Precision will be reduced, but yield will be increased

Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

A restriction enzyme cleaves a circular plasmid vector to produce fragments : 1kb, 0.3kb, 2kb, 1kb and 0.3kb. How many bands will be visible on agarose gel?

#Question id: 641

#Section 2: General Biology

Which of the following does NOT describe a mechanism that cells use to regulate enzyme activities?

A. Cells control enzyme activity by phosphorylation and dephosphorylation.

B. Cells control enzyme activity by the binding of small molecules.

C. Cells control the rates of diffusion of substrates to enzymes.

D. Cells control the rates of enzyme degradation.

E. Cells control the rates of enzyme synthesis.

F. Cells control the targeting of enzymes to specific organelles. 

#Question id: 642

#Section 2: General Biology

The graphs P, Q and R show the variation of rate constant (k) with temperature. The reactions represented by P, Q and R, respectively, are

#Question id: 644

#Section 2: General Biology

Enzyme X and Enzyme Y are both involved in monosaccharide metabolism. Enzyme X uses glucose as a substrate while Enzyme Y uses fructose as a substrate. At pH=7.0, Enzyme X has a Vmax of 10 μM/s while Enzyme Y has a Vmax of 20 μM/s. Both enzymes have a Km of 3.0 mM for their respective substrates. Which aspects of its reaction will be changed by Enzyme Y?

#Question id: 645

#Section 2: General Biology

Which of the following is the correct combination of marker enzymes used to identify different organelles during subcellular fractionation of eukaryotic tissue?

#Question id: 646

#Section 2: General Biology

Many biosynthetic pathways are regulated by feedback inhibition of enzymes. In a particular type of feedback inhibition, two endproducts individually do not inhibit an enzyme upstream in the pathway at all, but when both are present they inhibit the same enzyme significantly. What type of feedback inhibition do these inhibitors represent?

#Question id: 647

#Section 2: General Biology

For the hypothetical reversible reaction where S is converted to P, the rate constant for the forward reaction is 10⁵ s^-1 while that of the backward reaction is 10¹ s_-1. If the reaction is catalyzed by an enzyme, the rate constant for the forward reaction increases 100-fold. What will be the equilibrium constant of the enzyme catalyzed reaction?