Download Bio A- Biochem Enzyme Note Packet Enzymes are a type of ___

Bio A- Biochem
Enzyme Note Packet
Enzymes are a type of ___ _____ meaning they are a folded chain of ____ ___.
In living things they act as ___ __________ which means: _________________________. ____ ____While they
_________________________________________________________________________________________________
Enzyme Reaction: Label the parts
Enzymes are needed for ALL chemical reactions that happen in the body including our two favorites _____ _________
and ______ ___________.
HYDROLYSIS
DEHYDRATION SYNTHESIS
Bio A- Biochem
How do enzymes work:
Enzymes are made by our cells.
By making it easier for substrates to react, enzymes lower the Activation energy of the chemical reaction
-
Activation energy:
o
think of it as the “energy cost” of the reaction
o
the enzyme is a “coupon”
Endothermic (endergonic
.
Exothermic(exergonic):
Bio A- Biochem
Example of an enzymatic reaction (sucrose)
Enzymes have very particular tastes!
Enzymes exhibit specificity
Look at the examples in your notes. In each case, the enzyme exhibits specificity
The enzyme and substrate fit together like jigsaw puzzle pieces. One type of reaction and one substrate for each enzyme
Lock and Key Model –
Induced fit model
Bio A- Biochem
What is the active site?
WHAT IMPACTS ENZYMES?
Not only are enzymes picky about what substrates they work with, but also the following conditions:
1.
Each enzyme has an optimal (“best”) temperature: ___
2. Each enzyme has an optimal pH.
a. pH is?
b. changing the concentration of H+ (pH is NOT in the optimal range) interferes with the bonds holding the
protein in its folded shape.
RESULT: ____________________________
BOTH temperature and pH will change the 3D shape of the protein, usually unfolding it.
o
Denaturation: the process of unfolding the 3D shape of a protein. DOES not disrupt the chain of amino
acids, just how it is folded.
 MAY be reversible if conditions are returned to optimal levels.
 Prevents the enzyme from working. NO product will form
ENZYMES HAVE A “BEST RANGE” that depends on their environment
WHAT ELSE AFFECTS HOW FAST AN ENZYME WORKS?
Bio A- Biochem
1, Rate of a reaction is also determined by the ratio of substrate to enzyme:
What is it telling us?
That the product will form faster as the amount of
substrate increases, but only up to a point (about 30 in
this example)
Why does this happen?
’
HERE IS ANOTHER WAY TO THINK ABOUT THE GRAPH: Notice that the enzyme amount stays the same.
Lots of enzyme little substrate
Equal enzyme and substrate
Lots more substrate than enzyme
Some enzymes need “helper” molecules
-
Coenzyme: organic molecules (like vitamins) that help a substrate bind to its enzyme
o Organic means??? _CONTAINS C and H (and since it is found in living things..Oxygen! _____
Cofactors: inorganic molecules (like Zn, Cu) that help a substrate bind to its enzyme
Both coenzymes and cofactors bind to the enzyme and improve chances that the substrate will bind.
Label the parts of this diagram
Bio A- Biochem
Inhibiting an enzyme
•
Inhibit: shut down or suppress
•
Can be caused by outside molecule – drugs/poisons
•
Can be caused by inside molecule if your body wants to temporarily shut down a reaction
–
Why waste the energy if you don’t need the product right now?
•
Competitive Inhibition– molecules that are similar in shape to the substrate bind to the active site and block the
substrate; No chemical reaction can happen
•
Non-competitive Inhibition– molecule different from the substrate binds to a part of the enzyme other than the
active site and alters the shape of the active site; No chemical reaction