Proteins B 1.2

Alpha carbon

Alpha carbon

The central carbon atom within an amino acid

Structure of an amino acid

Contains an amine group and a carboxyl group

Amphiprotic

Amino acids are _____ because the amine group is basic and the carboxyl group is acidic

Peptide bonds

Bonds formed by the creation of a dipeptide

Dipeptide

When two amino acids are linked through a condensation reaction (catalyzed by ribosomes)

Essential amino acids

Can’t be synthesized using metabolic pathways, therefore must be eaten to receive

Non-essential amino acids

Can be synthesized by metabolic pathways

Animal based foods

Have a balance of amino acids

Plants

Deficit in specific amino acids

Beta-endorphins

A protein that acts as a natural pain killer (secreted by the pituitary gland) (31 amino acids)

Alpha amylas

An enzyme in saliva that begins the digestion of starch (496 amino acids)

Titin

Protein that is part of the muscle (has 34,350 amino acids — more in mice)

Denaturation

The disruption or breaking of bonds between the R group of amino acids

Heat as a cause of denaturation

Causes vibration within the molecule →weakens/breaks imfs/interactions

PH as a cause of denaturation

At extremes causes denaturation because positive and negative R-groups are changed → breaking ionic bonds within the protein or causing new ones to change shape

Polypeptide backbone

Repeating sequence of atoms linked by covalent bonds

a-helix

Polypeptides wind into a helical shape with bonds between adjacent turns of the helix

B-pleated sheet

2+ sections of a polypeptide are arranged parallel with H bonds between them

Collagen

Rope like structure with high tensile strength (used in skin, tendons, and ligaments)