7A AOL

LS7A AOL 1&2 Questions and Answers

T/F: Beta-carotene would be more likely to cross a pure lipid bilayer than Acetoacetate.

True

T/F: Guanine could form a hydrogen bond with water.

True

T/F: Guanine could form a hydrogen bond with an Acetoacetate molecule.

True

Which of the following words best describes beta-carotene?

A) Polar
B)Non polar
C)Amphiathic (has both polar and nonpolar regions)

Nonpolar

Psilocybin is hydrophobic.

False

Which curve represents the interaction between a Cl atom and an I atom?

Curve A
Curve B
Curve C

Curve A

Which atom pair forms a bond with the longest internuclear distance?

CI-F
Cl-l
N-N

C-I

Which atom pair forms the weakest bond?

CI-F
Cl-l
N-N

N-N

T/F: Breaking a bond between two N atoms would release 163 kJ/mol of energy.

False

Diagram B

Diagram C

Which molecule is represented by "Molecule A" in the graphs?

Lauric Acid
Stearic Acid
Hopene
More than one of these is possible

Stearic Acid

Which molecule is represented by "Molecule B" in the graphs?

Lauric Acid
Stearic Acid
Hopene
More than one of these is possible

Lauric Acid

You anticipate that as global climate change increases the temperature of the Earth over time, these bacteria will adapt to the increasing temperature by changing their membrane composition. Which molecule(s) do you expect to decrease in abundance over time as bacteria adapt?

Lauric Acid
Stearic Acid
Hopene
More than one of these is possible

Lauric Acid

Imagine that you were to repeat this experiment, but this time you wanted to compare Eicosapentaenoic acid, a polyunsaturated fatty acid with many double bonds, and Docasanoic acid, a saturated fatty acid with no double bonds. Both of these fatty acids are 20 carbons long. Under which conditions would you expect to see a decrease in Docasanoic acid?

Low Temeprature
High Temperature
Both
Neither

Low Temperature

T/F: Because the ∆G0 of this reaction is positive, this reaction will only occur in the cell if coupled to an exergonic reaction.

False

T/F: Succinate dehydrogenase will be used up during this reaction, so it must be replenished by the cell if the reaction is to continue occurring over time.

False

Which of the following statements accurately describes the effect of succinate dehydrogenase on this reaction?

A) Succinate dehydrogenase lowers the overall ∆G of this reaction, making it more favorable.

B) Succinate dehydrogenase provides the activation energy for this reaction to proceed.

C) Succinate dehydrogenase will make both the forward and reverse reactions occur at a faster rate.

D) Succinate dehydrogenase will speed up the forward reaction and slow down the reverse reaction

E) More than one of these is true.

F) None of these is true.

Succinate dehydrogenase will make both the forward and reverse reactions occur at a faster rate.

T/F: When this reaction is at equilibrium, the rate of the forward and reverse reactions will be equal to each other.

True

T/F: If standard enthalpy (∆H0) increases over the course of this reaction, then standard entropy (∆S0) could decrease.

True

What is the effect of calcium on pyruvate dehydrogenase activity?

Calcium is an activator
Calcium is an inhibitor
Not enough information

Calcium is an activator

T/F: The addition of calcium and NADH together decreases pyruvate dehydrogenase activity.

True

T/F: The addition of calcium to this reaction would result in less NADH production over the course of 100 minutes compared to the control reaction.

False

If you are doing an experiment where you want to produce the greatest amount of CO2 possible within 50 minutes, which of the following would you add to your control reaction?

NADH
Calcium
Both of these
Either of these
Neither of these

Calcium

Pyruvate is produced during glycolysis in the cytosol of a cell. For the citric acid cycle to occur, pyruvate needs to be transported into the mitochondrion. Based on what you know about the structure of pyruvate, would you expect that pyruvate would diffuse through the mitochondrial membrane, or would you expect a dedicated pyruvate membrane transport protein to exist?

Pyruvate should be able to diffuse through the mitochondrial membrane

A dedicated pyruvate membrane transport protein must exist.

A dedicated pyruvate membrane transport protein must exist.

Which free energy graph best represents the "Control + Calcium" experiment?

