Chemical Reactions

1. Chemical Reactions How Enzymes Function

2. Chemical Reaction • A chemical reaction is a process that changes or transforms one set of chemicals into another. • Reactants: the elements that you start with in your chemical reaction • Products: the elements that you end with • Examples: rust of metal, the formation of water

3. How Enzymes Function • Enzymes speed up cellular reactions by lowering the amount of energy needed to start the reaction. • The energy level that must be overcome before a chemical reaction can begin is called the activation energy.

4. How enzymes function • Enzymes act as molecules that function as catalyst. • Catalysts speed up chemical reactions • Enzymes increase the rate of reactions without being changed or used!

5. Importance of Enzymes • Without enzymes the chemical reactions in the body would not take place fast enough to sustain life.

6. Enzymes

7. Specificity • Specific enzymes work for specific reactions. • The shape of the enzyme determines the chemicals it catalyzes. • A specific reactant that an enzyme acts on is called a substrate.

8. Substrates • A substrate fits inot a region of the enzyme called the active site. • When a substrate binds to the active site it slight changes shape. • The way substrates fit into enzymes is called the lock and key model.

9. Cellular Effects on Enzymes • The environment of a cell may have an effect on enzyme activity. • Temperature • Salt concentration • pH • The enzymes work best when organisms fall in homeostatic ranges.