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?

TLS Online TPP Program

#Question id: 27068

#Unit 1. Molecules and their Interaction Relevant to Biology

Isoleucine and Threonine have two chiral carbons so exists in multiple RS configuration, choose the correct option regarding the given fig.

1. a is D-threonine is (2S, 3S) threonine

2. b is L-threonine is (2R,3S) threonine

3. a is L-threonine is (2S, 3R) threonine

4. b is D-threonine is (2R,3S) threonine

TLS Online TPP Program

#Question id: 27067

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose the correct statement regarding the stereochemistry of amino acid

1. 16 amino acid except (Thr, Ile, Cys, Gly) L Fischer projection is equal to S and D is equal to R configuration 

2. Thr, Ile is special case because of two chiral center exist in L – Ile/Thr – 2S,3R and D-Ile/Thr–2R,3S configuration  

3. Cys exiest in L- Cys – R & D- Cys – S configuration 

4. Gly is optically inactive 

TLS Online TPP Program

#Question id: 744

#Unit 1. Molecules and their Interaction Relevant to Biology

In a DNA molecule, deoxyribonucleotides are joined into a polymer by the covalent linkage of a phosphate group. The covalent link termed as:

TLS Online TPP Program

#Question id: 745

#Unit 1. Molecules and their Interaction Relevant to Biology

The structure of RNA differs from that of DNA, as RNA contains:

TLS Online TPP Program

#Question id: 746

#Unit 1. Molecules and their Interaction Relevant to Biology

Two separate chains of DNA are wound around each other, each following a helical (coiling) path, resulting in:

TLS Online TPP Program

#Question id: 747

#Unit 1. Molecules and their Interaction Relevant to Biology

In nucleic acids, the bases are covalently attached to the 1-position of a pentose sugar ring, to form a: