#Question id: 799
#SCPH05 I Biotechnology
The two cleavage reactions required to generate the miRNA from these primary transcripts are mediated by two distinct RNases. A characteristic of both these enzymes is that they recognize and cleave RNAs on the basis of the structure of their substrates rather than their specific sequence. Which of the following statement is INCORRECT regarding the cleavage reactions that produces a mature RNA?
#Question id: 14275
#SCPH05 I Biotechnology
Nicotiana tabacum cells are cultured
to high density for production of polysaccharide gum. The reactor used is a
stirred tank, containing initially 100 litres medium. The maximum specific
growth rate of the culture is 0.18 d-1 and the yield of biomass from
substrate is 0.5 g g-l. The concentration of growth-limiting
substrate in the medium is 3% (w/v). The reactor is inoculated with 1.5 g l-
1 cells and operated in batch until the substrate is virtually exhausted;
medium flow is then started at a rate of 4 l d-1. Fed-batch
operation occurs under quasi-steady-state conditions. Fed-batch operation
is carried out for 40 d. What is the final mass of cells in the reactor?
_____________________
#Question id: 4739
#SCPH06 I Botany
Inheritance of leaf variegation in the four-o’clock plant, Mirabilis jalapa. the leaves and shoots of one variety of four-o’clock were variegated, displaying a mixture of green and white splotches. If Flowers on the variegated branches gave rise to
#Question id: 20028
#SCPH01 Biochemistry
#Question id: 10342
#SCPH05 I Biotechnology
Nitrate reductase is an important enzyme for nitrate assimilation. Given below some regulation of nitrate reductase activity through phosphorylation and dephosphorylation.
a) Light, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby activates the enzyme
b) In Dark, and Mg2+ stimulate a protein kinase that phosphorylates the same serine residues, which then interact with a 14-3-3 inhibitor protein, and thereby inactivate nitrate reductase
c) In Light, and Mg2+ stimulate a protein kinase that phosphorylates the serine residues, and thereby activate nitrate reductase
d) In Dark, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby inactivates the enzyme
Which of the following statements about regulation of nitrate reductase is correct?