1.
The graph to the right represents the relationship between pH and
the rate of enzyme action for two enzymes, X and Y.
Which statement best describes this pattern of enzyme action?
a. As the pH increases from 2.5 to 3.5, the rate of action of enzyme X decreases.
b. At a pH of 5.5, the rate of action of enzyme X is the same as that of enzymeY.
c. As the pH increases from 10 to 11, the rate of action of enzyme Y increases.
d. At a pH of 7.0, the rate of action of enzyme Y is less than that of enzyme X.
2.
In nucleotides, the letters A, T, C, and G represent
a. phosphate groups.
b. deoxyribose sugars.
3.
c. ribose sugars.
d. nitrogenous bases.
Data Table
The results of an experiment to determine the chemical
composition of the cytoplasm of organism X are
summarized in the data table to the right. What percentage of
the cytoplasm is composed of organic material?
a. 100
b. 22
c. 20
d. 15
Substance
Water
Proteins
Fats
Carbohydrates
Mineral salts
% by mass in cytoplasm
77
15
5
2
1
Base your answers to questions 4-8 on the chart below and your knowledge of biology.
4.
Which molecule belongs in section G?
H-O-H
a.
5.
6.
b.
In what section of the chart do nucleic acids belong?
a. H
b. B
c. F
c.
d.
d. D
In what section of the chart do the substances starch and glycogen belong?
1
a. E
b. A
c. C
d. I
7.
Which class of substances has a monomer of an amino acid?
a. H
b. F
c. A
d. D
8.
What are some examples that could be in section I?
a. enzymes and antibodies
c. starch and glycogen
b. DNA and RNA
d. phospholipids and steroids
9.
____ is the energy storage compound found in animals and ___ is the energy storage compound of plants.
a. cellulose, starch
b. cellulose, glycogen
c. glycogen, starch
d. starch, glycogen
10.
A process that occurs in the human body is shown in the diagram below.
What would happen if the temperature would increase to 45C and cause the shape of the active site to be
altered?
a. The protein substrate would be broken down into two amino acids faster.
b. The amino acids would not combine at all.
c. The amino acids would combine faster.
d. The protein substrate would not be broken down into two amino acids.
Base your answers on questions 11-15 on the organic compounds represented below and your
knowledge of biology.
A.
D.
B.
C.
11.
Which compound represents the basic unit of both a DNA molecule and an RNA molecule?
a. A
b. B
c. C
d. D
12.
Which compound contains both an amine group and a carboxyl group?
a. A
b. B
c. C
d. D
13.
Which macromolecules are made up of repeating units of molecule D?
a. proteins and nucleic acids
c. fats and oils
b. hemoglobin and enzymes
d. starch and cellulose
Which food contains the highest percentage of the type of molecule represented by C?
a. butter
b. bread
c. table sugar
d. lettuce
14.
15.
How many different elements are found in molecule C?
a. 37
b. 2
c. 3
d. 47
2
16.
Which of the following elements are the main components of every living cell?
a. carbon, hydrogen, nitrogen, sulfur, oxygen, iron
b. carbon, hydrogen, nitrogen, phosphate, sulfur, gold
c. carbon, hydrogen, nitrogen, oxygen, phosphate
d. carbon, hydrogen, nitrogen, sulfur, copper, lead
17.
Water can be released back into the environment through biotic processes by
a. condensation, respiration, transpiration, and decomposition.
b. respiration, ground runoff, perspiration, and urination.
c. transpiration,ground runoff, respiration, and decomposition.
d. decomposition, transpiration, respiration, and perspiration.
18.
Which organisms break down chemical substance in the environment, making these substances
available for use by other organisms?
a. producers
b. decomposers
c. herbivores
d. carnivores
19.
Which statement best describes the enzyme represented in the graphs below?
a.
b.
c.
d.
This enzyme works best at a temperature of 50 oC and a pH of 12.
This enzyme works best at a temperature of 35 oC and a pH of 8.
