Fats Flashcards
Essential Fatty Acids
- eicosanoids
Linoleic omega6
alpha Linolenic omega3
“beta oxidize fats” to …
C2 units, AcetylCoA
“esterify” FA’s to…
TG’s
- stabilizes
“phosphatidyl”
fat anchor to nutrient so that it may travel to cell membrane
- TG group
- also see “acyl glycerol”
What does insulin cause the LR to do with acyl units (fat)?
esterifies them to TG’s and releases to blood stream
- if no insulin (so no sugar avail), then LR will beta oxidize in mitochondria for Energy
What is cardiolipin?
phospholipid
- “diphoshatidylglycerol”
- inner membrane of mitochondria
- phosphate transporter, cytochrome oxidase activity
major site of cholesterol synthesis
- where
LR
- cytoplasm
Free fatty acids -> Cholesterol pathway
FFA -> Acyl CoA -> Acetoacetyl CoA -> HMG-CoA -> Mevalonate -> Squalene -> Desmusterol -> Cholesterol
Cholesterol synthesis:
rate limiting step
HMG CoA Reductase
HMGCoA —> Mevalonate
inhibited by cholesterol
Cholesterol synthesis:
Mevalonate –> –>
IPP + DPP
- 5C isoprenoid isomers
Cholesterol synthesis:
IPP & DPP –> –>
Squalene -> Ianosterol -> Cholesterol
chylomicron receptor
Apo-E
LDL receptor
Apo-B
HDL receptor
A-1
VLDL -> IDL -> ?
LDL
HDL and LDL are synthesized by…
LR
- vs chylomicron - we get from diet
Why is HDL so good?
takes oxidized TG’s from LDL, VLDL, chylomicrons and gives esterified cholesterol
LDL delivers cholesterol to peripheral tissues
for hormone synthesis and cell membrane
HDL at peripheral tissue
picks up extra cholesterol from cells
ACAT does what
takes free cholesterol and esterifies it to stabilize it in the peripheral tissue cells
CE Hydrolase does what
in peripheral tissue cells makes esterified cholesterol free to use for steroid synthesis
fat soluble antioxidant
tocopherols like vit E
- carried on LDLs
plasma antioxidant
ascorbate
rbc antioxidant
glutathione
eicosanoids –>
prostanoids
prostanoids include
Prostaglandins
Thromboxanes
Leukotrienes
Eicosanoids:
anti-inflammatory
series 1 and 3
linoleic, linolenic
Eicosanoids:
pro-inflammatory
arachadonic acid aka series 2
Where do you get linoleic acid (omega6)
vegetables, seeds, nuts
Where do you get alpha linolenic acid (omega3)
flaxseed
Where do you get Arachadonic Acid?
animal fats
Where do you get EPA/DHA?
fish… or from alpha-lenolenic acid
Eicosanoids:
if increase in Delta-5 Desaturase…
increase proinflam cytokines
series 2 and 1
- stimulated by insulin
Eicosanoids:
Series 1 & 3 use what enzyme to make anti-inflam enzymes?
Delta-6 Desaturase
Eicosanoids are made by
oxidation of 20C FA’s
Which enzymes gets Arachadonic Acid out of the phospholipid membrane of a cell?
Phospholipase A2
Phospholipase A2 is stimulated and inhibited by?
Stimulated: Angiotensin ll, bradykinin, EPI, Thrombin
Inhibited: corticosteroids
NSAIDS block what enzyme? from making what?
Cyclooxygenase
- Arachodante –> PGs, Thromboxanes
Arachadonate –> Leukotrienes
enzyme?
Lipoxygenase
Which enzyme is affected by statin drugs?
HMG-CoA Reductase - inhibited preventing synthesis of mevalonate and thus cholesterol
Desmusterol –> Cholesterol
enzyme
Delta-24 Reductase
Esterification of what leads to TG’s
Acyl CoA
HMG-CoA –> Mevalonate
enzyme
HMG-CoA Reductase
HMG-CoA –> Acetoacetate ( -> ketone)
enzyme
HMG-CoA Lyase
Enzyme responsible for breakdown of TG’s in adipose cell to FFA’s
Stimulate?
Inhibit?
Hormone Sensitive Lipase
- stimulated by EPI and Cortisol
- inhibited by insulin
Ketones are toxic to ? but can be used by what and what for E.
toxic to LR
- muscle and brain can use for E
How to get Fat into Mitochondria for E?
use?
CPT l
CPT ll
CAT
Where is CPT l and what does it do?
Outer mitochondrial membrane
- takes CoA off fat and puts carnitine on
Where is CAT and what does it do?
Inner mitochondrial membrane
- delivers fat to CPT ll and recycles Carnitine
Where is CPT ll and what does it do?
Inner mitochondrial membrane
- forces fat into mitochondria
Where does metabolism of the FFA take place?
LR
