _
VLDL
VLDLs are released into _
bloodstream
TAG synthesis in hepatocytes promoted by excess _
carbohydrates
G3P -> _ (1 FA, 1 OH, 1 OPO4), -> _ (2 FA, 1 OPO4) -> DAG -> TAG
G3P -> Lysophosphatidic acid -> phosphatidic acid
extra glucose in the blood form _ which is the backbone for TAG. In adipocytes there is not direct _ because…
Form G3P; in adipocytes there is no direct phosphorylation of glyercol to G3P bc glycerol kinase is absent in adipocytes
capillary lipoprotein lipase works to do what?
chips off FAs from chylomicrons and VLDLs and transport into cell
How do we accomplish TAG synthesis in adipocytes
liver makes TAGs and packages into VLDLs and release into blood; this is how we have TAG synthesis in adipocytes
FFA in TAG synthesis in adipocytes come from:
from breakdown of chylomicrons and VLDL in blood by the action of capillary lipoprotein lipase
G3P and FFA form
TAGs
TAG synthesis in adipocytes promoted by:
excess carbohydrate and fats
what is the biggest difference between TAG synthesis in liver vs adipocytes?
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.
TAGs are released from the liver in the form of _ but in adipocytes the TAGs are _ in the cells
form of VLDLs and in adipocytes the TAGs are retained in the cells
