OPT 116: Biochemistry Lipids I

lipids

serve as a reserve supply of energy; organic compounds that are largely hydrophobic; mainly carbon and hydrogen, some oxygen

TAG/triacylglycerides

during periods of low food consumption, _____ can be broken down to produce energy

fatty acids

precursor of triglycerides; source of energy

triglycerides

energy storage; thermal insulation; filling space; binding organs together; cushioning organs

phospholipids

structural components of cell/organelle membranes; aid in fat digestion

sphingolipids

structural component of cell membranes (especially nerve cells); chemical messengers

cholesterol

component of cell membranes; precursor of other steroids

steroid hormones and eicosanoids

chemical messengers

bile salts

aid in digestion and nutrient absorption

fat-soluble vitamins

Vitamins A, D, E, K; involved in a variety of functions including blood clotting, wound healing, vision, calcium absorption

simple lipids

esters of fatty acid

triglycerides, triacylglycerol (TAG)

examples of simple lipids

complex lipids

esters of fatty acids + additional groups

phospholipids and sphingolipids

examples of complex lipids

derived lipids

lipids derived from the hydrolysis of simple/complex lipids

steroids, isoprenoids, eicosanoids

examples of derived lipids

bile salts, steroid hormones, sterols

examples of steroids

vitamins A, E, K

examples of isoprenoids

prostaglandins, thromboxanes, leukotrienes

examples of eicosanoids

fatty acid

a hydrocarbon chain with a carboxyl group at one end; typically has even number of carbons

even

A fatty acid usually has an ______ number of carbons

Palmitic acid (hexadecanoic acid)

_____________ is the most common saturated fat in plants and animals

omega number

_________ _________ refers to the position of the 1st double bond relative to the methyl end (omega end)

single bonds

saturated, linear, solid

double bonds

unsaturated, bent, liquid

cis or trans

unsaturated fatty acids have either ______ or ______ configuration

cis

2 hydrogens attached to the carbon double bond are on the same side; most commonly occurring unsaturated fatty acids

trans

2 hydrogens attached to the carbon double bond are on the opposite side; hydrocarbon chain is straight

unsaturated trans; unsaturated cis

What's "1" and "2"?

trans fatty acids

Most ______ ______ ______ are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid

ester of a fatty acid

alcohol + fatty acid

alcohol

compound that contains hydroxyl groups attached to carbon

glycerol and sphingosine

examples of alcohols

triglycerides (AKA triacylglycerol, TAG, fats, oils)

3 fatty acids + glycerol; hydrocarbon chain length varies; degree of unsaturation varies; storage form of fatty acids

phospholipids

2 fatty acids + glycerol + phosphate + 1 polar group

phosphate; polar head group; glycerol backbone; fatty acids chains

This is a phospholipid. What's "1","2","3", and "4"?

possible polar groups of phospholipids

ethanolamine, serine, inositol, choline

ethanolamine

found in cell membranes and pharmaceuticals

serine

metabolism and immune system

inositol

signal transduction

choline

cell membrane maintenance

sphingolipids

fatty acid + sphingosine + 1 head group

possible head groups of sphingolipids

hydrogen (ceramides), phosphocholine (sphingomyelin), and sugar (glycolipid)

sphingosine; fatty acid; head group (sugar in this case)

This is a sphingolipids. What's "1","2", and "3"?

1 sugar

cerebroside

>1 sugar

ganglioside

rhodopsin

the pigment in rod cells that causes light sensitivity