Following statements are regarding to the desensitization mechanism of GPCR.

A. Several residues in the cytosolic domain of the β-adrenergic receptor are phosphorylated by the enzyme rhodopsin kinase.

B. β-Arrestin binds to specific phosphorylated tyrosine residues in the C-terminal segment of G protein–coupled receptors (GPCRs).

C. Clathrin and AP2, two other proteins bound by β-arrestin, promote endocytosis of the receptor.

D. β-Arrestin also functions in transducing signals from activated receptors by binding to and activating several cytosolic protein kinases like Src activates the MAP kinase pathway, leading to phosphorylation of key transcription factor.

Which of the following combination is incorrect?

#Question id: 382

#Unit 1. Molecules and their Interaction Relevant to Biology

The molar ratio of sodium acetate to acetic acid in a buffer solution with a pH OF 5.76 is 10:1. Assuming the total buffer concentration is 2.2 X 10^-2 mol/L, how many grams of sodium acetate (m.w. 82) and how many grams of acetic acid (m.w. 60) should be used in preparing a litre of the solution?

#Question id: 8935

#Unit 9. Diversity of Life Forms

#Question id: 2610

#Unit 2. Cellular Organization

Binding of RNA polymerase over promoter synthesizes

#Question id: 10464

#Unit 6. System Physiology – Plant

As with cryptochrome and phytochrome, the N-terminal photosensory region of the phototropins controls the activity of the C-terminal half of the protein, which contains a serine/threonine kinase domain. Following are some statements about photosensory region of the phototropins.

a) The activation of the C-terminal kinase domain then leads to receptor autophosphorylation on multiple serine residues that is required for all phototropin-mediated responses

b) In the dark, the N-terminal region, including the LOV domains, “cages” and inhibits the activity of the kinase domain

c) In the light, the N-terminal region, including the LOV domains, “cages” and inhibits the activity of the kinase domain

d) Absorption of blue photons by the LOV domains results in primary photochemical changes that lead to the uncaging of the kinase domain and its activation by the unfolding of the Jα-helix

Which one of the following combination of above statements is correct?

#Question id: 9254

#Unit 9. Diversity of Life Forms