Fatty Acids
Sources of fatty acids
diet
anabolic processes from glucose (in liver and adipose tissue)
Structure?
4 ringed structure called a steroid nucleus
fatty acids
triaglycerides
phospholipids
steroids
what is it made of
1 glycerol and 3 fatty acids
main components and if they're polar
- diacylglycerol (triglyceride but 2 alkyl chains instead of 3)
- phosphate
- R group (always polar)
Key intermediate for fatty acids
Citrate
Common examples of steroids
- cholesterol (cell membrane fluidity)
- glucocorticoids (ex: dexamethasone turns off immune system)
- estrogen
- testosterone
- bile acids (derived from cholesterol, secreted from liver -> dissolves into fat)
What are fatty acids, which parts are fats vs acids
hydrocarbon chains with carboxyl group
- fat: alkyl chain
- acid: carboxyl group
how is it used and where is it stored
lipid storage, stores energy for when none other is available
adipocytes
How are they amphathic
What is it used for
membrane bilayers
precursor for synthesis: bile acids, steroid hormones, and vitamin D
Differences between saturated and unsaturated
- no double bonds
- usually solid at room temp
Unsaturated:
- double bonds (make it kinked)
- not saturated with hydrogens, less H bonds
how is it linked together and on what part of glycerol is it attached to
covalently linked on the OH (carboxyl group) of the glycerol
dehydration reaction forms ester bond
Common lipids
- phosphatidylserine (cell membranes)
How to get triglycerides
- diet by not absorbed intact
- synthesized from glycerol and fatty acids in liver
- can also be derived from glucose
What is cholesterol associated with disease wise
cardiovascular disease
What does it mean for a fatty acid to be 18:0
18 carbons, 0 double bonds
Where is lipid synthesis
- smooth ER
- electron carrier to NADPH