Graph A
Graph B
Graph C
Graph D
None of the above

Graph C

Which free energy graph best represents the "Uncatalyzed reaction" experiment?

Graph A
Graph B
Graph C
Graph D
None of the above

Graph D

Which free energy graph best represents the effect of increasing the concentration of substrate by 10x in the control experiment?

Graph A
Graph B
Graph C
Graph D
None of the above

Graph B

Based on the diagram and your knowledge of how membrane transport proteins work, which direction do you expect the Na+/Ca2+ to move its substrates through the cell membrane?

Both Na+ and Ca2+ into the cytosol

Both Na+ and Ca2+ outside of the cell

Na+ into the cytosol, and Ca2+ outside of the cell

Na+ outside of the cell, and Ca2+ into the cytosol

Na+ into the cytosol, and Ca2+ outside of the cell

T/F: Based on the information provided, the Ca2+ gated Ca2+ ion channel is a passive transport mechanism.

True

If the Na+/K+ pump stopped working, which of the following would you expect to observe?

Na+ concentration would increase outside of the cell.

Ca2+ concentration would increase inside the cytosol of the cell

The rate of Ca2+ movement through the voltage-gated Ca2+ ion channel (in response to a neuron signal) would decrease.

More than one of these would occur.

More than one

Based on the diagram and your knowledge of how membrane transport proteins work, which direction do you expect the Ca2+ pump to move Ca2+ through the organelle membrane?

From the cytosol into the sarcoplasmic reticulum

From the sarcoplasmic reticulum into the cytosol

It depends on the concentration of Ca2+ in the cytosol and the sarcoplasmic reticulum.

From the cytosol into the sarcoplasmic reticulum

Verapimil is a medication used to treat patients who are experiencing abnormally fast heartbeats. This drug works by preventing the voltage-gated Ca+ ion channel from opening in response to neuron signaling. When a patient is treated with Verapimil, what would be the effect on the movement of ions through the Ca2+ gated Ca2+ channel?

More Ca2+ ions would move through this channel.
Fewer Ca2+ ions would move through this channel
It depends

Fewer Ca2+ ions would move through this channel

T/F: The observations above suggest that the liquid in cup A could have been a very highly concentrated salt and sugar solution.

True

The observations above suggest that immediately after using the liquid in cup B to water your plant, the liquid in the soil of your potted plant was ________ compared to the cytosol of your plant cells.

Hypertonic
Hypotonic
Isotonic

Hypotonic

You have another plant that is a little bit different. You happen to know that its cell membranes are permeable to water and solutes. On Day 1, this plant looked similar to your original plant on Day 1. If you were to water this plant with the solution in cup A, this plant would be _________ compared to the plant shown above.

More shriveled
Less shriveled
Similarly shriveled

Less Shriveled

T/F: On day 3, there is no longer any water moving in or out of your plant’s cells.

False

T/F: Observation 4 is consistent with hypothesis 1.

True

T/F: Observation 1 is consistent with hypothesis 1 and inconsistent with hypothesis 2.

True

T/F: Observation 3 is inconsistent with hypothesis 1.

False

A) +16.0 kcal/mol
B) +14.0 kcal/mol
C)-1640 kcal/mol
D)-16.0 kcal/mol

-16.0 kcal/mol

In a cell, the ∆G of ATP hydrolysis is -7.3 kcal/mol. This indicates that:

A) The products of ATP hydrolysis are more stable than the reactants.
B) The products of ATP hydrolysis are less stable than the reactants.
C) The products of ATP hydrolysis and the reactants have approximately equal stability.

The products of ATP hydrolysis are more stable than the reactants.

T/F: Glycolysis is an example of a catabolic pathway. Therefore, over the course of glycolysis, entropy decreases.

False

T/F: The ∆G for the reaction that converts intermediate 4 to intermediate 5 during glycolysis will become more negative as the concentration of intermediate 5 increases in a cell.

False

T/F: The conversion of intermediate 7 to intermediate 8 is not coupled to ATP hydrolysis. Therefore, the ∆G of this reaction is most likely negative under cellular conditions.

