Bioenergetics - lipids

what are lipids made up of

carbon, hydrogen and oxygen

proportion of oxygen much smaller than carbs and protein

properties of lipids

not polymers

non polar, hydrophobic

soluble in organic solvents

function of lipids

source of energy

form body structures

regulate metabolism

enhance absorption of fat soluble vitamins

provide insulation

what are fatty acids 

building blocks for triglycerides and phospholipids

chain of carbon and hydrogen atoms with a carboxyl group at the alpha end and a methyl group at omega end 

short chain fatty acids

2 to 4 carbons

liquid at room temp

medium chain fatty acids

6 to 10 carbons long

long chain fatty acids

12 or more carbons

what are saturated fatty acids

all carbons bound to hydrogen

usually more solid at room temp

higher melting point

what are unsaturated fatty acids

some carbons form a double bond with each other instead of binding to hydrogen

monounsaturated fatty acid

one carbon to carbon double bond

polyunsaturated fatty acid 

2 or more carbon to carbon double bonds 

properties of unsaturated fatty acids

liquid at room temp

lower melting point

omega 3

first double bond between 3rd and 4th carbon from the omega end

omega 6 

first double bond between the 6th and 7th carbon from the omega end 

what 2 shapes can unsaturated fatty acids have

Cis form and Trans form

what is Cis form unsaturated fatty acids

hydrogens are on the same side of the double bond

what is trans unsaturated fatty acids

hydrogens are on opposite sides of the double bond

what is hydrogenation

a chemical process that adds hydrogen to the unsaturated bonds on the fatty acid chains attached to the triglyceride backbone

structure of a phospholipid

glycerol

2 fatty acids

phosphate group

functions of phospholipid 

main lipid consistuent of cell membranes 

lipid transport as part of lipoproteins

emulsifiers

cell signalling process

what is the lipid bilayer of cell membranes 

prevents proteins and molecules diffusing into unwanted areas 

impermeable to most water soluble molecules

adopts a solid gel at low temp and fluid at high temp

what is a sterol

compound containing 4 connecting rings of carbon and hydrogen

don’t provide energy

structure of a sterol

4 rings

hydrocarbon side chain

alcohol group

what are sterols used in 

bile acids

sex and adrenal hormones

vitamin d 

what is cholesterol

type of sterol

structure of a triglyceride

glycerol

3 fatty acids

functions of triglycerides 

energy source

insulation and protection

carrier of fat soluble vitamins

what are the polymers of amino acids

polypeptides

what charge do acidic amino acids have

negative

what charge do basic amino acids have 

positive