Biochem: lipids and membranes

Question 1

Most important functions

Answer 1

1. Components of membranes*
2. Storage form of carbon and energy* ( HEAVILY REDUCED- has lots of H to form NADH, ADH FOR ATP)
3. INSULATION (FAT FOR PROTECTION)
4. PROTECTIVE COATINGS SO NO EXCESSIVE LOSS OF H20 (WAXES) BIRD EX

Question 2

Fatty acids (FAs)

Answer 2

FAs are amphipathic long chain

aliphatic carboxylic acids.

longer chain= more water to form cages= unfavoured= least soluble

released from fat by hydrolysis
ex: suck on fat will cut these

not often in free form (always in bilayer, micelle, etc)

Question 3

Fatty acids can be:

Answer 3

monocarboxylic acids: linear, even # of C atoms, C12 to C24.

unsat: 1 or more double bonds, but separated by ch2

always in cis if unsat
trans= in food industries unatural in body since we dont have enzymes to break trans

Question 4

saturated vs monosaturated

Answer 4

1. linear, very close together meaning more rigid and more vdw. need more heat to break
2. at double bond it causes bend (more wiggle room between them), less heat to break and turns oily more quick

Question 5

pka of fatty acids
melting point properties
solubility
form

Answer 5

4.5-5

chain L up= mp up

double bonds up= mp down

amphiatic and is soluble in water up to c6 then only in non-soluble polar solvents

micelles