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).

TLS Online TPP Program

#Question id: 27070

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements is correct regarding the stereochemistry of Thr, Ile 

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

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

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

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

TLS Online TPP Program

#Question id: 27069

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose the correct option regarding the stereochemistry of given compound 

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: