AP Biology Exam Questions And Accurate
Answers 2024-2025
A genetic alteration in the gene coding for a specific single-polypeptide enzyme
substitutes an amino acid with a polar R group, serine, with the amino acid
phenylalanine that has a non-polar R group. When scientists test the catalysis of this
normal enzyme and the mutated enzyme, they observe that the mutated enzyme has
drastically lower activity compared to the normal enzyme. Which of the following is the
most likely explanation for how the amino acid substitution has resulted in decreased
catalytic activity by the mutated enzyme? A. The substitution decreased the mass of the
enzyme so that the mutated enzyme binds more weakly to the substrate than the normal
enzyme does.
B. The substitution altered the secondary and tertiary structure of the enzyme so that
the mutated enzyme folds into a different shape compared to the normal enzyme.
C. The substitution caused many copies of the mutated enzyme to aggregate together
and compete for subs - Answer B. The substitution changed the secondary and tertiary
structure of the enzyme so that the mutated enzyme folds into a different shape than the
normal enzyme does.
An average bag of fertilizer contains large quantities of nitrogen, phosphorus, and
potassium and only trace amounts of magnesium and calcium. Which of the following
most accurately reflects the fertilizer component to the molecule it will be incorporated
by the organisms in the area?
A. Nitrogen will be incorporated into nucleic acids
B. Phosphorus will be incorporated into amino acids
C. Potassium will be incorporated into lipids
D. Magnesium will be incorporated into carbohydrates -Answer A. Nitrogen will be
incorporated into nucleic acids
Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen
synthase is one of the enzymes responsible for converting carbohydrate monomers into
polymers. Which of the following best describes the reactions of these enzymes?
A. Amylase acids in the removal of a water molecule to break covalent bonds whereas
glycogen synthase aids in the addition of a water molecule to form a covalent bonds.
, B. Amylase aids in the addition of a water molecule to break covalent bonds whereas
glycogen synthase aids in the removal of a water molecule to form covalent bonds.
C. Amylase catalyzes the addition of a water molecule to form covalent bonds whereas
glycogen synthase catalyzes
the removal of a water molecule to break covalent bonds
D. Amylase catalyzes the removal of a water molecule to form covalent bonds whereas
glycogen synthase catalyzes
the addition of a water molecule to break covalent bonds. - Answer B. Amylase
catalyzes the addition of a water molecule to break covalent bonds whereas glycogen
synthase catalyzes the removal of a water molecule to form covalent bonds.
A researcher measured the temperature at which two different samples of
double-stranded denature
(separate into single strands). Sample denatured at a much lower temperature
compared to sample.
Based on these data, the researcher claims that the in sample contains a higher
percentage of
guanine and cytosine than does the in sample.
Which of the following is the best evidence for the researcher's conclusion?
A. The bonds between guanine and cytosine are covalent bonds, which take more
energy to break than
do those between adenine and thymine.
B. Guanine-cytosine pairs denature at a higher temperature because they have more
hydrogen bonds between
them than adenine-thymine pairs do.
C.Adenine-thymine pairs require less energy to separate because adenine and thymine
are both singlering
bases.
D. Guanine-cytosine pairs require more energy to separate because one is a purine and
one is a pyrimidine. - Answer B. Guanine-cytosine pairs denature at a higher
temperature because they have more hydrogen bonds between
them than adenine-thymine pairs do.
Answers 2024-2025
A genetic alteration in the gene coding for a specific single-polypeptide enzyme
substitutes an amino acid with a polar R group, serine, with the amino acid
phenylalanine that has a non-polar R group. When scientists test the catalysis of this
normal enzyme and the mutated enzyme, they observe that the mutated enzyme has
drastically lower activity compared to the normal enzyme. Which of the following is the
most likely explanation for how the amino acid substitution has resulted in decreased
catalytic activity by the mutated enzyme? A. The substitution decreased the mass of the
enzyme so that the mutated enzyme binds more weakly to the substrate than the normal
enzyme does.
B. The substitution altered the secondary and tertiary structure of the enzyme so that
the mutated enzyme folds into a different shape compared to the normal enzyme.
C. The substitution caused many copies of the mutated enzyme to aggregate together
and compete for subs - Answer B. The substitution changed the secondary and tertiary
structure of the enzyme so that the mutated enzyme folds into a different shape than the
normal enzyme does.
An average bag of fertilizer contains large quantities of nitrogen, phosphorus, and
potassium and only trace amounts of magnesium and calcium. Which of the following
most accurately reflects the fertilizer component to the molecule it will be incorporated
by the organisms in the area?
A. Nitrogen will be incorporated into nucleic acids
B. Phosphorus will be incorporated into amino acids
C. Potassium will be incorporated into lipids
D. Magnesium will be incorporated into carbohydrates -Answer A. Nitrogen will be
incorporated into nucleic acids
Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen
synthase is one of the enzymes responsible for converting carbohydrate monomers into
polymers. Which of the following best describes the reactions of these enzymes?
A. Amylase acids in the removal of a water molecule to break covalent bonds whereas
glycogen synthase aids in the addition of a water molecule to form a covalent bonds.
, B. Amylase aids in the addition of a water molecule to break covalent bonds whereas
glycogen synthase aids in the removal of a water molecule to form covalent bonds.
C. Amylase catalyzes the addition of a water molecule to form covalent bonds whereas
glycogen synthase catalyzes
the removal of a water molecule to break covalent bonds
D. Amylase catalyzes the removal of a water molecule to form covalent bonds whereas
glycogen synthase catalyzes
the addition of a water molecule to break covalent bonds. - Answer B. Amylase
catalyzes the addition of a water molecule to break covalent bonds whereas glycogen
synthase catalyzes the removal of a water molecule to form covalent bonds.
A researcher measured the temperature at which two different samples of
double-stranded denature
(separate into single strands). Sample denatured at a much lower temperature
compared to sample.
Based on these data, the researcher claims that the in sample contains a higher
percentage of
guanine and cytosine than does the in sample.
Which of the following is the best evidence for the researcher's conclusion?
A. The bonds between guanine and cytosine are covalent bonds, which take more
energy to break than
do those between adenine and thymine.
B. Guanine-cytosine pairs denature at a higher temperature because they have more
hydrogen bonds between
them than adenine-thymine pairs do.
C.Adenine-thymine pairs require less energy to separate because adenine and thymine
are both singlering
bases.
D. Guanine-cytosine pairs require more energy to separate because one is a purine and
one is a pyrimidine. - Answer B. Guanine-cytosine pairs denature at a higher
temperature because they have more hydrogen bonds between
them than adenine-thymine pairs do.
