Biology Exam Grade 12

functional groups

reactive cluster of atoms that attach to C backbone, posess chem prop give to mol

hydroxyl

-OH, -ol, polar → forms HB w water mol to help dissolve organic compounds (sugars)

carbonyl - aldehyde

C=O, al, carbonyl functional group at end of C skeleton

carbonyl - ketone

C=O, one, carbonyl group within C skeleton

carboxyl

OH-C=O, oic acid, acts as acid → donates H+

amino

NH2, amine, acts as base → takes H+

sulfhydryl

S-H, proteins, helps determine shapes of proteins, slightly polar

phosphate

PO34-, nucleic acids, polar + neg charged, makes mol acidic

macromolecules

large molecules sometimes composed of a great # of subunits

4 macromolecules

carbohydrates, lipids, proteins, nucleic acids

condensation

how macromolecules r made; creates covalent bond btwn 2 subunits; removes H and OH from 2 subunits functional groups; anabolic

hydrolysis

how macromolecules are broken down, water mol gives H to one subunit and OH to the other

carbohydrates

among most common organic mol, produced by plants + algae w photosynthesis, contains C, H, O in 1:2:1 ratio, energy + structural support

types of carbohydrates

monosaccharides (1 subunit), disaccharides, (2 subunits) oligosaccharides (few subunits), polysaccharides (hundreds-thousands of subunits)

monosaccharides

contains single chain of C atoms w carbonyl + hydroxyl attached, distinguished by carbonyl group + number of C in backbone

isomers

molecule w identical molecular formula but diff structural formula

isomer ex

glucose, galactose, fructose

disaccharide examples

glucose + fructose = sucrose, galactose + glucose = lactose, glucose + glucose = maltose

polysaccharides

long chains of monosaccharide subunits held tgthr w glycosidic linkages, “complex carbs)

starch

form plants store E in, straight chain alpha-glucose polymer, contains alpha 1-4 glycosidic linkages

glycogen

form animals store energy in cells of muscles + livers, highly branching, alpha 1-4 and alpha 1-6 glucose polymers, break down more easily

cellulose

tight arrangement, hard to break apart, beta 1-4 glycosidic linkages, each monomer flipped upside down compared to adjacent monomer

lipids

composed of C, H, O; insoluble in water, soluble in non- polar subs

lipid functions

energy storage, insulation, major comp of cell membrane

triglycerides

most common lipid in animals and plants, composed one glycerol three fatty acids

triglyceride formation

esterification - condensation btwn hydroxyl in glycerol and carboyxl on fatty acid

saturated fatty acids

no double bonds, HC chain close tgthr, solid consistency room temp, animal fats, moderation

unsaturated fatty acid

one (monounsaturated- olive oil) or more (polyunsaturated- veg oil) double bonds btwn C, bending, liquid room temp

hydrogenated fat pros

desirable texture, cheap, consistency range, shelf life

phospholipids

component of cell membrane, glycerol + 2 fatty acid + phosphate; phosphate group polar

phospholipid bilayer

non polar hydrophobic tails tucked away from water, polar hydrophilic heads directed toward water

hydrogenated fat cons

hydrogenation produced trans fats, body can’t process properly, raise bad LDL - cholesterol and lower good cholesterol, negative affects on cardiovascular

protein functions

catalyze, structure, transport, movement, regulating cell processes, defense

protein composition

amino acid monomers; carbonyl, H group, R group, amino group; function depends on 3D structure

peptide bond

covalent bonds holding tgthr amino acids, formed between carboxyl and amino condensation rxn, creates polypeptide chain

primary structure protein

sequence of amino acids in polypeptide chain, beads on necklace

secondary structure protein

polar peptide bonds create HB between carbonyl O and amino H; forms coil like shape (a helix) or folded dan like shape (B pleated sheets)

Tertiary structure protein

due to interactions w R groups, 3D folding on hydrophobic/philic interactions, HB, disulfide bridges, charge interactions

Quaternary Structure protein

proteins composed of more than one polypeptide

denaturation

protein unfolds, loss of 3D shape means loss of function, change in temp, pH, salt [], not in natural env, can only be reversed if peptide bonds intact (slight heating)

DNA

thymine, long double stranded, genetic coding

RNA

protein synthesis, single stranded