Download A plant has stunted growth and yellowing leaves because it is

PROCTOR VERSION
2.9 A: Molecular Basis of Exchange Quiz
1.
A plant has stunted growth and yellowing leaves because it is unable to synthesize key proteins
due to a nutrient deficiency. In which nutrient is the plant most likely deficient?
(A) Carbon, because it is an essential element in all organic molecules
Distractor Rationale:
This answer suggests the student may understand that carbon is present in many
biomolecules, but does not understand that nitrogen is an essential element in every
amino acid and that amino acids are used to synthesize proteins.
(B) Nitrogen, because it is an essential element of amino acids
Rationale:
This answer suggests the student understands that nitrogen is an essential element in
every amino acid and that amino acids are used to synthesize proteins.
(C) Oxygen, because it is an essential element in both nucleic acids and proteins
Distractor Rationale:
This answer suggests the student may understand that oxygen is present in nucleic acids
and proteins, but does not understand that amino acids are the building blocks of all
proteins and nitrogen is an essential element found in every amino acid.
(D) Phosphorus, because it is an essential element of nucleic acids
Distractor Rationale:
This answer suggests the student may understand that phosphorus is an essential element
in nucleic acids, but does not understand that nitrogen is an essential element in every
amino acid and that amino acids are used to synthesize proteins.
Aligned to: LO 2.9 CA 2.9: Represent & Model Matter Exchange
Page 1 of 6
PROCTOR VERSION
2.9 A: Molecular Basis of Exchange Quiz
2.
An unknown molecule is extracted from a cell. An analysis of the molecule’s atomic makeup is
shown in the table below.
Based on the data in the table, the unknown molecule should be classified as which type of
molecule?
(A) A carbohydrate
Distractor Rationale:
This answer suggests the student may understand that carbohydrates contain carbon,
oxygen, and hydrogen, but does not understand that carbohydrates do not usually contain
nitrogen and do not contain phosphorus.
(B) A protein
Distractor Rationale:
This answer suggests the student may understand that proteins contain carbon, oxygen,
nitrogen, and hydrogen, but does not understand that phosphorus is not found in proteins.
(C) A fatty acid
Distractor Rationale:
This answer suggests the student may understand that fatty acids contain carbon, oxygen,
and hydrogen, but does not understand that they do not contain nitrogen and phosphorus.
(D) A nucleic acid
Page 2 of 6
PROCTOR VERSION
2.9 A: Molecular Basis of Exchange Quiz
Rationale:
This answer suggests the student understands that nucleic acids are mostly made of
carbon, oxygen, nitrogen, and small amounts of phosphorus and hydrogen.
Aligned to: LO 2.9 CA 2.9: Represent & Model Matter Exchange
3.
The diagram below shows an endergonic reaction in which a dipeptide is formed from two amino
acids in a cell.
Which statement best explains this reaction?
(A) This is a hydrolysis reaction because a water molecule is produced when the amino acids
bond to form the dipeptide.
Distractor Rationale:
This answer suggests the student may understand that water is involved in a hydrolysis
reaction, but does not understand that this is a dehydration synthesis reaction because a
hydrogen atom is removed from one amino acid and a hydroxyl group is removed from the
other, and that the hydrogen atom and the hydroxyl group form a water molecule, which is
released to the environment.
(B) This is a dehydration synthesis reaction because a hydrogen atom is removed from one
amino acid and a hydroxyl group is removed from the other amino acid in order to form the
dipeptide.
Page 3 of 6
PROCTOR VERSION
2.9 A: Molecular Basis of Exchange Quiz
Rationale:
This answer suggests the student understands that this is a dehydration synthesis reaction
because a hydrogen atom is removed from one amino acid and a hydroxyl group is removed
from the other, and that the hydrogen and hydroxyl group form a water molecule, which is
released to the environment.
(C) This is a dehydration synthesis reaction because the hydroxyl group in the water molecule
donates an electron to one of the amino acids, which is used to form the dipeptide.
Distractor Rationale:
This answer suggests the student may understand that this is a dehydration synthesis
reaction, but does not understand that a hydrogen atom is removed from one amino acid
and a hydroxyl group is removed from the other, and that the hydrogen atom and the
hydroxyl group form a water molecule, which is released to the environment.
(D) This is a hydrolysis reaction because a water molecule is used to fuse two amino acids into
a dipeptide.
Distractor Rationale:
This answer suggests the student may understand that hydrolysis reactions involve water,
but does not understand that a hydrogen atom is removed from one amino acid and a
hydroxyl group is removed from the other, and that the hydrogen atom and the hydroxyl
group form a water molecule, which is released to the environment.
Aligned to: LO 2.9 CA 2.9: Represent & Model Matter Exchange
Page 4 of 6
PROCTOR VERSION
2.9 A: Molecular Basis of Exchange Quiz
4.
An experiment was done to test the effects of saliva on two carbohydrates: starch and maltose.
Each carbohydrate was mixed with water only or saliva only and then tested for the presence of
starch and maltose. The results are shown in the table below.
Which statement best explains the results observed in the experiment?
(A) Enzymes in the saliva digest the starch via a hydrolysis reaction to produce maltose.
Rationale:
This answer suggests the student understands that enzymes in the saliva digest the larger
starch molecule into the smaller maltose molecules.
(B) Enzymes in the saliva synthesize starch via dehydration synthesis from maltose molecules.
Distractor Rationale:
This answer suggests the student may understand that saliva changes starch into maltose,
but does not understand that maltose is not being synthesized in this experiment.
(C) Enzymes in the saliva produce maltose from starch molecules via biosynthesis.
Distractor Rationale:
This answer suggests the student may understand that maltose molecules and starch
molecules are involved in biosynthesis reactions, but does not understand that maltose is
produced from the digestion of starch.
(D) Enzymes in the saliva produce starch from maltose molecules via digestion.
Page 5 of 6
PROCTOR VERSION
2.9 A: Molecular Basis of Exchange Quiz
Distractor Rationale:
This answer suggests the student may understand that saliva is involved in digestion, but
does not understand that the production of starch is not from the digestion of maltose but
from biosynthesis of maltose.
Aligned to: LO 2.9 CA 2.9: Represent & Model Matter Exchange
Page 6 of 6