Bs-161 Final Exam (Fs16)

Front 1

Which argument best defends the charge of the solute seen here?

Back 1

The solute is negatively charged because all the water molecules are oriented with their hydrogen atoms facing the solute and in water molecules the hydrogen atoms have a partial positive charge.

Front 2

What type of molecule is represented in the diagram?

Back 2

A polymer made up of amino acids.

Front 3

What type of bond is indicated by the arrow in the diagram.

Back 3

It is a polar covalent bond.

Front 4

Below is a reaction showing the addition of a monomer to a polymer. What type of reaction is this?

Back 4

A dehydration.

Front 5

You have isolated DNA from a new species of bacteria and have determined that 20% of the bases are guanine (G). What percentage of the bases in the double-stranded DNA are adenine (A)?

Back 5

30%.

Front 6

What kinds of molecules pass through a cell membrane most easily?

Back 6

Small and hydrophobic.

Front 7

What does the statement "Phospholipids and most other membrane constituents (e.g., proteins) are amphipathic molecules" mean?

Back 7

They have both hydrophobic and hydrophilic regions.

Front 8

You perform an experiment in which the phosphate groups on the phospholipids on the outside of a cell are labeled with a fluorescent dye. A new cell is then created by fusing the labeled cell with a second cell in which the phospholipids are not labeled. Where would you expect to see the fluorescent dye after 15 minutes?

Back 8

Randomly distributed around the outside of the new cell.

Front 9

Imagine you find a plant with a mutation that makes it unable to produce polyunsaturated fatty acids. Compared to a normal plant that can produce polyunsaturated fatty acids, predict how this mutation might influence the plant's ability to survive as temperature changes.

Back 9

The plant with the mutation will not survive as well at lower temperatures.

Front 10

How did mitochondria and chloroplasts most likely arise?

Back 10

They arose from bacteria that were engulfed and not digested.

Front 11

Which is a major component of plant cell walls?

Back 11

Cellulose.

Front 12

In i-cell disease the enzyme in the golgi that normally adds the signal tag needed to target acid hydrolases to the lysosome no longer functions. Where are the acid hydrolases in cells with i-cell disease found?

Back 12

A.

Front 13

Based on this model of protein targeting, which statement accurately describes the synthesis and targeting of a protein that is part of the electron transport chain?

Back 13

The protein is synthesized on free ribosomes and requires an additional signal to reach its target.

Front 14

How is information transferred from inside the nucleus to the cytosol?

Back 14

RNA transcribed from the DNA is transported out of the nucleus.

Front 15

Which explanation accurately describes a reason why cells with a roughly spherical shape cannot exceed a certain size.

Back 15

As diameter increases, the volume increases more quickly than surface area. In large cells, there is not enough surface area for all the required membrane proteins like glucose transporters.

Front 16

Which of the following is the best explanation for the structure of mitochondria?

Back 16

Mitochondria require a large inner membrane surface area to house the integral membrane proteins of the electron transport chain.

Front 17

An exergonic reaction in the cell releases 73 kcal/mol. ADP phosphorylation to ATP requires 7.3 kcal/mol. Based on the second law of thermodynamics, which of these choices represents the maximum molecules of ADP that can be phosphorylated using the energy from one molecule going through this exergonic reaction?

Back 17

9.

Front 18

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ΔG of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ΔG for the new reaction?

Back 18

-20 kcal/mol.

Front 19

Which of the following does not represent a form of potential energy in a cell?

Back 19

The rotation of ATP synthase during oxidative phosphorylation.

Front 20

Cofactors, such as ADP, NAD+ and coA are synthesized through what process?

Back 20

Anabolism.

Front 21

Which carbon is most reduced? Assume the R groups are bonds to carbon atoms.

Back 21

A.

Front 22

pyruvate + NAD(+) + CoA --> acetyl-CoA + NADH + H(+) + CO2

What two parts of cellular respiration are connected by the process represented above?

Back 22

Glycolysis and the Krebs cycle.

Front 23

pyruvate + NAD(+) + CoA --> acetyl-CoA + NADH + H(+) + CO2

What is taking place during the process represented above as it proceeds from left to right?

Back 23

Carbon is oxidized and a coenzyme is reduced.

Front 24

What happens to the carbon atoms of glucose as they pass through glycolysis?

Back 24

One mole of glucose becomes two moles of pyruvate and some of the carbon atoms are oxidixed.

Front 25

The electron transport chain regenerates _____ which is used by the citric acid cycle to produce _____ .

Back 25

NAD(+), NADH.

Front 26

What happens in the final step of fermentation in your muscles?

Back 26

NAD(+) is regenerated by reducing pyruvate.

Front 27

Glycolysis is slowed when high concentrations of ATP cause ATP to bind to the third enzyme in the pathway at a site other than the active site of the enzyme and decreases the activity of the enzyme.

This is an example of what process?

Back 27

Feedback inhibition.

Front 28

Glycolysis is slowed when high concentrations of ATP cause ATP to bind to the third enzyme in the pathway at a site other than the active site of the enzyme and decreases the activity of the enzyme.

Which is the best explanation of why this regulation of glycolysis is important?

Back 28

ATP is a product of the pathway and when more ATP is being made than the cell is using the production of ATP should be reduced.

Front 29

Glycolysis is slowed when high concentrations of ATP cause ATP to bind to the third enzyme in the pathway at a site other than the active site of the enzyme and decreases the activity of the enzyme.

Which best explains how the binding of ATP to a site on the enzyme other than the active site can decrease the activity of the enzyme?