True

Which organelle would you expect to see a lot of in human stomach cells that secrete a lot of enzymes?

Lysosome
Golgi Apparatus
Vacuole
Chloroplasts
Mitochondria

Golgi Apparatus

Which organelle would you expect to see a lot of in neurons that must continuously use the Na+/K+ pump to maintain an electrochemical gradient?

Lysosome
Golgi Apparatus
Vacuole
Chloroplasts
Mitochondria

Mitochondria

Which of the four molecules depicted above could not exist in nature?

Molecule A
Molecule B
Molecule C
Molecule D
All of these could exist

Molecule D

How many non-polar bonds exist in molecule B?

3

Which of molecules above could form Van der Waals interactions with another identical molecule?

Molecule A
Molecule B
Molecule C
Molecule D
All of these could exist

More than one of the above

T/F: The entropy of the protein decreases over the course of this reaction

True

T/F: As this reaction proceeds, a small amount of energy will be released as heat.

True

T/F: Foldase provides the energy required to make this reaction proceed in the direction shown by the arrow.

False

T/F: Because this process uses an enzyme, we know that this process is endergonic without the enzyme.

False

T/F: When foldase is present, the ∆G of this reaction becomes more negative.

False

Because the protein folding reaction proceeds in the presence of a specific enzyme and no other components, we can conclude that:

A) The reaction in the presence of the enzyme will not proceed any faster if the temperature is raised a few degrees

B) The reverse reaction (protein unfolding) would not proceed in the presence of the enzyme

C) The reaction would proceed in the absence of the enzyme but at a slower rate

D) The reaction would not proceed in the absence of the enzyme

The reaction would proceed in the absence of the enzyme but at a slower rate

T/F: The reaction depicted in free energy diagram C could be coupled to the reaction depicted in free energy diagram D to produce an exergonic reaction.

False

T/F: Because these diagrams depict changes in free energy over the course of a reaction, it is not possible to determine their relative reaction rates if no enzymes are involved.

False

T/F: The reaction depicted in free energy diagram C could represent ATP hydrolysis.

False

Athletes eat large meals containing carbohydrate and fat when they are in training but their body weight (mass) remains nearly constant. Which of the following statements correctly describes what happens to most of the mass consumed?

It is converted into adenosine triphosphate (ATP).

It is released as carbon dioxide and water.

It is converted to energy

It is released as CO2 and H2O

T/F: Mouse DNA must contain equal amounts of thymine and guanine.

False

T/F: Mouse DNA may contain a different number of purines and pyrimidines.

False

T/F: Mouse DNA must denature at the same temperature as human DNA.

False

Imagine you have discovered a new species of bacteria. To begin your investigation of this organism, you run an assay on the total nucleotide content of the bacterial DNA. The thymine content of DNA from the bacterial cells is 40%. You also run an assay on the total nucleotide content of E. coli, another species of bacterium. The thymine content of DNA from E. coli is 24%.

T/F: the DNA from your new bacterial species will denature at a lower temperature than the DNA from E. coli.

True

T/F: The sequence shown on your computer screen includes promoter regions for the S Protein gene and Gene X.

False

T/F: RNA polymerase will read the sequence for the S Protein gene from the 5’ end to the 3’ end of the template strand.

False

T/F: The primary structure of the proteins expressed from each of these genes will be the same.

False

T/F: The tertiary structure of S Protein and the protein expressed from Gene X will most likely be the same.

False

The amino acid sequence of Protein X begins Met-Gln-Leu. Which strand is the template strand for the Protein X gene?

Top strand
Bottom strand

The top strand shown in the diagram

How many total amino acids would you find in S Protein?

1253
1254
1255
1233
1243
A different number not shown above
Not possible to say without more information
1241

1,243

What is the second to last amino acid in S Protein?

Thr
Met
lle
Tyr
None

None of these

T/F: When transcribing Gene X, RNA polymerase will read the DNA sequence from the right side of your computer screen to the left side of your computer screen.

False

Which of the following changes to a codon would you expect to be most damaging to the resulting protein (all codons are written 5'->3')?

AGA->CGG
AAG->CGU
UCG->AGU
GAA->AAA

GAA->AAA

T/F: Region B could be a promoter sequence.

