Molecular Biology Exam test quiz
and answers graded A+
Compared to single covalent bonds, double covalent bonds are: - ANS✅✅Rigid with respect to
rotation
A covalent bond between two atoms is formed as a result of the: - ANS✅✅Sharing of Electrons
The chemical reactions in the cell occur primarily in a ____________________________
environment. - ANS✅✅Aqueous
The complex macromolecules of the cell are built from simpler molecular monomer subunits (e.g
amino acids, nucleotides) that are linked together through what type of chemical reaction? -
ANS✅✅Dehydration Synthesis
There are 90 naturally occurring elements on the earth, __________ of which compose >98% of the
mass of living organisms. - ANS✅✅CHNOPS
Which of the following bond types will are weakened in an aqueous environment? - ANS✅✅Ionic
Which of the functional groups outlined on the molecule below is a carboxylic acid? - ANS✅✅
Which of the functional groups outlined on the molecule below is a methyl? - ANS✅✅
Which of the molecules below is an amino acid? - ANS✅✅
Atoms with unfilled outer electron shells are especially stable and are therefore less reactive. -
ANS✅✅False.
Atoms that have their outer electron shells filled are the most stable and least reactive. Atoms with
unfilled outer shells are more reactive because they tend to share or transfer electrons to fill and
therefore stabilize the outer shell.
,DNA is synthesized by covalently linking nucleotides in a long chain. The DNA strand will become
part of a stable helix of two complementary strands. What is the principal force that holds the two
strands together? - ANS✅✅hydrogen bonds
Which of the following monomer building blocks is necessary to assemble selectively permeable
boundaries around and inside cells? - ANS✅✅fatty acids
A reaction with ΔG° = - 7.3 is directly coupled to a second reaction with ΔG° = +5.1, which is coupled
to a third reaction with ΔG° = +2.0. This is an energetically ________________ set of reactions? -
ANS✅✅Favorable
At first glance, it may seem that living systems are able to defy the second law of thermodynamics.
However, on closer examination, it becomes clear that although cells create organization from raw
materials in the environment, they also contribute to disorder in the environment by releasing -
ANS✅✅Heat
During respiration, energy is retrieved from the high-energy bonds found in certain organic
molecules. Which of the following, in addition to energy, are the ultimate products of respiration? -
ANS✅✅CO2, H2O. During respiration, energy is retrieved from the high-energy bonds found in
certain organic molecules.
Enzymes facilitate chemical reactions by: - ANS✅✅lowering the activation energy required for the
reaction to occur.
For the energy diagram for the reaction X→Y shown below. Which equation below provides the
correct calculation for the amount of free-energy change when X is converted to Y? - ANS✅✅c-a
For the reaction Y→X at standard conditions with [Y] = 1 M and [X] = 1 M, ΔG is initially a large
negative number. As the reaction proceeds, [Y] decreases and [X] increases until the system reaches
equilibrium. How do the values of ΔG and ΔG° change as the reaction equilibrates. - ANS✅✅ΔG
becomes less negative and ΔG° stays the same.
NADH and NADPH are activated carrier molecules that function in completely different metabolic
reactions. Both carry two additional __________ and one additional __________. This combination
can also be referred to as a hydride ion. - ANS✅✅Electrons, protons
, Oxidation is the process by which oxygen atoms are added to a target molecule. Generally, the atom
that is oxidized will experience which of the following with respect to the electrons in its outer shell?
- ANS✅✅Net loss
The best way to know if an organic molecule has been reduced is to see if there was an increase in
the number of __________ bonds. - ANS✅✅C-H
The energy used by the cell to generate specific biological molecules and highly ordered structures is
stored in the form of: - ANS✅✅Chemical bonds
The potential energy stored in high-energy bonds is commonly harnessed when the bonds are split
by the addition of __________ in a process called __________. - ANS✅✅water, Hydrolysis
The second law of thermodynamics states that the disorder in any system is always
