Biomolecule & Enzyme Study Guide
Chemical Reactions
Carbon Compound
Indicator used
Positive Test
Sugar
Starch
Protein
Lipid
Benedict’s solution
Iodine
Biuret’s solution
Brown Paper Bag
Sudan IV
Orange/Brick Red
Black
Purple
Translucent Spot
Red
Left
Right
Types of Reactions:
“LOCK AND KEY” MODEL OF ENZYME ACTION
There are four steps in the process of an enzyme working.
(1) An enzyme and a SUBSTRATE (key) are in the same area.
The substrate is the biological molecule that the enzyme will work
on.
(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.
(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. Big idea - 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.
Enzyme Activity
Lowers Activation Energy
Enzymes are proteins which are made of amino
acids.
Enzyme
Ends
in
-ase
3 things that affect enzyme activity:
1. Temperature (denatures)
2. pH (denatures)
3. Concentrate (amount) of substrate
Substrate
Biomolecule & Enzyme Study Guide
Carbon Compound
Indicator used
Positive Test
Sugar
Starch
Biuret’s solution
Translucent Spot
Sudan IV
1. What are the two parts to chemical reactions? ______________________ & __________________
2. All enzymes are what kind of biomolecules? _________________________________________
3. What does the active site on an enzyme match up to? ________________________________________
4. The process of enzyme activity starts with an _____________ ______________ on an enzyme that finds a
________________ in the cell. Then they combine to create an ________________ ____________________
____________________ where the enzyme changes the ____________________ but the enzyme (does or does
not) change. The enzyme releases the changed substance which is now called a ____________________.
5. In an enzymatic reaction the ___________ ______________ of the enzyme is like a lock and the
________________ is like a key.
6. Name three things that will regulate enzyme activity. Put a star beside the two that can denature the enzyme.
a. ____________________________________
b. ____________________________________
c. ____________________________________
7. When temperatures increase above the optimum, enzymes will begin to break down or ___________________.
8. Answer the following questions about the graph to the right:
a. What are A & B? _______________________________
b. What is C? ____________________________________
c. Is the reaction endothermic or exothermic? ___________
d. Draw a dotted line representing what would happen if an
enzyme were added to the reaction on the right.
9. Enzymes (raise or lower) the activation energy which causes the reaction to happen (faster or slower). Circle a
choice for each parenthesis option.
Experiments were designed to study the pH on the rate of the reaction for two different enzymes in animals, Enzyme
A and Enzyme B. Enzyme A is found in the stomach and digests meats. Enzyme B is found in the intestines and
digests fats. Look at the graph and answer the following questions.
10. At which pH does Enzyme A work the best? __________________
11. Since Enzyme A is found in the stomach, what is the probable pH of the stomach? ______________
12. At which pH does Enzyme B work the best? __________________
13. Since Enzyme B is found in the intestines, what is the probable pH of the intestines? _______________
14. If Enzyme A were produced in the intestine, would this enzyme still carry out its usual function? Yes or No.
Explain your answer below.
15. What type of reactions (endothermic or exothermic) are illustrated in the graphs below:
A
B
C
________________________
________________________
_______________________
16. Draw a reaction graph labeling the following: reactants, products, activation energy, course of the reaction, energy. Also
add in a dotted line to represent the addition of an enzyme and label it.