Presentation on theme: "ENZYMES. Enzymes are biological catalysts, which work to speed up a chemical reaction. Without enzymes, several reactions in cells would never occur or."— Presentation transcript:
Enzymes are biological catalysts, which work to speed up a chemical reaction. Without enzymes, several reactions in cells would never occur or happen to slowly to be useful. ENZYMES – A SPECIAL TYPE OF PROTEIN
Activation energy is the energy needed to get a chemical reaction started ENZYMES LOWER ACTIVATION ENERGY.
When activation energy is lowered, the reaction speeds up. EFFECT OF ENZYMES
Enzymes provide a site where reactants can be brought together to react. This is site is called the active site. The reactants are called the substrates. The shape of an enzyme is so specific that generally only one enzyme will work for one substrate. Therefore, enzymes are said to fit together like a lock and key. ENZYME ACTION
Since only the substrate changes during the reaction, the enzyme can be reused again and again. ENZYME ACTION
Enzymes work best at specific temperatures and pH. Heating can change the enzyme shape and the wrong pH affects the binding of the substrate to the enzyme. Ergo, enzymes in our body work best at 37°C (98.6°F) and at a pH between 6.5 to 7.5. Also, most cells contain proteins that turn enzymes on or off during critical stages of development. ENZYMES CAN BE TURNED ON AND OFF.