False

T/F: Region A does not appear to play a role in transcription.

True

T/F: Region C could contain a transcription factor binding site.

True

T/F: When region D is deleted, expression of GFP increases.

True

What is the highest level of protein structure shown in the 'RBCS subunit' image?

Primary
Secondary
Tertiary
Quartenary

Tertiary

What is the highest level of protein structure shown in the 'Dimer' image?

Primary
Secondary
Tertiary
Quartenary

Quarternary

T/F: Disrupting the secondary structure of RuBisCO would most likely affect its primary structure.

False

T/F: If heat were added to RuBisCO, the primary structure would be the first level of structure to be disrupted.

False

T/F: The tertiary structure of RuBisCO is formed primarily by covalent bonding between amino acids that are not necessarily adjacent to each other in the primary structure.

False

What level of protein structure is shown in the boxed green section of the full RuBisCO protein?

Primary
Secondary
Tertiary
Quartenary

Secondary

T/F: FMNox is an example of a reducing agent.

False

True

T/F: At the same time the total amount of NADH increases in a cell, the total amount of NAD+ in the cell will decrease.

True

Given that you know that the redox potential of AOX is +90, which molecule in the electron transport chain could AOX be accepting electrons from?

Cyt a1
FeS1
FMN
FeS2
More than one of these

More than one of these

If a plant cell begins producing AOX, the amount of Cyt cox will ______ compared to before AOX was present.
Increase
Stay the same
Decrease

Increase

T/F: When a plant is treated with DCMU, NADPH accumulates.

False

T/F: After a plant is treated with DCMU, light energy will still be absorbed by chlorophyll molecules in photosystem I.

True

T/F: When a plant is treated with DCMU, Pc accumulates in its reduced form

False

Treating a plant with DCMU will cause the plant's mass to ________ over time.
Increase
Decrease
Stay the same

Decrease

T/F: When a plant is treated with DCMU, G3P will accumulate in the chloroplast.

False

Adding a particular drug changes the redox potential of P700 from +420 to +310. Which of the following would you expect to observe in plant cells treated with this drug?

A) Phe would accumulate in its oxidized form.
B) ATP would continue to be produced in the chloroplast.
C) Pc would accumulate in its oxidized form.
D) Levels of 3-phosphoglycerate would decrease.
E) More than one of the above
F) None of the above

None of the above

Prometryn is an herbicide that acts as a photosystem II inhibitor (it prevents photosystem II from splitting water). If a plant were treated with prometryn, which of the following effects would you expect to observe?

G3P production would decrease

3-phosphoglycerate would accumulate in the chloroplast

NADPH would accumulate in the chloroplast

Pc would accumulate in its oxidized form

ATP production would decrease in the chloroplast

More than one of the above

None of the above

More than one of the above

Which of the following describes where the ribosome began translating this mRNA molecule?
At the AUG nearest to the 5' cap

At the beginning of exon 1

At the +1 transcription start site

At the 5' cap

At the promoter

At the AUG nearest to the 5' cap

T/F: The next amino acid added to the polypeptide will form a peptide bond with the Met amino acid.

False

What is the anticodon of the tRNA that brought histidine into the growing polypeptide chain?

3'-AUC-5'
3'-GAU-5'
3'-GUA-5'
3'-CAU-5'
None of the above

3'-GUA-5'

What amino acid will be attached to a tRNA with the anticodon sequence 3'-AUG-5'?

NONE OF THESE

In a certain mutant strain of bacteria, 10% of the tRNAs with the anticodon 5’-ACG-3’ are modified so that they have an anticodon of 5’-AGC-3’. These bacteria will synthesize:

Proteins in which serine is inserted at some positions normally occupied by tyrosine

Proteins in which tyrosine is inserted at some positions normally occupied by serine.

Proteins in which arginine is inserted at some positions normally occupied by alanine

Proteins in which alanine is inserted at positions normally occupied by arginine

Shorter proteins on average than the wild-type bacterium

Longer proteins on average than the wild-type bacterium

Proteins in which arginine is inserted at some positions normally occupied by alanine