______________. - ANS✅✅Total amount of energy in the universe remains constant.
When there is an excess of nutrients available in the human body, insulin is released to stimulate the
synthesis of glycogen from glucose. This is a specific example of a/an __________ process, a general
process in which larger molecules are made from smaller molecules. - ANS✅✅Anabolic
You have a reaction with a ΔG° = +3.5 kcal/mol. A product:substrate ratio greater than _______ is
required for this reaction to occur spontaneously. - ANS✅✅293.5
ΔG° indicates the change in the standard free energy as a reactant is converted to product. Given
what you know about these values, which reaction below is the most favorable? - ANS✅✅glucose
→ CO2 + H2O ΔG° = −686 kcal/mole, has to be negative to start reaction
Polypeptides are synthesized from amino acid building blocks. The condensation reaction between
the growing polypeptide chain and the next amino acid to be added involves the loss of: -
ANS✅✅a water molecule
The primary structure of a protein refers to: - ANS✅✅number and sequence of amino acids
The quaternary structure of a protein refers to: - ANS✅✅The association of multiple polypeptide
subunits to form a functional protein
and answers graded A+
Compared to single covalent bonds, double covalent bonds are: - ANS✅✅Rigid with respect to
rotation
A covalent bond between two atoms is formed as a result of the: - ANS✅✅Sharing of Electrons
The chemical reactions in the cell occur primarily in a ____________________________
environment. - ANS✅✅Aqueous
The complex macromolecules of the cell are built from simpler molecular monomer subunits (e.g
amino acids, nucleotides) that are linked together through what type of chemical reaction? -
ANS✅✅Dehydration Synthesis
There are 90 naturally occurring elements on the earth, __________ of which compose >98% of the
mass of living organisms. - ANS✅✅CHNOPS
Which of the following bond types will are weakened in an aqueous environment? - ANS✅✅Ionic
Which of the functional groups outlined on the molecule below is a carboxylic acid? - ANS✅✅
Which of the functional groups outlined on the molecule below is a methyl? - ANS✅✅
Which of the molecules below is an amino acid? - ANS✅✅
Atoms with unfilled outer electron shells are especially stable and are therefore less reactive. -
ANS✅✅False.
Atoms that have their outer electron shells filled are the most stable and least reactive. Atoms with
unfilled outer shells are more reactive because they tend to share or transfer electrons to fill and
therefore stabilize the outer shell.
,DNA is synthesized by covalently linking nucleotides in a long chain. The DNA strand will become
part of a stable helix of two complementary strands. What is the principal force that holds the two
strands together? - ANS✅✅hydrogen bonds
Which of the following monomer building blocks is necessary to assemble selectively permeable
boundaries around and inside cells? - ANS✅✅fatty acids
A reaction with ΔG° = - 7.3 is directly coupled to a second reaction with ΔG° = +5.1, which is coupled
to a third reaction with ΔG° = +2.0. This is an energetically ________________ set of reactions? -
ANS✅✅Favorable
At first glance, it may seem that living systems are able to defy the second law of thermodynamics.
However, on closer examination, it becomes clear that although cells create organization from raw
materials in the environment, they also contribute to disorder in the environment by releasing -
ANS✅✅Heat
During respiration, energy is retrieved from the high-energy bonds found in certain organic
molecules. Which of the following, in addition to energy, are the ultimate products of respiration? -
ANS✅✅CO2, H2O. During respiration, energy is retrieved from the high-energy bonds found in
certain organic molecules.
Enzymes facilitate chemical reactions by: - ANS✅✅lowering the activation energy required for the
reaction to occur.
For the energy diagram for the reaction X→Y shown below. Which equation below provides the
correct calculation for the amount of free-energy change when X is converted to Y? - ANS✅✅c-a
For the reaction Y→X at standard conditions with [Y] = 1 M and [X] = 1 M, ΔG is initially a large
negative number. As the reaction proceeds, [Y] decreases and [X] increases until the system reaches
equilibrium. How do the values of ΔG and ΔG° change as the reaction equilibrates. - ANS✅✅ΔG
becomes less negative and ΔG° stays the same.
NADH and NADPH are activated carrier molecules that function in completely different metabolic
reactions. Both carry two additional __________ and one additional __________. This combination
can also be referred to as a hydride ion. - ANS✅✅Electrons, protons
, Oxidation is the process by which oxygen atoms are added to a target molecule. Generally, the atom
that is oxidized will experience which of the following with respect to the electrons in its outer shell?
- ANS✅✅Net loss
The best way to know if an organic molecule has been reduced is to see if there was an increase in
the number of __________ bonds. - ANS✅✅C-H
The energy used by the cell to generate specific biological molecules and highly ordered structures is
stored in the form of: - ANS✅✅Chemical bonds
The potential energy stored in high-energy bonds is commonly harnessed when the bonds are split
by the addition of __________ in a process called __________. - ANS✅✅water, Hydrolysis
The second law of thermodynamics states that the disorder in any system is always
______________. - ANS✅✅Total amount of energy in the universe remains constant.
When there is an excess of nutrients available in the human body, insulin is released to stimulate the
synthesis of glycogen from glucose. This is a specific example of a/an __________ process, a general
process in which larger molecules are made from smaller molecules. - ANS✅✅Anabolic
You have a reaction with a ΔG° = +3.5 kcal/mol. A product:substrate ratio greater than _______ is
required for this reaction to occur spontaneously. - ANS✅✅293.5
ΔG° indicates the change in the standard free energy as a reactant is converted to product. Given
what you know about these values, which reaction below is the most favorable? - ANS✅✅glucose
→ CO2 + H2O ΔG° = −686 kcal/mole, has to be negative to start reaction
Polypeptides are synthesized from amino acid building blocks. The condensation reaction between
the growing polypeptide chain and the next amino acid to be added involves the loss of: -
ANS✅✅a water molecule
The primary structure of a protein refers to: - ANS✅✅number and sequence of amino acids
The quaternary structure of a protein refers to: - ANS✅✅The association of multiple polypeptide
subunits to form a functional protein
