Proteins are polymers of amino acids

Usually saturated carbon chains that contain an amino group (NH₃) and a carboxylic acid group (COOH)

Shape

Solubility

Composition

Albumins - body fluids and plant seeds; rich in asprartic and glutamic acids (20-25%) and leucine and lysine (16%)

Globulins - all animal and plant cells

Glutelins- all grain seeds and contain glutamic (45%)

Prolamines- cereals: wheat, corn, barley (proline 15%)

Histones- cell nucleus, high in ess. A.A.

Protamines- DNA - contain 80-85% arginine

Usually associated with enzymes

Collagen- connective tissue and make up of 25-30% of total body protein

Elastins- Elastic fibers of tendons, ligaments, bronchi and arterial cell walls. High Valine, Isoleucine, and Leucine (30%)

Keratins- skin, fur, feathers, wool, claws, hooves, beaks. High cystine

Reason for Feather Meal fed to cows

Carbon- 51-55%

Hydrogen- 6.5-7%

Nitrogen- 15.5-18%

Oxygen- 21.5-23.5%

Sulfur- 0.5-2%

Phosphorus- 0-1.5%

Amino Acids can be:

Neutral

Acidic

Basic

If neutral, can have both a neg and pos group- but is overal a neutral value

If Acidic- can have pos and neg groups, but overall negative

If Basic- can have pos and neg groups, but overall positive.

high concentration when pH is low

both amino and carboxyl group are protonated

Many H around to protonate

High concentration at high pH

Both amino and carboxyl groups are deprotonated

Less H in solution

Single bond that occurs when two amino acids go through a dehydration process to create one dipeptide.

The carboxyl end of one a.a. loses an O and the amino group of the other a.a loses 2 molecules of H to form the bond.