PROTEINS

Proteins Composed mainly of –Carbon –Hydrogen –Nitrogen

PROTEINS HAVE MANY FUNCTIONS! EX: CONSTRUCTION MATERIALS FOR THE BODY, FOUND IN –MUSCLES –SKIN –BLOOD.

Made up of smaller units called AMINO ACIDS Our bodies contain thousands of different proteins. All are made from about 20 different amino acids. Amino Acids of Protein

Amino acids differ ONLY in the type of R Group they have. – causes different shapes and different functions

Amino Acids bond to form a DIPEPTIDE, during D. S. Form a covalent bond, called a PEPTIDE BOND.

Amino Acids of Protein Many amino acids can bond, forming a long chain called a POLYPEPTIDE.

A protein is a polypeptide

Amino Acids of Protein Proteins are composed of one or more polypeptides. Some proteins are very large molecules, containing hundreds of Amino Acids.

Shape Determines Function Proteins are often bent and folded because of bonding among amino acids Denaturing Proteins –Caused by change in temperature, pH Cooking an egg Certain hair styles

4 Levels of Protein Structure Primary – sequence of amino acids Secondary – H bonds between A.A. cause coil or pleats. Tertiary – Protein folds more Quaternary – made up of different subunits all put together

Enzymes are types of Proteins ENZYMES – speed up chemical reactions (act as a catalyst!) by lowering the amount of energy it takes for the reaction to occur. (ACTIVATION ENERGY)

Enzymes are shape-specific. Substrate molecule must fit the active site.

After the reaction, the product is released, enzyme is unchanged, so it can be used many times. Enzymes

REVIEW a. Substrate binds to Enzyme b. Chemical Reaction c. Products Formed; Enzyme Unchanged