Temperature and pH have no effect on the action of this enzyme.
This enzyme works best at a temperature above 50 oC and a pH above 12.
Use the graph to the right to answer questions 20 and 21.
20.
Based on the graph, what can you conclude about the
relationship between enzyme concentration and reaction rate?
a. The variables are indirectly proportional.
b. Reaction rate increases with decreasing enzyme concentration.
c. The reaction rate increases with increasing enzyme concentration.
d. The variables are not related.
21.
Which concentration of catalase will produce the fastest reaction rate?
a. 20%
b. 10%
c. 5%
d. 0%
22.
Which of the following organic compounds is the main source of energy for living things?
a. lipids
b. nucleic acids
c. carbohydrates
d. proteins
23.
This graph to the right shows that
a. pepsin is less effective at low pH than trypsin.
b. trypsin is not effective at a high pH.
c. pH affects the activity rate of enzymes differently.
d. more enzymes are present at a higher pH.
3
24.
Enzymes affect the reactions in living cells by changing the
a. speed of the reaction.
c. temperature of the reaction.
b. products of the reactions.
d. pH of the reaction.
Label 26-30 as describing one of the choices below. Read each description carefully.
26. includes the bases A,T,G,C
27. contains nucleotides
28. is responsible for controlling cellular activities and heredity
29. contains the sugar ribose
30. single stranded
a) RNA
b) DNA
c) Both
Given the reactions below (31-34) that occur with the addition of the following chemicals, match the correct
substance that each contains.
31. when benedict solution was added the solution turned green or orange
32. when iodine was added the substance turned black
33. when biuret solution was added the solution turned purple
34. when the substance rubbed on brown paper; paper was translucent
a. glucose
b. starch
c. lipid
d. protein
CLE 3210.1.2 Distinguish among the structure and function of the four major organic
macromolecules found in living things.
1. Proteins are large macromolecules composed of thousands of subunits. The structure of the
protein depends on the sequence of
A
lipids.
B
glycerols.
C
amino acids.
D
monosaccharides.
2. Part of a laboratory procedure is shown in the diagram below.
This setup would most likely be involved in a procedure to
A
test for the presence of glucose using an indicator.
B
stain specimens while making a wet mount.
C
separate pigments in a mixture.
D
determine the pH of solutions.
3. Analysis of DNA from a frog and a bacterium would reveal that
A
DNA from both organisms is composed of repeating nucleotide units.
B
frog DNA is single stranded, but bacterial and is double stranded.
C
frog DNA contains thymine, but bacterial DNA contains uracil.
D
DNA from both organisms contains the sugar ribose.
4
4. Which of the following categories of organic molecules is correctly paired with one of its
functions?
A
nucleic acids—digest dead cells
B
lipids—give quick energy to cells
C
carbohydrates—store genetic information
D
proteins—provide structure in skin, hair, and nails
5. When lactose, the sugar in milk, is digested by the human body, each lactose molecule is
broken down into smaller molecules. To which of the following categories of molecules do these
smaller molecules belong?
A
amino acids
B
nucleic acids
C
polypeptides
D
monosaccharides
6. A protein molecule which is denatured, has
A
combined with another molecule.
B
split into smaller molecules.
C
changed its shape.
D
been diluted.
7. When an animal has to survive without food for a long time, it will eventually break down
proteins for energy. However, this process occurs only after exhausting the animal’s reserves of
A
DNA and RNA.
B
carbohydrates and lipids.
C
carbon dioxide and water.
D
enzymes and nucleic acids.
8. Lemurs’ bodies are adapted to efficiently store energy for times when food is scarce. This
adaptation may help to explain how lemur ancestors survived the trip across the Mozambique
Channel from mainland Africa to Madagascar. Which of the following types of molecules are
primarily used for long-term energy storage in the lemur?
A
monosaccharides
B
nucleic acids
C
proteins
D
lipids
9. In the human body, fibrinogen is necessary for sealing cuts and stopping the loss of blood.
Since fibrinogen is made of chains of amino acids, it is an example of which type of organic
molecule?
