Download MIC 301 Introductory Microbiology

MMG 301 Introductory Microbiology
Refresher Quiz (Answers Below)
5’ end
|
deoxyribose--thymine
|
PO4|
deoxyribose--cytosine
|
PO4|
deoxyribose--cytosine
|
PO4|
deoxyribose--adenine
|
PO4|
deoxyribose--adenine
|
PO4|
deoxyribose--guanine
|
PO4|
deoxyribose--guanine
|
PO4|
deoxyribose--thymine
|
PO4|
deoxyribose--adenine
|
PO4|
deoxyribose--cytosine
|
PO4|
deoxyribose--cytosine
|
PO4|
deoxyribose--cytosine
|
3’ end
For questions 1-3, consider a portion of the noncoding
strand of DNA within a particular gene, whose structure is
represented by the diagram on the left (abbreviated to save
space):
1.a. Assuming that the gene in question encodes a protein,
and considering only the information content within this
stretch of the DNA alone (which is not within an intron),
what is the maximum number of amino acids that could be
encoded by this stretch of the DNA?
1.b. What is the minimum number?
2.a. Assuming that the maximum number of amino acids
possible are encoded by this portion of the DNA, and
considering Table 13.3 on page 268 of your text, what are
those amino acids?
2.b. What is their sequence within the corresponding portion
of the protein?
2.c. Which of those amino acids is closest to the carboxy terminal end of the protein?
2.d. Which one is closest to the amino-terminal end?
2.e. Of these amino acids alone, which was the first to be
incorporated into the protein during synthesis?
2.f. Which was the last?
2.g. Roughly how many amino acids are there in an "average"
protein?
3.a. What is the product of transcription of this portion of the
gene?
3.b. What is the product of translation?
4. Write balanced equations for the following 1/2 reactions:
a)
SO42- → S2-
b)
NO3- → N2
c)
CO2 → CH4
d)
NH3 → NO2-
5. Consider the following reaction:
H2S + NO3- → So + NO2- + H2O
a. Which compound(s) underwent an oxidation?
b. Which underwent a reduction?
c. Which compound was the oxidant?
d. Which was the reductant?
2
6. What is the hydrogen ion concentration in a dilute aqueous solution of sulfuric acid whose pH is 6.5?
7. Assume you start with 8 x 108 cells in 1.0 ml of growth medium (we will refer to this as the "original
population"):
a. If each individual cell divided once to yield 2 cells, how many total cells would there be now?
b. How many cells are in 0.2 ml of the original population?
c. How many cells are in 10% of the original population?
d. If 5 x 107 cells were removed from the original population, how many cells would be left?
e. If 0.7 ml of the original population was added to a bottle containing 13.3 ml of pure water and
mixed well, how many cells (on average) would now exist in each milliliter of liquid in the bottle?
f. What is the log10 of 8 x 108?
g. If the log10 of cells in 1.0 ml of water was 7.85733, how many cells per ml would there be?
8. Draw the structures of the following groups/bonds, which are part of various organic compounds: a) an
amino group; b) a carboxyl group; c) a methyl group; d) a hydroxyl group; e) a keto group; f) an aldehyde
group; g) an ether bond; h) an ester bond; i) a peptide bond.
Answers
1.a. Four amino acids.
1.b. Three amino acids.
2.a. - 2.f. Amino terminus---serine(first)-lysine-valine-proline(last)---carboxy terminus.
2.g. 350-400 amino acids.
3.a. A portion of messenger RNA having the following nucleotide sequence:
5’-U C C A A G G U A C C C-3’
4.
a.
b.
c.
d.
5.a. H2S;
-
2-
2-
SO4 + H+ + 8e → S + 4 H2O
2 NO3 + 12 H+ + 10e → N2 + 6 H2O
CO2 + 8 H+ + 8e → CH4 + 2 H2O
NH3 + 2 H2O → NO2- + 7 H+ + 6e
b. NO3
-
c. NO3
-6.5
-
d. H2S
-7
molar = 3.16 x 10 molar (assuming an activity coefficient
6. [H+] = 10
for H+ ≈ 1, which is the case for dilute solutions).
7.
a.
b.
c.
d.
e.
f.
g.
9
1.6 x 10 cells
8
1.6 x 10 cells
8 x 107 cells
8
7.5 x 10 cells
7
4.0 x 10 cells per ml
8.903
7
7.2 x 10 cells per ml
3
8. a & b: See text page 56
8c. R-CH3;
8.d R-OH