1. ENZYMES

2. WHAT IS AN ENZYME? organic catalyst
catlalyst - assists the reaction but remain unchanged when the reaction is over. Reusable
each chemical reaction requires one enzyme

3. modify the rate of reactions structure
large complex proteins consisting of one or more polypeptide chains whose names end in –ase
substrate – substance worked on by enzyme

4. ENZYME SUBSTRATE maltase maltose lipase lipids protease proteins
amylase amylose

5. protein nature – either all protein or proteinc with non-protein parts, called coenzymes – also known as VITAMINS
active site – formation of pockets into which reacting molecules fit

6. HOW DO ENZYMES WORK? 2 MODELS OF ENZYME FUNCTION
ENZYME-SUBSTRATE COMPLEX
“LOCK AND KEY” MODEL

7. ENZYME SUBSTRATE COMPLEX
enzyme forms a temporary association with a substance whose reaction rate is affected
close physical association between enzyme and substrate is formed  enzyme-substrate complex

8. enzyme action takes place in enzyme-substrate complex
upon completion of reaction, enzyme and product(s) separate, enzyme is available for another reaction

14. LOCK AND KEY MODEL
particular enzyme will usually only form a complex with one particular type of substrate

16. WHAT INFLUENCES ENZYMES?
TEMPERATURE
AMOUNT OF ENZYME & SUBSTRATE pH

17. TEMPERATURE reaction rate increases until an optimum temperature
enzyme action rate decreases
At high temperatures, enzymes denature

18. AMOUNT OF ENZYME & SUBSTRATE
when an excess of substrate is added, the rate of enzyme action increases to a point then remains fixed as long as the enzyme concentration remains constant

19. pH
enzymes work best at different pH ranges

20. **a pH of 7 provides the optimum environment**
acids - high H+ concentration which means LOW pH – below 7
bases – low H+ concentration which means HIGH pH – above 7