BIOL 1013 - BIOLOGY OF THE CELL: PRACTICE EXAM II

1.Proteins are polymers made of units known as ______joined together by peptide bonds.

  1. amino acids
  2. nucleic acids
  3. phosphoric acids
  4. monosaccharides
  5. Choices C and D are both correct.

2.In a polypeptide chain, R groups that possess a net negative charge tend to belong to the ______family of amino acids (e.g., aspartic acid, glutamic acid).

  1. nonpolar
  2. polar
  3. basic
  4. acidic
  5. uncharged polar

3.The specific sequence of amino acids that make up a polypeptide chain from the N-terminus to the C-terminusend (e.g., Met-Asp-Leu-Tyr-Ser-Cys-Cys-Tyr) is referred to the ______structure of the protein.

A.primary

B.secondary

C.tertiary

D.quanternary

E.sequential

4.Of all the 20 naturally-occurring amino acids, which one is likely to possess an atom of sulfur as part of the side chain or R group?

  1. alanine
  2. glutamic acid
  3. glycine
  4. cysteine
  5. lysine

5.The  sheet structure can be illustrated as arrows in a ribbon drawing of a protein. By convention, the arrow points toward the C-terminus of the polypeptide chain. In the following figure, which one, upper (A) or lower (B), illustrates a parallel  sheet? The illustration below is meant for question #5.

A.The upper half of the drawing, (A), illustrates the parallel  sheet.

  1. The lower half of the drawing, (B), illustrates the parallel  sheet.
  2. Both drawings, (A) (B), illustrate the parallel  sheet.
  3. Neither drawing, (A) or (B), illustrate the parallel  sheet, but rather the antiparallel  sheet.
  4. Neither drawing, (A) or (B),illustrate the parallel  sheet, but rather the  helix.

6.Can a single polypeptide chain or protein possess both " helix and $ sheet folding patterns at the same time?

  1. Yes
  2. No
  3. Yes, but only if a prosthetic groupsare present to stabilize the entire structure.
  4. Yes, but only if disulfide bonds are present to stabilize the entire structure.
  5. Yes, but only if you are willing accept a universe where , ,, , , , , , , and  structures are also possible.

7.Two polypeptide chains bound together to form a functional protein would be a ______.

  1. monomer
  2. dimer
  3. trimer
  4. tetramer
  5. pentamer

8. Changes in conformation can allow a motor protein to move or “walk” along a filament or thread. The input of energy through cleavage of a high energy ______bond from ______allows for non-random motion of a motor protein. The input of energy is necessary if the protein is to move in one direction only instead of meandering back and forth at random. This results in directed movements in the cell.

The illustration below is meant for Question #8.

  1. phosphate; ATP or GTP (adenosine triphosphate or guanosine triphosphate )
  2. phosphate; AMP or GMP (adenosine monophosphate or guanosine monophosphate)
  3. phosphate; GDP(guanosine diphosphate)
  4. nitrate; GDN (guanosine dinitrate)
  5. Both choices B and Dare the best choices.

9.When Fred Griffith injected mice with a mixture of dead, pathogenic, encapsulated S (smooth) cells and living unencapsulated R (rough) cells of Streptococcus pneummoniae, he discovered that ______.

A.that the previously harmless strain had inherited the ability to produce capsules

B.a cure for pneumonia

C.the mice did not get sick from the pathogen

D.the enzyme called lysozyme

10.Rosalind Franklin’s used which technique to determine many of the physical characteristics of DNA?

A.light microscopy

B.DNA sequencing

C.chromatography

D.x-ray diffraction

11.In the pairing of nitrogenous bases in a DNA molecule, ______.

A.adenine is paired with cytosine

B.adenine is paired with guanine

C.cytosine is paired with thymine

D.guanine is paired with cytosine

E.thymine is paired with uracil

12.The Watson-Crick model of DNA structure suggested that the basis for the faithful copying of the genetic material is complementarity. This means that, if you know that the base sequence of one strand is3' AATTCG 5', the sequence of the other strand must be ______.

A.5' AATTCG 3'

B.5' TTGGAC 3'

C.5' TTAAGC 3'

D.5' TTAACG 3'

E.Do not have enough information to determine a viable response.

13.RNA differs from DNA in that it ______.

A. contains the 5-carbon sugar called ribose instead of deoxyribose

B. is single-stranded

C. contains uracil instead of thymine

D. is involved directly in protein synthesis

E. all of the above are correct

14.After three replications of a single DNA molecule, what percent of the resulting double helices contain one strand of the “original” DNA?

A.0 percent

B.25 percent

C.50 percent

D.75 percent

15. New molecules of DNA and RNA are assembled directly from nucleotides by means of enzymes called ______.

A. ligases

B. helicases

C. telomerases

D. polymerases

E. primases

16. At a replication fork, DNA helicase opens the double helix, while the DNA polymerase adds new nucleotides as it helps synthesize two new complementary strands to the two pre-existing DNA templates. DNA synthesis occurs ______along the leading strands and ______along the lagging strands.

A. continuously; continuously

B.discontinuously; discontinuously

C.continuously; discontinuously

D.discontinuously: continuously

E. discontinuously; discontinuously

17.Backstitching of DNA to combine Okazaki fragments into a continuous nucleotide strand that form during DNA replication is accomplished by an enzyme known as DNA ______.

A. ligase

B. helicase

C. telomerase

D. polymerase

E. primase

The illustrationbelow is meant for Questions #18

18. Damage to DNA that manifest itself in the conversion of the nitrogenous base cytosine to uracil of a particular nucleotide is called ______and results potentially, if not corrected by DNA polymerase or mismatch repair proteins, in a base ______.

A.depurination; substitution

B.depurination; deletion

C.deamination; substitution

D.deamination; deletion

E.dimerization; obliteration

19.The figure at the lower right is a diagrammatic representation of a molecule used in protein synthesis, also called ______.

The illustrationbelow is meant for Questions #19.

A. DNA

B. messenger RNA or mRNA

C. transfer RNA or tRNA

D. ribosomal RNA or rRNA

E. a protein

20.What is the maximum number of amino acids that a strand of mRNA can code for which contains thirty nucleotides? (Assume no start or stop codons!)

A. 1

B. 3

C. 10

D. 30

E. 21 (30 - 9)

21. If the anticodon on a tRNA molecule were CGA, the matching codon on mRNA would read ______, which would signal for the placement of ______in the growing polypeptide chain.

A.CGA; argininePARTIAL GENETIC CODE FOR QUESTION #21

B.GCU; alanineALANINE = GCA, GCC, GCG, GCU

C.GCA; alanineARGININE = AGA, AGG, CGA, CGC, CGG, CGU

D.UUU; phenylalanineMETHIONINE = AUG

E.AUG; methioninePHENYLALANINE = UUC, UUU