Lipid catabolism Flashcards
Main energy storage form in adipose tissue
Triglycerides
Fatty acid structure
Mainly straight chains
Usually even number of C atoms
Double bonds usually in which configuration?
cis configuration
16:0
Palmitic acid
18:0
Stearic acid
18:1
Oleic acid
alpha carbon
C adjacent to carboxyl group
w carbon
Carbon furthest away (from the carboxyl group)
Main products of fat digestion?
Glycerol
Fatty acids
Monoglycerides
What happens to short and medium length fatty acids?
Enter portal blood
What happens to longer chain fatty acids and monoglycerides?
Resynthesised to triglycerides
Where does fatty acid oxidation occur?
Cytoplasm
- converted into CoA derivatives
- further oxidation then occurs in mitochondrial matrix
How are fatty acids transported from cytoplasm into mitochondrial matrix?
The carnitine shuttle
Where does beta oxidation take place?
Mitochondrial matrix
Products of each fatty acid cycle
1 acetyl-CoA
1 FADH2
1 NADH + H+
1 fatty acyl-CoA, shortened by 2 carbon atoms
Why do unsaturated fatty acids yield less FADH2?
They are already partially oxidised
What is cool about odd-chain fatty acids?
yields propionyl-CoA in last step (3 carbon atoms)
converted to succinyl-CoA
enters TCA cycle directly
Where would you find glycerol kinase?
ONLY IN LIVER AND KIDNEY
-activates glycerol and turns it into glycerol-3-phopshate
(it is then dehydrogenated to dihydroxyacetone phosphate)
Where are ketone bodies formed?
In the liver!!!
-important source of energy for heart muscle and renal cortex
