molecules of life

what is a macromolecule?

proteins, nucleic acids, carbohydrayes, lipids. make up about 20% by mass of the tissue of an organism. biological polymers (except lipids maybe, not repeating has 3 fatty acid and glycerol)

functional group that links carbohydrate molecules?

glycosidic bonds/ether link

starch

branced polysaccharide of glucose, easily degraded by enzymes, primary energy storage compound in plants

glycogen

often called “animal starch”, same molecular structure as starch and easily degraded.

polymer of glucose with alpha 1,4 glycosidic bonds; alpha 1,6 glycosidic bonds produce branching at carbon 6, primary energy storage compounding animals, fungi and bacteria

cellulose

is a linear polysaccharide of glucose, more chemically stable than starch. bond is slightly different shape changing orientation of bonds: beta 1,4 instead of glyco 1,4. needs different enzyme to break it cellulase, humans cannot digest

functional group that links amino acid monomers

peptide bonds

structure of protein

primary - chain

secondary - alpha helix and beta pleated sheets

tertiary - 3D structure - polypeptides fold, forming specific shapes (hydrogen bonds, disulfide bridge)

quaternary - two or more polypeptides assemble to form larger protein molecules (hydrogen bonds, disulfide bridges, hydrophobic interactions, ionic bonds)

denature protein

protein is altered of their side chain

ways a protein can be denatured

pH, temp increase, high concentration, nonpolar substance

how does pH denature protein

forms a charge with r group, changes charge of r group, no longer does its job

how does temperature increase denature protein

will disrupt any hydrogen bonding by adding energy, cause them to be too excited and move apart

how does high concentration denature protein

disrupts protein’s ability to make dipole dipole and hydrogen bonds with its substrate

how does nonpoalr substance denature protein

will deactivate it through hydrophobic interactions being disrupted by the presence of a high concentration of a nonpolar substance

physical and chemical properties of lipids

insoluble in water

non polar, held together by weak dispersion forces

dissolve readily in organic solvents

composed mainly of C, H and O

differ form carbohydrates due to a smaller proportion of oxygen

may contain other elements (phosphorus and nitrogen)

why are lipids not water soluble

non polar do not have a neg and pos charge, not susceptible to bond to any molecule, so will not form hydrogen bonds with water, not soluble

saturated fatty acid

single bonds only, can pack closely together

unsaturated fatty acid

double or more bonds, can’t pack closely together

functional group common to triglycerides

glycerol combined with three fatty acid molecules

bonding linking monomers of lipids

ester bonds link fatty acids and glyceorl

bonding linking monomers of carbohydrates

glycosidic bonds bond monosaccharides

bonding linking monomers of nucleic acids (DNA and RNA)

phosphodiester bonds link nucleotides together

bonding linking monomer of protein

peptide links bonding amino acids

general properties of lipids

hydrophobic tail - nonpolar

hydrophilic head of phospholipids - polar so soluble in water

three domains of life

bacteria, archea (prokaryoticO, eukarya

difference between bacteria and archea

bacteria has peptidoglycan wall, archea do not

gram positive bacteria

stains purple, simple cell wall, single layer, thick cell wall

gram negative bacteria

structurally complex cell wall, double layered thin cell wall