Back 29

Binding of the ATP causes subtle changes in the tertiary structure of the enzyme reducing the ability of the active site to bind the enzyme's substrate.

Front 30

The reactions depicted above are taking place _________.

Back 30

During the Calvin cycle.

Front 31

What is happening in the second reaction as it proceeds from left to right?

Back 31

Electrons from NADPH are used to reduce 1,3 BPG to produce G3P.

Front 32

Why are the leaves of plants green?

Back 32

Plant leaves are green because the energy of blue and red light has been converted into chemical energy.

Front 33

Which type of energy coupling happens in both cellular respiration and photosynthesis?

Back 33

The exergonic flow of protons is coupled to the endergonic synthesis of ATP.

Front 34

DNA must be condensed in order to fit in the nucleus of the cell. This is accomplished in part through specialized proteins. Which phenomenon best describes one way proteins condense DNA?

Back 34

Histones contain many amino acids with positive charges that interact with the negative charges on the DNA backbone causing the DNA to coil around the protein.

Front 35

Cytokinesis describes...

Back 35

Dividing a cell into two, normally after mitosis.

Front 36

Fluctuations in activity of Cdk/cyclins are important for regulating the cell cycle. Which of these lines on the graph above reflect the activity of the Cdk/cyclin complexes?

Back 36

A & C.

Front 37

Which line represents the concentration of S-cyclin during the cell cycle?

Back 37

D.

Front 38

Which of the following explanations best describes why diploid organisms have two alleles for a given gene?

Back 38

Homologous chromosome pairs contains DNA from an organism’s mother and father.

Front 39

In the Hershey-Chase experiment, what was used to selectively label protein?

Back 39

S(35), since sulfur is in some amino acids, but not in nucleotides.

Front 40

Which of the following enzymes is used to unwind the double stranded DNA making it single stranded?

Back 40

Helicase.

Front 41

Which structure represents a G/C base pair typically found in DNA?

Back 41

Base pair B.

Front 42

Scientists discover a Martian organism that contains a different genome than organisms on Earth. To discover which of the biomolecules contain this organism’s genetic information, they perform an experiment similar to Avery, McCarty, and MacLeod and discover that this organism uses protein as it’s genetic material. Extracts of this organism were treated with enzymes to destroy specific molecules and then used to transform Martian bacterial cells. Which extracts would still be able to alter the phenotype of the new cells?

A. Extract treated with DNase
B. Extract treated with RNase
C. Extract treated with protease
D. all of the above
E. A & B only

Back 42

A & B only.

Front 43

Which of the following statements correctly describe the difference between the synthesis of leading and lagging strands in the DNA replication process?

Back 43

The leading strand is synthesized continuously, whereas the lagging strand is synthesized in short fragments that are ultimately stitched together.

Front 44

Which of the following would you expect of a eukaryote lacking telomerase?

Back 44

A reduction in chromosome length in gametes.

Front 45

Which of the following statements best describes DNA replication?

Back 45

This is an anabolic process and requires energy, therefore it is coupled to hydrolysis of nucleotides.

Front 46

Replication in E.coli is initiated at ______ origin(s) of replication and proceeds in a _______________ and ________________ manner.

Back 46

One, semidiscontinuous, bidirectional.

Front 47

What role do spliceosomes play in eukaryotic transcription?

Back 47

They remove the introns from the mRNA during processing.

Front 48

A bacterial promoter sequence is changed so RNA polymerase is no longer able to bind. Which of the following statements is TRUE if the polymerase cannot bind?

Back 48

Initiation of transcription would not happen, since RNA polymerase is required for initiation.

Front 49

Which statement below is true for primase, DNA polymerase, and RNA polymerase?

Back 49

All three use DNA as a template to synthesize a nucleic acid.

Front 50

A protein contains 300 amino acids. What is the minimum number of nucleotides required to encode that many amino acids?

Back 50

900.

Front 51

Transcription bubbles often occur at a position called a “TATA box”. Why?

Back 51

These are A-T rich regions and this provides an easier spot to open the DNA double helix based on hydrogen bonding between bases.

Front 52

The diagram above is a model of the DNA template strand on which RNA polymerase is making RNA. In which region of the template would RNA polymerase add ribonucleotides next?

Back 52

D.

Front 53

Where in a plant cell would the majority of translation take place?

Back 53

Cytoplasm.

Front 54

During which stage of the cell cycle does DNA replication take place?

Back 54

S.

Front 55

The codon for glutamine is GAG. This codon only codes for glutamine and no other amino acids because the genetic code is _________.

Back 55

Unambiguous.

Front 56

Base-pairing is an important method for transferring biological information. Which of the following processes rely on base pairing?

A. Replication

B. Transcription

C. Translation

D. All of the above

E. A & B only

Back 56

D.

Front 57

Which of the following processes require energy input in the form of nucleotide hydrolysis?

A. Replication

B. Transcription
C. Translation

D. All of the above Incorrect

E. A & B only

Back 57

D.

Front 58

The Mars rover discovered a new organism and scientists have examined this new genetic material and found it has eight bases (instead of four, like ours). Assuming this organism uses a triplet codon like we do, how many unique codons could be accommodated by this genetic code?

Back 58

8^3 = 512.

Front 59

In the video regarding AquAdvantage salmon, the fish have been modified to contain a promoter from an eel like fish and a gene that encodes for a growth hormone from another species of salmon. Why is the AquAdvantage salmon able to produce a growth hormone protein from this gene despite the fact the gene comes from another variety of salmon?

Back 59

The genetic code in AquAdvantage salmon is the same as it is in all other species.