231. The presence or absence of hydroxyl group on which carbon atom of sugar differentiates $$RNA$$ and $$DNA$$ ?
A
1st
B
2nd
C
3rd
D
4th
Answer :
2nd
232. The double strand helix structure of $$DNA$$ was proposed by
A
Har Gobind Khorana
B
Watson and Crick
C
A. R. Todd
D
G. W. Kenner
Answer :
Watson and Crick
233.
Within the list shown below, the correct pair of structures of alanine in $$pH$$ ranges 2-4 and 9-11 is
\[\begin{align}
& \left( \text{i} \right){{H}_{3}}{{N}^{+}}CH\left( C{{H}_{3}} \right)C{{O}_{2}}H \\
& \left( \text{ii} \right){{H}_{2}}NCH\left( C{{H}_{3}} \right)CO_{2}^{-} \\
& \left( \text{iii} \right){{H}_{3}}{{N}^{+}}CH\left( C{{H}_{3}} \right)CO_{2}^{-} \\
& \left( \text{iv} \right){{H}_{2}}NCH\left( C{{H}_{3}} \right)C{{O}_{2}}H \\
\end{align}\]
A
(i), (ii)
B
(i), (iii)
C
(ii), (iii)
D
(iii), (iv)
Answer :
(i), (ii)
234. Glucose - $$D$$ has a great tendency to be converted into cyclic isomer. Which two carbon atoms get joined through $$'O'$$ to form this hemiacetal ?
A
$${C_1}\,\,{\text{and}}\,\,{C_4}$$
B
$${C_1}\,\,{\text{and}}\,\,{C_5}$$
C
$${C_1}\,\,{\text{and}}\,\,{C_6}$$
D
$${C_2}\,\,{\text{and}}\,\,{C_6}$$
Answer :
$${C_1}\,\,{\text{and}}\,\,{C_5}$$
235.
Match the column I with column II and mark the appropriate choice.
| Column I | Column II | ||
|---|---|---|---|
| a. | Nucleoside | 1. | Sugar + base + phosphoric acid group |
| b. | Nucleotide | 2. | Cytosine + uracil |
| c. | $$DNA$$ | 3. | Sugar + base |
| d. | $$RNA$$ | 4. | Cytosine + thymine |
A
a - 3, b - 1, c - 4, d - 2
B
a - 1, b - 4, c - 3, d - 2
C
a - 2, b - 3, c - 1, d - 4
D
a - 4, b - 2, c - 1, d - 3
Answer :
a - 3, b - 1, c - 4, d - 2
236. Which of the following is not produced by human body?
A
Enzymes
B
Vitamins
C
Proteins
D
Nucleic acid
Answer :
Vitamins
237. The enantiomer of $$\alpha - D\left( + \right) - $$ glucose is
A
$$\beta - D - \left( + \right) - {\text{glucose}}$$
B
$$\alpha - D - \left( - \right) - {\text{glucose}}$$
C
$$\alpha - L - \left( - \right) - {\text{glucose}}$$
D
$$\beta - L - \left( - \right) - {\text{glucose}}$$
Answer :
$$\alpha - L - \left( - \right) - {\text{glucose}}$$
238.
During the process of digestion, the proteins present in food materials are hydrolysed to amino acids. The two enzymes involved in the process
\[\text{proteins}\xrightarrow{\text{enzyme}\,\left( A \right)}\] \[\text{polypeptides}\xrightarrow{\text{enzyme}\,\left( B \right)}\] \[\text{amino acids,}\] are respectively
A
invertase and zymase
B
amylase and maltase
C
diastase and lipase
D
pepsin and trypsin
Answer :
pepsin and trypsin
239. The hormone which controls the processes of burning of fats, proteins and carbohydrates to liberate energy in the body is
A
cortisone
B
adrenaline
C
thyroxine
D
insulin
Answer :
insulin
240. Which of the following treatment will convert starch directly into glucose?
A
Heating with dilute $${H_2}S{O_4}$$
B
Fermentation by diastase
C
Fermentation by zymase
D
Heating with dilute $$NaOH$$
Answer :
Heating with dilute $${H_2}S{O_4}$$