CHAPTER 5.2 ENZYMES - Assessment

1.

Multiple Choice

5 mins

1 pt

The graph below shows how the activity of an enzyme changes over a range of pH values. Which of the following conclusions can be drawn from this graph?

The optimum pH of the enzyme is 6.6.

The optimum pH of the enzyme is 5.8

The enzyme’s activity continually increases as pH increases from 5.0 to 9.0

The enzyme’s activity is greater around pH of 8.0 than around pH of 5.0.

2.

Multiple Choice

5 mins

1 pt

The diagram below illustrates a biochemical process that occurs in organisms. What is another name for the substance labeled "catalyst"?

Enzyme

inorganic compound

Hormone

Antibody

3.

Multiple Choice

5 mins

1 pt

Which of the following best explains why enzymes are necessary for many cellular reactions?

Enzymes supply the oxygen necessary for the reactions

Enzymes change reactants from solid to liquids during the reactions.

The reactions take up too much space in the cell if the enzymes are missing.

The reactions are too slow to meet the needs of the cell if enzymes are missing.

4.

Multiple Choice

5 mins

1 pt

What will most likely happen if an appropriate enzyme is added to a chemical reaction?

The reaction rate will increase.

The equilibrium of the reaction will be maintained.

The reaction rate will decrease.

The reaction will stop.

5.

Multiple Choice

5 mins

1 pt

The enzyme lactase will break down the sugar lactose into which of the following components?

monosaccharides

nucleic acids

amino acids

phospholipids

6.

Multiple Choice

5 mins

1 pt

Enzymes are an example of

Lipids

Carbohydrate

Protein

Nucleic Acid

7.

Multiple Choice

5 mins

1 pt

What is the purpose of an enzyme?

give permission for the reaction

raise activation energy

speed up reactions

control how many reactions occur

8.

Multiple Choice

5 mins

1 pt

Enzymes are capable of increasing the rate of a chemical reaction within a living cell. Enzymes accomplish this through which of the following means?

reducing the number of products

reducing the activation energy

increasing the temperature of the cell

increasing the concentration of reactants

9.

Multiple Choice

5 mins

1 pt

Each enzyme only has 1 substrate that will fit its active site. What is this called?

reusable

catalyst

specific

fragile

10.

Multiple Choice

5 mins

1 pt

What 3 letters do enzymes typically end in?

-ose

-ase

-ese

-tic

11.

Multiple Choice

5 mins

1 pt

After the enzyme and substrate bind together and perform the reaction, what does the substrate become?

a substrate

an enzyme

a product

an active site

12.

Multiple Choice

5 mins

1 pt

In the diagram, what is letter A?

product

substrate

enzyme-substrate complex

active site

13.

Multiple Choice

5 mins

1 pt

Letter D...

active site

enzyme

substrate

products

14.

Multiple Choice

5 mins

1 pt

Letter B...

active site

enzyme

substrate

products

15.

Multiple Choice

5 mins

1 pt

Letter C...

active site

enzymes

substrate

products

16.

Multiple Choice

5 mins

1 pt

Letter E...

active site

enzyme

substrate

products

17.

Multiple Choice

5 mins

1 pt

Enzymes provide a site where reactants called substrates can be brought together in an enzyme-catalyzed reaction. The site is called the

enzyme substrate complex.

reaction site.

active site.

lock and key.

18.

Multiple Choice

5 mins

1 pt

Chemical reactions always involve

the breaking of bonds in reactants.

the formation of new bonds in products.

the breaking of bonds in reactants and the formation of new bonds in products.

enzymes.

19.

Multiple Choice

5 mins

1 pt

An enzyme speeds up a reaction by

lowering the activation energy.

raising the activation energy.

releasing energy.

absorbing energy.

20.

Multiple Choice

5 mins

1 pt

Based on the graph, what is the optimal temperature for this enzyme?

15^oC

40^oC

30^oC

35^oC

21.

Multiple Choice

5 mins

12 pts

What happens when enzymes are heated to a high temperature?

The enzymes die.

The shapes of the enzyme are altered denature

The enzymes' amino acid sequence changes.

The enzymes remain the same

22.

Multiple Choice

5 mins

1 pt

Enzymes are composed of which of the following monomers?

amino acids

carbohydrates

nucleotides

monosaccharides

23.

Multiple Choice

5 mins

1 pt

Molecules that bind to enzymes and enhance an enzyme's ability are called:

CoFactors

CoEnzymes

Allosteric Inhibitors

Allosteric Activators

24.

Multiple Select

5 mins

1 pt

What can affect enzyme ability? (select all that apply)

temperature

inhibitors

pH

enzyme potential

25.

Multiple Choice

5 mins

1 pt

The ____________________ mechanism describes how each substrate must fit into the enzyme.

lock and key

hammer and nail

jigsaw puzzle

seesaw

26.

Multiple Choice

5 mins

1 pt

Why do enzymes denature?

It changes the shape of the active site.

Substrates move ineffectively in different temperatures/pH etc.

You need to go on a detox cleanse

The substrates change shape.

27.

Multiple Choice

5 mins

1 pt

What does optimum mean?

The conditions in which reactions occur badly

The conditions in which reactions occur well enough

The conditions in which reactions occur the best

The conditions in which reactions occur the worst

28.

Multiple Choice

5 mins

1 pt

Y is the enzyme that catalyses the hydrolysis of sucrose into glucose and fructose. What is enzyme Y?

Maltase

Lactase

Cellulase

Sucrase

29.

Multiple Choice

5 mins

1 pt

When the temperature increases, the rate of reaction between enzymes and substrates increases. What causes the rate of reaction to increase?

This is due to increase in activation energy required to break the chemical bond

This due to increase in the frequency of effective collision between the substrate molecules and enzyme molecules

This due to decrease in the frequency of effective collision between the substrate molecules and enzyme molecules

This is due to increase in temperature more than optimum temperature

30.

Multiple Choice

5 mins

1 pt

Why the rate of reaction is constant as the number of substrate increases?

due to the concentration of substrate becomes a limiting factor

all active sites of enzymes are saturated with substrate and are involved in the catalytic reaction

all active sites of enzymes are not saturated with substrate and are not involved in the catalytic reaction

due to the concentration of enzyme that becomes a non-limiting factor

31.

Multiple Choice

5 mins

1 pt

The enzyme activity is influenced by the pH of the surrounding solution. Generally, all enzymes react most effectively at their optimal pH.

Why enzyme-substrate complex cannot be formed when the enzyme is placed in different pH solution?

The change in pH value changes the charge (ion H+) of the active site of enzymes and the substrate surface

The change in pH value changes the shape of the active site of enzymes and the substrate surface

The change in pH value changes the size of the active site of enzymes and the substrate surface

32.

Multiple Choice

5 mins

1 pt

What is the method to increase the rate of reaction at number 2?

increase the number of substrate concentration

increase the number of enzyme concentration

decrease the number of substrate concentration

decrease the number of enzyme concentration

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