# Recent questions and answers in Biochemistry

1
If the dissociation constant for solute-adsorbent binding is $K_D$, the retention time of the solute in a chromatography column increases with increasing $K_D$ decreases with increasing $K_D$ passes through minimum with increasing $K_D$ is independent of $K_D$
2
The product(s) resulting from the hydrolysis of maltose is/are a mixture of $\alpha$-D-Glucose and $\beta$-D-Glucose a mixture of D-Glucose and L-Glucose $\alpha$-D-Glucose only $\beta$-D-Glucose only
3
Amino acid residue which is most likely to be found in the interior of water-soluble globular proteins is Threonine Aspartic acid Valine Histidine
4
The reactions leading to the formation of amino acids from the TCA cycle intermediates are carboxylation isomerization transamination decarboxylation
5
The total number of fragments generated by the complete and sequential cleavage of the polypeptide given below by Trypsin followed by $CNBr$ is __________. $Phe-Trp-Met-Gly-Ala-Lys-Leu-Pro-Met-Asp-Gly-Arg-Cys-Ala-Gln$
6
Match the herbicides in $\text{Group I}$ with the target enzymes in $\text{Group II}$ ... $\text{P-4, Q-1, R-2, S-3}$ $\text{P-4, Q-3, R-2, S-1}$ $\text{P-3, Q-2, R-4, S-1}$
7
Match the entries in $\text{Group I}$ with the enzymes in $\text{Group II}$ ... $\text{P-4, Q-1, R-3, S-2}$ $\text{P-3, Q-1, R-4, S-2}$ $\text{P-3, Q-4, R-2, S-1}$
8
The catalytic efficiency for an enzyme is defined as $K_{cat}$ $\frac{V_{max}}{K_{cat}}$ $\frac{k_{cat}}{K_m}$ $\frac{K_{cat}}{V_{max}}$
9
Which one of the following is an $ABC$ transporter? multidrug resistance protein acetylcholine receptor bacteriorhodopsin $ATP$ synthase
10
Which one of the following aminoacids in proteins does $NOT$ undergo phosphorylation? Ser Thr Pro Tyr
11
Which one of the following modifications is common toboth protein and DNA? SUMOylation Nitrosylation Methylation Ubiquitination
12
In a chemostat, the feed flow rate and culture volume are $100$ ml/h and $1.0$ L, respectively. With glucose as substrate, the values of $\mu_{\text{max}}$ and $K_s$ are $0.2 \: h^{-1}$ and $1 \: g/L$, respectively. For a glucose concentration of $10 \: g/L$ in the feed, the effluent substrate concentration (in $g/L$) is _______
13
Yeast converts glucose to ethanol and carbon dioxide by glycolysis as per the following reaction: $C_6H_{12}O_6 \to 2C_2H_5OH + 2CO_2$Assuming complete conversion, the amount of ethanol produced (in $g$) from $200 \: g$ of glucose is (up to two decimal places) ____________
14
Consider a simple uni-substrate enzyme that follows Michaelis-Menten kinetics. When the enzyme catalyzed reaction was carried out in the presence of $10$ nM concentration of an inhibitor, there was no change in the maximal velocity. However. the slope of the Lineweaver-Burk plot increased $3$-fold. The dissociation constant for the enzyme-inhibitor complex (in nM) is ____________
A rod shaped bacterium has a length of $2 \: \mu m$, diameter of $1 \mu m$ and density the same as that of water. If proteins constitute $15 \%$ of the cell mass and the average protein has a mass of $50$ kDa, the number of proteins in the cell is __________ ($1$ Da $= 1.6 \times 10^{-24}$g)