lipids 2nd exam

lipids define

1 of 4 large biomolecules in cells; NOT soluble in water (hydrophobic)

hydrocarbons

dominated by c-c and c-h bonds

hydrocarbons w/o double bonds are

saturated

what interactions do saturated hydrocarbons make & why

Hydrophobic interactions b/c the bonds can pack tightly together

when does bending occur in a hydrocarbon

>= 1 double bonds btwn carbon atoms in a chain

are double bonds in a hydrocarbon unsaturated or saturated? + why?

unsaturated due to double bonds creating a rigid bend that pushes the molecules apart, preventing the molecules from lining up close to eachother.

how do fluids vary in fluid?

can be solid (ex. wax) b/c saturated waxes do not melt due to strong bonds

can be liquid (ex. oil) b/c unsaturated bonds are weak + cannot remain in original state

what size hydrocarbons create fluids?

SHORT hydrocarbons create fluid lipids b/c of the “kinks” double bonds that have weak hydrophobic interactions.

3 types of lipids

fats, steroids, phospholipids

what are fats?

made up of 3 hydrocarbon rich molecules (fatty acids) all attached to a 3 carbon molecule (glycerol)

hydrocarbon w/ a carboxyl group on the end

why are fats important

energy processing + storage

what are steroids

bulky structure that varies in the r-groups attached to the core structures

hydroxyl group on 1 end

hydrocarbon tail w/ 8 carbons on another (cholesterol)

what are phospholipids

long hydrocarbon “tail”

a head( 1 full neg. charge) that includes a phosphate + polar group

what does each phospholipids have

1) diff polar group

2) hydrocarbon tails that vary in length and/or degree (tail has 1 unsaturated + 1 saturated hydrocarbon chain)

amphipathic lipids

has an -oh (hydroxyl) group on the end + hydrocarbon tail

dual sympathy (hydrophilic and hydrocarbon region)

example of amphipathic lipid?

cholesterol

what happens if u add phospholipids to water + shake vigorously

spherical structures called vesicles form

vesicle formation

spontaneous formation (process w/o input of energy)

hydrophobic tails interact w/ eachother

hydrophilic heads interact w/ water inside + outside the vesicle

why do vesicles naturally form in water

more stable due to

hydrophobic interactions among the hydrocarbon tails on phospholipids in a bilayer

hydrogen bonding btwn h20 & hydrophilic heads

isomers

same chemical formula but structurally different

cis v trans configuration

trans configuration = straight + opposite hydrogen bonds on side

cis = bent + same side hydrogen

compartmentailzations

allows diff. environments, allows specialized functions