A
protein
B
fatty acid
C
nucleic acid
D
carbohydrate
5
10. Carbohydrates and proteins are two types of macromolecules. Which functional
characteristic of carbohydrates distinguishes them from proteins?
A
large amount of stored information
B
ability to catalyze biochemical reactions
C
efficient storage of usable chemical energy
D
tendency to make cell membranes hydrophobic
CLE 3210.1.3 Describe how enzymes regulate chemical reactions in the body.
1. What causes tomatoes to ripen much more slowly in a refrigerator than they do if left on a
table at room temperature?
A
Tomatoes need sunlight to ripen.
B
Humidity accelerates the ripening process.
C
Enzymes produced by bacteria inhibit ripening.
D
Low temperatures reduce the action of ripening enzymes.
2. There are many different enzymes located in the cytoplasm of a single cell. How is a specific
enzyme able to catalyze a specific reaction?
A
Most enzymes can catalyze many different reactions.
B
Different enzymes are synthesized in specific areas of the cytoplasm.
C
Enzymes are transported to specific substrates (reactants) by ribosomes.
D
An enzyme binds to a specific substrate (reactant) for the reaction catalyzed.
3. Some snake venoms are harmful because they contain enzymes that destroy blood cells or
tissues. The damage caused by such a snakebite could best be slowed by
A
inducing vomiting.
B
applying ice to the bite area.
C
drinking large amounts of water.
D
increasing blood flow to the area.
4. Maltose can be broken down into glucose molecules by the enzyme maltase. Which of the
following would slow the reaction rate?
A
adding maltase
B
adding maltose
C
removing glucose
D
diluting with water
6
5. The graph below shows the effect of substrate concentration on the action of enzyme X. This
enzyme is functioning at its optimal temperature, 36°C, and at its optimal pH, 5.5.
6. When the substrate concentration increases from 0.4% to 0.5%, the rate of the reaction
A
decreases.
B
increases.
C
remains the same.
D
increases, then decreases.
7. The reaction catalyzed by the bacterial enzyme, ß-galactosidase, forms a dark-colored endproduct when the cells are grown on a particular agar medium. As more product is formed, the
cells become darker. Students performed an experiment to determine the optimum pH for
activity of this enzyme. Their results are shown in the illustration of bacterial colonies below.
Based on these data, the students should conclude that ß-galactosidase functions best at which
pH?
A
pH 5
B
pH 7 *
C
pH 9
D
pH 11
8. Some bacteria contain a substance called nitrogenase. Nitrogenase catalyzes the chemical
reaction that converts atmospheric nitrogen (N2) into ammonia (NH3). Nitrogenase is an
example of which of the following?
A
a sugar
B
an enzyme
C
a nucleotide
D
an amino acid
7
9. What occurs during the digestion of starch?
A
Specific enzymes break down starch into amino acids.
B
Specific enzymes break down starch into simple sugars.
C
Specific hormones break down starch into simple sugars.
D
Specific hormones break down starch into complex starches.
10. A protein-digesting enzyme when mixed with starch solution would
A
have no action.
B
produce glucose.
C
digest the starch.
D
produce amino acids.
11. Which of the following best explains why enzymes are necessary for many cellular
reactions?
A
Enzymes supply the oxygen necessary for the reactions.
B
Enzymes change reactants from solid to liquid during the reactions.
C
The reactions take up too much space in the cell if enzymes are missing.
D
The reactions are too slow to meet the needs of the cell if enzymes are missing.
12. The clear protein of an egg white becomes opaque and firm when cooked because the heat
A
mutates the DNA.
B
stops protein formation.
C
changes the protein structure.
D
turns the protein into carbohydrates.
13. Which statement describes all enzymes?
A
They control the transport of materials.
B
They affect the rate of chemical reactions.
C
They absorb oxygen from the environment.
D
They provide energy for chemical reactions.
