2. Enzymes!

3. Proteins
Biological catalysts that speed up the rate of chemical reactions
They help make products faster!
Never used up!
“Matchmaker”
ENZYMES!!!

4. Enzymes in Action
Enzymes speed up chemical reactions that take place in cells
They DECREASE ACTIVATION ENRGY
The energy needed to get the reaction started (or energy needed to start making product)

5. break up hydrogen peroxide
Catal-ASE is an enzyme
that helps
break up hydrogen peroxide

6. Proteins: Enzymes What is a chemical reaction?
Do they happen on their own?
If we stare at the piece of paper, are we going to be able to make the oxygen molecules in the air collide with the cellulose in the paper?
What do we need to do?
What are reactants?
What are products?

8. Examples of endothermic reactions:
Melting of ice absorbs energy
Dissolving ammonium nitrate in water( the essence of commercial cold packs)
Examples of exothermic reactions:
Digestion of food releases energy
All combustion reactions (fires)
C + O2 CO2 + E
Adding an alkali metal to water
2 Na + 2 H2O 2 NaOH + H2 + E
Condensation of water
Explosion of bombs

9. Endothermic Reactions
the reactants have less potential energy than do the products. Energy must be input in order to raise the particles up to the higher energy level.
Energy + A + B --> AB

10. Exothermic Reactions
the reactants have more potential energy than the products have. The extra energy is released to the surroundings.
A + B --> AB + Energy

11. Enzymes Substrate Molecule/compound that attaches to enzyme
Catalyst
Anything that speeds up the rate of a reaction by lowering the ACTIVATION ENERGY
Activ. E: energy required for a chem. Rxn to start making products
used to regulate the rate (speed) of chemical reactions
Protein that helps speed up a reaction that occurs in a biological system
Name of enzymes end in –ASE
all enzymes are proteins, but not all proteins are enzymes
each chemical reaction in an organism requires its own specific enzyme
enzymes are never changed by their reactions!
Substrate
Molecule/compound that attaches to enzyme
Active Site
Specific location on enzyme for substrate to attach
Where the enzymatic reaction occurs
Enzyme-substrate complex
When substrate binds to active site of enzyme
Products
molecules produced at the end of an enzymatic reaction

12. Factors that Effect the Rate of Reactions
Temperature
Hot
Breaks bonds that give proteins its tertiary structure DENATURES
Cold
Slow down chemical reaction (formation of enzyme substrate complex) pH
Acids and bases produce OH- and H+ ions
too many ions are present, the enzyme may be denatured (twisted and pulled so out of shape that it can no longer function)
Inhibitors
Non-competitive
react with portions of the active site, changing of its shape
Allosteric Inhibitors
Change shape of the enzyme
Attach to regulatory site (not active site) and change the shape of the entire enzyme (specifically the active site)
Competitive
look like substrate, bind to active site, but do not make the intended product

14. Acetylcholinesterase
catalyzes the breakdown of the neurotransmitter acetylcholine at several types of synapses as well as at the neuromuscular junction — the specialized synapse that triggers the contraction of skeletal muscle.
One molecule of acetylcholinesterase breaks down 25,000 molecules of acetylcholine each second
makes possible the rapid "resetting" of the synapse for transmission of another nerve impulse.

16. Lock and Key Model

19. Class work! Label Each box!2. 3. 4. 1. 5.

20. 6.
Class Work! Label Boxes! 7. 8. 9.
10.