#Question id: 9171
#Unit 9. Diversity of Life Forms
Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species?
#Question id: 5056
#Unit 5. Developmental Biology
Cells of the responding tissue must have both a receptor protein for the inducing factor and the ability to respond to the signal. The ability to respond to a specific inductive signal is called as
#Question id: 10342
#Unit 6. System Physiology – Plant
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?
#Question id: 4300
#Unit 3. Fundamental Processes
Find correct order of cotranslational translocation in endoplasmic reticulum
A. Transfer of the nascent polypeptide–ribosome to the translocon leads to opening of this
translocation channel to admit the growing polypeptide adjacent to the signal sequence, which is transferred to a hydrophobic binding site next to the central pore. Both the SRP and SRP receptor, once dissociated from the translocon, hydrolyze their bound GTP and then are ready to initiate the insertion of another polypeptide chain.
B. As the polypeptide chain elongates, it passes through the translocon channel into the ER lumen, where the signal sequence is cleaved by signal peptidase and is rapidly degraded.
C. The SRP and the nascent polypeptide chain–ribosome complex bind to the SRP receptor in
the ER membrane. This interaction is strengthened by the binding of GTP to both the SRP and its receptor.
D. The ER signal sequence emerges from the ribosome; it is bound by a signal recognition particle (SRP).
#Question id: 19330
#Unit 12. Applied Biology