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?

#Question id: 23751

#Unit 1. Molecules and their Interaction Relevant to Biology

#Question id: 743

#Unit 1. Molecules and their Interaction Relevant to Biology

Glycophorin, an integral membrane protein, has a single transmembrane alpha helix. Which of the following idealized hydropathy plots most likely represents the transmembrane nature of glycophorin?

#Question id: 742

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following

#Question id: 741

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of following statements are INCORRECT about secondary structure of proteins

A. Long block of Glu residues segment of the chain will not form an alpha helix at pH 7.0 but it ll take helical confirmation below its pKR value

B. Long block of Lys residues segment of the chain will not form an alpha helix at pH 7.0 but it ll take helical confirmation above its pKR value

C. Long block of Ala residues segment of the chain will not form an alpha helix at pH 7.0 but it ll take helical confirmation below its pKR value

D. Histidine side chain remain uncharged over pH range 3-6

#Question id: 740

#Unit 1. Molecules and their Interaction Relevant to Biology

The conformation of the backbone of a polypeptide is described completely by the angle(s) of rotation about which bond(s)?

#Question id: 739

#Unit 1. Molecules and their Interaction Relevant to Biology

What is true about the rotation about bonds in a protein backbone?