1. Why are enzymes important to living things?

2. Catalysts
Some chemical reactions require a temperature so high it would be impossible in a biological system without some help.
A catalyst is a chemical that lowers the activation energy necessary for a reaction to occur.
A catalyst can also speed up how quickly the reaction occurs.
A catalyst is able to be recycled, so the catalyst can be used over and over.
In the body, these catalysts are called enzymes.

3. Enzymes Enzymes are made of proteins. They are biological catalysts.
They speed up reactions that occur in cells and lower the energy necessary for the reaction.

4. The ending –ase means its an enzyme!
Enzymes
Enzymes are VERY specific, they can only help one type of chemical reaction. (so.. Every chemical reaction has to have their OWN enzyme!)
Since enzymes are SO specific, they are named according to what reaction they help.
Ex:
- hydrase – breaks down hydrogen
Carbonic anhydrase – breaks down carbonic acid
oxidase – breaks down oxygen
lactase -
The ending –ase means its an enzyme!

5. Four steps in the process of an enzyme working:
1. An enzyme and a substrate are in the same area.
The substrate is the biological molecule that the enzyme will attack.
2. The enzyme grabs onto the substrate with a special area called the active site.
The active site is a specially shaped area of the enzyme that fits around the substrate.
The active site is the keyhole of the lock.
This combination is referred to the “Lock and Key Model of the Enzyme and Its Substrate” or the “Induced Fit Model”

6. 3. A process called catalysis happens.
Catalysis is when the substrate is changed.
It could be broken down or combined with another molecule to make something new.
4. The enzyme lets go.
When the enzyme lets go, it returns to normal, ready to do another reaction.
The substrate is no longer the same.
The substrate is now called the product.

7. CAN YOU STOP THEM?
There are many factors that can regulate enzyme activity, including temperature, activators, pH levels, and inhibitors.
Irreversible inhibition occurs when the inhibitor added denatures or destroys the enzyme.
Reversible inhibition can be competitive or noncompetitive.
In competitive inhibition, the inhibitor competes with the substrate for the same binding site on the enzyme.
In noncompetitive inhibition the inhibitor temporarily binds to a site other than the binding site. If the enzyme is an allosteric enzyme, the presence of the inhibitor changes the shape of the enzyme and prevents the reaction from occurring.

8. Many factors influence enzyme function:
Different enzymes function better at different pHs.
Enzymes in your stomach may prefer an acidic environment with a low pH while enzymes elsewhere may not.
In general, higher temperatures speed reactions -- to a point.
Above 1040F, enzymes become denatured and can no longer catalyze reactions.
Higher concentrations of substrate also speed reactions until the solution reaches a saturation point.
- Past that point, the addition of substrate will not affect the velocity of the reaction.

9. Resources: http://www.biologycorner.com/bio3/notes-enzymes.html