Following statements are regarding to enzymatic processing of benzo(a)pyrene to a more potent mutagen and carcinogen.

A. Liver enzymes, particularly P-450 enzymes, modify benzo(a)pyrene in a series of reactions, producing 7,8-diol-9,10-epoxide, a highly potent mutagenic species that reacts with DNA primarily at the N2 atom of a guanine base.

B. The adduct, (+)-trans-anti-B(a)P-N2-dG, causes polymerase to insert an A rather than a C opposite the modified G base. Next time the DNA is replicated, a T will be inserted opposite the A, and the mutation will be complete.

C. Potent mutagen majorly causes conversion of guanine (G) to thymine (T) bases, a transition mutation.

D. When this potent mutagen applied to cultured bronchial epithelial cells, activated benzo(a)pyrene induces many mutations, including activating mutations at codons 175, 248, and 273 of the p53 gene.

Which of the following statements are correct?

TLS Online TPP Program

#Question id: 27072

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose the incorrect statement regarding the Van der Waals interactions & Hydrogen bonds

1. In Van der Waals interactions greater the area of contact the stronger the interaction.

2. In Van der Waals interactions greater the area of contact the weaker  the interaction.

3. Hydrogen bonds Relative strength is inversely proportional to the polarity More polar atoms form weak H bonds.

4. Hydrogen bonds Relative strength is directly proportional to the polarity More polar atoms form stronger H bonds.

TLS Online TPP Program

#Question id: 27071

#Unit 1. Molecules and their Interaction Relevant to Biology

Bond forces and their strength are given match them correctly 

TLS Online TPP Program

#Question id: 823

#Unit 1. Molecules and their Interaction Relevant to Biology

chaotropic agents such as guanidinium ion and urea, the efficiency of the chaotropic agent is measured in terms of-

TLS Online TPP Program

#Question id: 13001

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is incorrect 

a) antiparallel β sheets are frequently found and they are quite more stable because of more no. hydrogen bond presence and linear H bonding pattern.

b) antiparallel β sheets are frequently found and they are quite more stable because of more no. hydrogen bond presence and having distorted H bonding pattern.

c) parallel β sheets are relatively less stable and mostly found in core of protein.

d) parallel β sheets are relatively more stable and mostly found in core of protein.

TLS Online TPP Program

#Question id: 13000

#Unit 1. Molecules and their Interaction Relevant to Biology

Identify the correct statement regarding the structure

TLS Online TPP Program

#Question id: 12999

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline and glycine both disturb the symmetry of α-helix which of the following are true regarding to these two amino acids

a) proline changes the orientation of hetropolymeric α-helix hence proline can be placed only as 1st amino acid residue near to C-terminus 

b) proline changes the orientation of polymeric α-helix hence proline can be placed only as 1st amino acid residue near to N-terminus

c) glycine disrupts the heteropolymeric α-helix by changing the helicity.

d) homopolymer of proline and glycine can form stable helix.