1.2 chemistry of life 2

lipid

biomacromolecule not soluble in water, made up of primarily of hydrocarbon chains with some oxygen and sometimes phosphorous or nitrogen

fatty acids

long non-polar hydrogen chains with a COOH on end

triglyceride

most abundant lipid in living things, act as reserve fuel storage, three carbon glycerol attached to three fatty acids

adipocytes

fat cells, where triglycerides are stored

chylomicron

triglyceride plus cholesterol, formed after absorbing broken down fatty acids in intestines

phospholipid

polar head group joined to non-polar tail group

amphipathic

“of both kinds” describes phospholipids which are polar

phospholipid head group

negatively charged phosphate group and positive, usually nitrogen containing group, hydrophilic

tail group of phospholipid

hydrocarbon chain, hydrophobic

steroid

lipid made up of four fused carbon rings with other functional groups, most commonly alcohols, unique structure from other lipids

cholesterol

a steroid that is essential structurally in animal cell membranes, but forms arterial plaque in excess, which can cause heart attacks. bile salts, estrogen, progesterone, testosterone synthesized from cholesterol

protein functions

(1) can act as enzymes and regulate metabolic functions

(2) store amino acids

(3) act as hormones

(4) form antibodies for immunological defense

(5) act as carriers for transport and also form membrane channels

(6) form cell surface receptors to receive chemical messages

(7) act as structural molecules for support and movement

amino acids

organic compounds that serve as the foundational building blocks of protein, 20 of them make up all naturally occurring proteins

enzymes

protein catalysts that speed up reactions

hemoglobin

protein that carries oxygen in red blood cells

essential amino acids

humans must get from food

non-essential amino acids

amino acids that the body can manufacture

phenylketonuria

no phenylalanine hydroxylase makes it so the body cannot break down phenylalanine

peptide bond

holds amino acids together to form proteins

polypeptide

a long chain of amino acids

primary structure

order of amino acids in a protein

collagen

an important protein in skin, tendons and ligaments, provides elasticity and strength because of its   triple helix secondary structure

α-helix

a spring-like coil configuration that comprises the basic structural unit  of some fibrous proteins that make up wool, hair, skin, and fingernails. These fibers are elastic and can stretch to some extent

ß-sheet

formed when a polypeptide chain snakes back and forth alongside itself, making a pleated sheet that is strong and flexible, but not elastic