Proteins

Functions of Proteins

Movement, structure and support, hormones and enzymes, protection, regulation

What sided amino acids are more prominent/naturally occuring?

L-Amino Acids (amino group on left side)

What is the only one that forms a ring to the backbone, and what does it do?

Proline - makes polypeptide less flexible

Isoelectric Point

electrically neutral. zwitterion at body pH.

peptide bond

amide linkage

Naming Peptides

naming initiates at the N-terminus and proceeds to right (to C-terminus)

Keratins (a-keratin)

Found in skin, wool, hair, hooves, and fingernails

Silk in beta keratins

Collagens

found in animal hide, tendons, bone, eye cornea, and other connective tissue

Scurvy

Vitamin C required for hydroxyproline which makes the triple helix of collagen. deficiency - tissues and blood vessels break down

Every third residue of collagen is

glycine - 3.5 residue

Denaturation

A process in which a protein unravels, losing its specific structure using heat

(and detergent/soap, mechanical - whipping eggs, organic solvents)

BSE Disease vs. Creutzfeldt-Jakob Syn

Cascade of denaturation for consumers vs. random mutation for genetic inheritance

Sickle Cell Anemia

Missing two glutamates (creates -2), CRISPR-Cas9 = gene editor

Rhodopsin

Retinal that can flip from cis to trans in presence of light, embedded in membrane.

Coiled Coils

a-keratin with a 3.5 residue turn. 1st and 4th are greasy and hydrophobic (heptad repeat)

two a-helices.

Triple Helix

Collagen, need vitamin c to make. L handed helixes and R handed formation.

Denaturation - unravels

Heat, detergents, mechanically, stomach acid.

Prions

Denature into B-sheets.

Cofactors - tools enzymes need to function.

Metal ions (catalytic or structural), coenzymes (NAD+ catcher).

Isoenzymes

Enzymes in bloodstream that shouldn’t be there that are specific to a tissue.

Allosteric control

(-) if binds = gone. (+) if binds = appears.

Reversible inhibition

Covalent (“grenade”), competitive, and noncompetitive.

Competitive vs. noncompetitive vs. irreversible

bind to active site and block vs. bind to allosteric (change the response) vs. binds and won’t let go (poison)

Vitamins

Build the cofactors enzymes need to work.

RFLP analysis

Gene matching for families

PCR

2^n sets of dna. n sets of over-runs.

primary vs. secondary vs. tertiary vs. quaternary

polypeptide chain — hydrophobic forces drive H-bond (a-helices, B-sheets, loops, tiple helix) — overall fold — globular proteins (2+ tertiary)

cooperativity

sigmoidal curve like in hemoglobin when one O binds, the rest flip and bind to O too.

Hydrolysis of proteins

need >6M of boiling acid or base to fully separate.