1. ENZYME PRACTICE TEST
Push F5 and use the arrow keys to quiz yourself
and check the answers

2. 1

Enzymes are what type of macromolecule?

Protein
Question… do you know all four types of
macromolecules?
 Protein, lipid, nucleic acid, and carbohydrate


3. 2

Starch and sugar (monosaccharides) are both
examples of what type of macromolecule?

Carbohydrate

4. 3

How do we test for starch? What do the negative
and positive results look like?
We use iodine to test for starch
 Negative = brown
 Positive = purple


5. 4

How do we test for sugars? What do the negative
and positive results look like?
We use Benedict’s Solution to test for starch
 Negative = clear blue
 Positive = cloudy and a color change


6. 5

What monomers is a starch molecule made of?

Starch is made of many glucose molecules bonded
together in a long chain

7. 6

What does the enzyme amylase do?

Amylase breaks a starch molecule up into the
individual glucose monomers

See the next slide for a visual representation of
this process

9. 7

If you were to leave starch in your mouth and
mix with the amylase in your saliva, how would
the food taste after 5 minutes? Why?
The food would taste sweet
 The amylase broke the bonds in the starch
molecules, so after a few minutes all you’d be left
with is glucose, which is a sugar


If this is totally blowing your mind, go back to
the previous slide and think about it. Or try
doing it yourself and see how it goes 

10. 8

If you were to put catalase into a beaker of starch
solution, what would happen? WHY?
Nothing would happen!
 Enzymes are specific. Like a lock and a key, they
only work on the reaction that includes
substrates that fit their specific shape.
 Catalase is only able to react with hydrogen
peroxide- it has the wrong shape for starch
 So, catalase is not able to break down starch
molecuels


11. 9

What is a catalyst?
A catalyst is anything that speeds up a reaction
 Enzymes are a type of catalyst
 If something is said to be catalyzed, it means the
reaction was sped up by something
 For example, the hydrolysis of starch is catalyzed
by the enzyme called amylase


12. 10

Write the chemical formula for the reaction
catalyzed by the enzyme catalase. Do it in words
AND in chemical formulas
Hydrogen Peroxide  Water + Oxygen
 HO  HO + O
2 2
2
2


13. 11

In a chemical reaction, what are the reactants?

Reactants are the things you start with in a
chemical reaction

H2O2  H2O + O2

14. 12

In a chemical reaction, what are the products?

Reactants are the things you end up with in a
chemical reaction

H2O2  H2O + O2

15. 13

In enzyme catalyzed reactions, reactants have a
special name. What is the special name?

Substrates

In enzyme-catalyzed reactions, the word reactant
and substrate means the same thing

H2O2  H2O + O2 In this case, the hydrogen
peroxide can be called a substrate

16. 14

When a potato is dropped into hydrogen peroxide,
bubbles start to form. What are those bubbles?

O2 or oxygen gas

17. 15

When a potato is dropped into hydrogen peroxide,
bubbles start to form. What liquid would be
leftover in the beaker if this reaction were to go
to completion?

Water

18. 16

What does excessive heat do to an enzyme?
Since enzymes are proteins, high temperatures
cause the shape to change
 When the shape changes, the enzyme doesn’t
function correctly anymore


19. 17

What is activation energy?

Activation energy is the amount of energy needed
to get a reaction started

20. 18

How are enzymes able to speed up reactions?
Enzymes lower the amount of activation energy
needed to start a reaction
 Don’t be fooled! Enzymes don’t provide energy or
raw materials, they just provide a way for the
reaction to take place that needs less activation
energy.


21. 19

After an enzyme releases the products of the
reaction, what happens to the enzyme?
Nothing!
 Enzymes are like car keys- they can be used over
and over again (for the same car) as long as they
aren’t damaged
 The enzyme keeps it same shape and doesn’t get
used up, so it’s able to keep catalyzing the
reaction


22. 20

How would the starch and water solution
perform on these tests? Why?
It would test positive for starch and negative for
sugars
 Starch reacts with iodine so it tests positive for
starch. But, the Benedict’s test doesn’t react to
the glucose molecules because in starch, they’re
all stuck together

Solution
Starch and Water
Positive (+) or Negative (-)
for Starch
Positive (+) or Negative (-)
for Simple Sugars

23. 21

How would a solution of starch, water, and
amylase perform on these tests? Why?
It would test negative for starch and positive for
sugars
 The amylase breaks the bonds in the starch
molecule, leaving only sugars. Therefore, it will
no longer test positive for starch but the
Benedict’s test will test positive for the sugars

Solution
Starch Water and Amylase
Positive (+) or Negative (-)
for Starch
Positive (+) or Negative (-)
for Simple Sugars

24. 22

What molecule is this?
This is a starch molecule
 It is made up of many glucose molecules bonded
together
 I know those are glucose molecules because
glucose has six carbons, and therefore it has six
sides (hexagon)


25. 23

When a student drops a piece of potato into a
beaker of hydrogen peroxide, bubbles start to
form. What was in the potato that made this
happen?

The potato cells contain an enzyme called
catalase.

26. 23

Is this graph indicative of how enzymes react to
different pH levels or concentration levels? How do
you know?

This is what happens in different pH levels.
Low and high pH levels cause the shape of the
enzyme to change, therefore it doesn’t work correctly
anymore and the activity level goes down.


27. 24

Is this graph indicative of how enzymes react to
different temperatures or concentration levels? How
do you know?

Different concentration levels
Increasing the concentration causes the activity to go
up at first. But once you reach a certain point, there
are already enough helpers (enzyme molecules) to
handle the substrates that are there


28. 25

Is this graph indicative of how enzymes react to
different temperatures or concentration levels? How
do you know?

This is what happens in at different temperatures
High temperatures cause the shape of the enzyme to
change, therefore it doesn’t work correctly anymore
and the activity level goes down.
Low temperatures cause reactions to take place more
slowly, whether there is an enzyme present or not

