1. Enzymes
Chapter 2 section 4

2. What you should be able to do….
Describe how enzymes regulate chemical reactions in the body.

3. What are chemical reactions?
Process that transforms, changes, one set of chemicals into another by changing the chemical bonds that join the atoms in the compounds
Reactants  Products

4. What is activation energy?
Energy needed to get a reaction started

5. Enzymes Proteins Organic catalyst Work best at a specific pH
Work in and out of cells+
Roles
Regulate chemical pathways
Make materials that cells need
Release energy
Transfer information

6. Catalyst speed up reaction by lowering the activation energy
How does a catalyst affect the activation energy of a chemical reaction?
Catalyst speed up reaction by lowering the activation energy
Catalyst are not altered or used up in any way

7. Substrates bind to an enzyme at certain place called active sites.
Describe how the interaction between an enzyme and its substrates change a chemical reaction.
Substrates bind to an enzyme at certain place called active sites.

8. Describe how the interaction between an enzyme and its substrates change a chemical reaction.
An enzyme brings substrates close together so that they can react, and slightly alter (weaken) the bonds by lowering the activation energy within the substrates and by changing the shapes of the molecules.

9. Describe how the interaction between an enzyme and its substrates change a chemical reaction.
The catalyzed reaction forms a product that is then released from the enzyme.

10. Factors that influence enzyme activity
Temperature pH
Proteins in the cell

11. Name some biological processes that require enzymatic activity.
Muscle contraction, DNA replication, cell division, digestion

12. Some organisms live in very hot or very acidic environments
Some organisms live in very hot or very acidic environments. Would their enzymes function in a person’s Cells? Why or why not?
No, because they function under different conditions than found in humans. Therefore, if they were placed in humans they would become denatured and no longer work.

13. Suppose that the amino acids that make up an enzyme’s active site are changed. How might this change affect the enzyme?
The substrates would likely not bond to the enzyme because the shape of the active site would change.

14. How do enzymes maintain specificity?
Regions of the enzymes bind only to certain substances

15. Relate the specificity of an enzyme to the analogy of a lock and key.
Enzymes interact only with substrates of certain structure because the active site (where the substrate binds) is designed to allow only molecules of specific shapes and sizes to fit, much like a key fits only into a lock of a certain size and shape.

16. Describe 2 functions of catalysts in chemical reactions.
Catalysts decrease activation energy and increase reaction rate.

17. APPLY: How does the structure of an enzyme affect its function?
If the structure of an enzyme changes, its function will also change.

18. Organisms need to maintain homeostasis
Organisms need to maintain homeostasis. Why is homeostasis important for the function of enzymes?
If homeostatic conditions, such as temperature or pH, are not maintained; then, the hydrogen bonds that keep an enzyme in its correct shape will weaken or break and the enzyme’s structure will change. This will in turn affect its function.

19. Describe the conditions inside the cell that enable enzymes to be active. Site evidence from the text to justify your answer.
Enzymes are only active at specific pH and temperature, thus an enzyme in a human cell, except in lysosomes, would be active at body temperature of 37 °C and at a pH of ~7.

20. Proteins with catalytic activity
What are enzymes?
Proteins with catalytic activity

21. Explain why enzymes are important to living things
Explain why enzymes are important to living things. Support your answer with evidence from the text.
Enzymes are to speed up reactions so they are useful for an organism’s biological processes.

22. Look over vocabulary, notes, and any practice work
Be ready for a test on Tuesday over Chapter 2 Section 3 and 4 (macromolecules and enzymes)
Look over vocabulary, notes, and any practice work