1. Do Now Hand in Yesterday’s challenge sheet
Amino acid is to protein as:
-fat is to lipid
-DNA is to RNA
-Sugar is to fat
-Glucose is to carbohydrate
Which of the following is not a monomer?
-glucose molecule
-amino acid
-nucleotide
-protein

2. Do Now Continued Which statement is true about macromolecules?
Simple sugars are made of polysaccharides
Glycerol is made of fatty acids
Proteins are made of amino acids
Nucleotides are made of nucleic acids

3. 2.4 Chemical Reactions and Enzymes
Lesson Overview
2.4 Chemical Reactions and Enzymes

4. Chemical Reactions
A chemical reaction = process that changes one set of chemicals into another by breaking and making bonds.
Reactants - elements or compounds that enter into a chemical rxn.
Products - elements or compounds made.

5. Chemical Reactions CO2 + H2O ---> H2CO3
This rxn allows blood to carry CO2 to the lungs.

6. Energy Changes When a bond is formed - energy is absorbed.
When a bond is broken - energy is released.

7. Activation Energy
The energy that is needed to get a reaction started is called the activation energy.

8. ENZYMES - Nature’s Catalysts
Enzymes = proteins that act as biological catalysts
They speed up chemical reactions in cells.
Enzymes lower the activation energy!!!!!!

9. The Enzyme-Substrate Complex
The reactants of an enzyme = substrates.
enzyme = carbonic anhydrase substrates = CO2 and H2O products = carbonic acid (H2CO3).

10. The Enzyme-Substrate Complex
The substrates binds to the active site.
The active site and the substrates have the same shapes.
The fit is so precise that the active site and substrates are often compared to a lock and key.

11. Regulation of Enzyme Activity
Factors that affect how an enzyme works:
- Temperature:
Too high - the enzyme breaks
Too low - the enzyme moves too slow
- pH:
Too low - the enzyme breaks
- regulatory molecules:
inhibitors - fit in active site, block the substrate.
co-enzymes – molecules that increase enzyme activity
Ex. Vitamins and minerals!

12. movie