Daily Starter Tuesday, Day 11 compare the side groups of polar amino acids vs. non polar amino acids

“Protein” Gets its name from the Greek word meaning “first” or “primary” material of primary importance in every process that has to do with being alive Without proteins, No chemical reaction in a living thing would happen at a useful speed

Enzymes These are the proteins that allow chemical reaction to take place at a useful speed All enzymes are proteins More on enzymes later…

The Transport protein Proteins act as transporters to carry things: in the blood across membranes (barriers) Transport electrons that are removed or added in chemical reactions

Other protein functions… In claws, hooves, hair, nails Muscle contraction and movement within cells

Zwitterions Under the conditions found in most living cells (pH ~7), nearly molecule of any amino acid is doubly ionized The carboxyl group releases a hydrogen (donate = acid) and becomes (-) charged The amino group picks up a hydrogen (accept = base) to become (+) charged

Dehydration Condensation Just like carbohydrates and fats, proteins are assembled by a dehydration condensation of their subunits This happens when the covalent bond joins 2 amino acids, called a peptide bond

Peptide Bonds When a covalent bond joins amino acids, a peptide bond is formed The resulting molecule is called a dipeptide (2 amino acids)

Peptide Bonds Peptide bonds Adding 1 more amino acid forms a tripeptide (3 amino acids)

Peptide Bonds More than 3 amino acids is a POLYPEPTIDE