1. Macromolecules Protein

2. Proteins Probably the most diverse group of macromolecules is the proteins.

3. Proteins Proteins are complex polymers composed of C, H, O and N. Polymer : large molecule formed when many smaller molecules bond together

4. Proteins The building blocks of proteins are smaller molecules called amino acids held together by peptide bonds Most end in “-ine” Despite the wide variety of life on Earth, all living organisms use only 20 different amino acids to produce the proteins they require

5. Proteins Green plants can make all 20 essential amino acids on their own; animals cannot. Thus, animals, including humans, must get some of these essential amino acids from the foods they eat.

6. Proteins Enzymes are important proteins found in living things. An enzyme changes the rate of a chemical reaction. Enzymes are involved in nearly all metabolic reactions Usually end in “-ase”

7. Proteins Substrate- Component in an enzyme reaction Enzyme reactions take place in the active site Substrate + Enzyme Product + Enzyme The enzyme is unchanged in the reaction.

8. Proteins Each enzyme is specific to only one reaction. This reaction is often compared to a lock and key.