1. Engage Activity
Describe the concept of a lock and key.

2. Chemical Reactions and Enzymes
OBJ: Describe the structure and function of enzymes in reactions

3. Chemical Reactions Review
Process that changes, or transforms one set of chemicals into another
Reactants -> Products
Reactions always involve changes in the chemical bonds that join the atoms into compounds

4. Chemical Reactions Review
Process that changes, or transforms one set of chemicals into another

5. Energy in Reactions
Energy is released when chemical bonds are broken and absorbed whenever chemical bonds formed.
Activation energy: the energy that is needed to get a reaction started.

6. Energy in Reactions
Energy is released when chemical bonds are broken and absorbed whenever chemical bonds formed.
Activation energy: the energy that is needed to get a reaction started.

7. Enzymes
Catalyst is a substance that speeds up the rate of chemical reactions by lowering activation energy
Enzymes = biological catalysts that speed up reactions that take place in the cells

8. Enzymes
What does the graph show would be the effect if enzymes were not available within a cell?
Without enzymes, reactions would need more activation energy to get started

9. Enzymes
What does the graph show would be the effect if enzymes were not available within a cell?
Without enzymes, reactions would need more activation energy to get started

10. Enzymes
Would a reaction take a longer or shorter time with an enzyme?

11. Enzymes Would a reaction take a longer or shorter time with an enzyme?
A shorter time

12. Enzymes cont’d
Enzymes are VERY specific

13. Enzyme-Substrate Complex
Notice: Enzyme is NOT changed

14. Enzyme-Substrate Complex

15. Regulation of Enzyme Activity
Can be affected by variables that influence a reaction (i.e. temperature, pH
When an enzyme is denatured it is turned off

16. Enzymes and Digestion

17. Review: Engage Activity
Which of these is like the enzyme and which is the substrate?
Where is the active spot?
How does inserting a key into a lock different from the formation of an enzyme-substrate complex?

18. Review: Engage Activity
Which of these is like the enzyme and which is the substrate?
Where is the active site?
How does inserting a key into a lock different from the formation of an enzyme-substrate complex?

19. Review: Engage Activity
Which of these is like the enzyme and which is the substrate?
Where is the active spot?
How does inserting a key into a lock different from the formation of an enzyme-substrate complex?