1. Amino Acids
An amino acid is any compound that contains an amino group (—NH2) and a carboxyl group (—COOH) in the same molecule.

2. Peptides
A peptide is any combination of amino acids in which the amino group of one amino acid is united with the carboxyl group of another amino acid.

3. A peptide with more than about 100 amino acids is called a protein.
Proteins
A peptide with more than about 100 amino acids is called a protein.
Your skin, hair, nails, and muscles are made of protein.
Proteins are needed for almost all chemical reactions that take place in the body.

4. Enzymes are proteins that act as biological catalysts.
Enzymes increase the reaction rates of chemical reactions in living things.

5. Enzymes catalyze most of the chemical changes that occur in the cell.
How Enzymes Work
Enzymes catalyze most of the chemical changes that occur in the cell.
Substrates are the molecules on which an enzyme acts.
The place on an enzyme where a substrate binds is called the active site.

6. Enzymes
In a typical enzymatic reaction, the substrate interacts with side chains of the amino acids on the enzyme. These interactions cause the making and breaking of bonds.
A substrate fits into a distinctively shaped active site on an enzyme. Bond- breaking occurs at the active site to produce the products of the reaction. Predicting What would happen if access to the active site were blocked by another molecule?

7. END OF SHOW