1. Enzymes Review Day

2. Terms from last POGIL “gonic” Reactions
Biology, Sixth Edition Chapter 6, Energy and Metabolism
“gonic” Reactions
Reactions that require energy input are called endergonic
if they need heat, they are endothermic
If a reaction releases energy it is exergonic
if the energy is released as heat, it’s exothermic.
Terms from last POGIL

3. ATP Adenosine triphosphate It is a nucleotide 3 parts
Nitrogen base (adenine)
Ribose (5C sugar)
3 phosphate groups
Energy of ATP is in these bonds
Hydrolysis (adding water) breaks this bond making ADP + Pi
This is called phosphorylation
Biology, Sixth Edition Chapter 6, Energy and Metabolism

4. Energy Released by the Hydrolysis of ATP is Coupled to Other Reactions
Biology, Sixth Edition Chapter 6, Energy and Metabolism

5. NAD+ / NADH & Oxidation / Reduction Reactions
OilRig
NAD+ / NADH & Oxidation / Reduction Reactions
Reduction is the addition of electrons.
Results in increased energy content
Very common in metabolism
e.g., NAD NADH
e.g., FAD FADH2
Oxidation is the loss of electrons.
e.g., NADH NAD+
e.g., FADH FAD
Oxidation and reduction are often coupled as redox reactions.
Biology, Sixth Edition Chapter 6, Energy and Metabolism

6. Enzymes Lower EA
Activation energy (Ea) is the energy required to break the bonds to begin the reaction
Biology, Sixth Edition Chapter 6, Energy and Metabolism

7. Result?
Induced fit

8. Catalase AP Lab #2 Example of an enzyme (all enzymes end in ASE)
Is found in all living things
Used to break down toxins in the body
For example, Catalase breaks down hydrogen peroxide in the body (it is a byproduct of metabolism)
AP Lab #2

9. 3.4 Notes!
Having too little of an enzyme or having too much of an enzyme can have major consequences
Sucrase (lack of it causes diarrhea, cramps & possibly slower growth in kids)
Too much of an enzyme is wasteful for the cell
So in order to maintain homeostasis, we need to regulate enzymes!

10. Inhibitors
Chemicals
Some naturally occur in cells (can regulate metabolism)
Others are made in laboratories (used to treat diseases)
Inhibitors bind to enzymes, which has an effect on the function of an enzyme.

11. Competitive Inhibition
Inhibitor binds to the active site of an enzyme
Induced fit occurs and enzyme is unable to bind to substrate.
Reversible
When inhibitor is in low amounts, it will leave the active site and then the substrate can bind.

12. Allosteric inhibition
Inhibitor binds to an alternate site on the enzyme (not the active site), called the allosteric site.
Still changes shape of enzyme, so substrate cannot bind to active site
Also called noncompetitive inhibition

13. What can affect an enzyme?pH
Temperature
All enzymes have optimal conditions for optimal performance
Remember enzymes are proteins, so if the tertiary level is changed, the enzyme loses its function