14. In red blood cells, the compound carbonic anhydrase increases the rate at which carbon
dioxide is converted to bicarbonate ions for transport in the blood. In red blood cells, carbonic
anhydrase acts as which of the following?
A
a lipid
B
a sugar
C
a hormone
D
an enzyme
15. Some bacteria live in hot springs. Their cells contain enzymes that function best at
temperatures of 70°C or higher. At a temperature of 50°C, how will the enzymes in these
bacterial cells most likely be affected?
A
The enzymes will be destroyed by lysosomes.
B
The enzymes will lose their bond structure and fall apart.
C
The enzymes will require less energy to function than at 70°C.
D
The enzymes will not increase the rate of reactions as much as they would at 70°C.
8
16. The diagram below represents a series of reactions that can occur in an organism.
This diagram best illustrates the relationship between
A
ribosomes and sugars.
B
antigens and immunity.
C
enzymes and synthesis.
D
amino acids and glucose.
17. How are enzymes best able to work with specific substrates?
A
Each substrate destroys its specific enzyme.
B
An enzyme actively interferes with other substrates around it.
C
An enzyme can only use a specific ionic bond with the substrate.
D
Each substrate has a specific activation site for enzyme attachment. _
18. What is the function of enzymes in biological systems?
A
Enzymes act as products to create new chemical reactions.
B
Enzymes act as catalysts to drive chemical reactions forward.
C
Enzymes bond with substrates to create the new reaction products.
D
Enzymes act as substrates when the necessary proteins are unavailable.
9
19. Read the passage below.
Rate of Chemical
Reaction
Temperature
4.
Temperature
Rate of Chemical
Reaction
2.
3.
Rate of Chemical
Reaction
1.
Rate of Chemical
Reaction
In the human body, the enzyme pepsin helps break down
proteins to amino acids. Pepsin is most effective around
37°C. A student plans to conduct an experiment by placing
the same amount of pepsin in beakers containing a protein
solution that is at various temperatures ranging from 10°C
to 50°C.
Temperature
Which graph best illustrates the expected results for this investigation?
A
graph 1
B
graph 2
C
graph 3
D
graph 4
20. Read the passage then answer the question.
Harry’s doctor prescribes an antibiotic for his sinus infection. After
taking one dose of the antibiotic, Harry develops diarrhea causing the
pH in his small intestine to be lowered. Trypsin, an enzyme that
completes protein digestion in the small intestine, has an optimum pH
range of 7 – 9.
Which of the following most likely happens to the enzymes in Harry’s intestine?
A
The enzyme becomes inactive.
B
The enzyme begins to replicate.
C
The enzyme’s shape changes to engulf large proteins.
D
The enzyme’s activity increases to digest more proteins.
10
21. How do reactions without enzymes differ from reactions with enzymes present? Select two
options.
A
The reaction occurs at a much slower rate.
B
The reaction requires the presence of catalysts.
C
The reaction changes the shape of the catalysts.
D
The reaction happens at much lower temperatures.
E
The reaction requires a higher amount of activation energy.
F
The reaction changes the pH of the surrounding environment.
SPI 3210.1.5 Identify how enzymes control chemical reactions in the body.
Study the graph below.
1. Which of the following might cause a decrease in the rate of reaction beyond point C?
A
a change in pH
B
addition of an inhibitor
C
addition of more substrate
D
a decrease in temperature
E
addition of water molecules
F
addition of more enzyme molecules
2. In what way could you increase the rate of reaction taking place in the image shown?
A
B
C
D
alter the active site
add more substrate
add more water molecules
add more enzyme molecules
11
3. The graph shows how the activity of an enzyme changes at different temperatures.
Which statement best describes what happens to the enzyme when the temperature of the
reaction increases to 63 degrees C?
A
The enzyme is used up and the reaction stops.
B
The enzyme begins to decrease the rate of the reaction.
C
The enzyme continues to increase the rate of the reaction.
D
The enzyme changes shape and can no longer speed up the reaction.
12