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?

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#Question id: 33354

#Unit 1. Molecules and their Interaction Relevant to Biology

Oxygen binding to iron in heme can shown as

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#Question id: 33355

#Unit 1. Molecules and their Interaction Relevant to Biology

Which statement stands incorrect

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#Question id: 33356

#Unit 1. Molecules and their Interaction Relevant to Biology

Hemoglobin undergoes substantial changes in quaternary structure on oxygen binding: the a1b1 and a2b2 dimers rotate with respect to each other by

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#Question id: 33357

#Unit 1. Molecules and their Interaction Relevant to Biology

Protein A has a binding site for ligand X with a Kd of 10^-6 µM. Protein B has a binding site for ligand X with a Kd of 10^-9 µM. Which statement is incorrect?

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#Question id: 33358

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following situations would produce a Hill plot with n<  1.0?

(a) The protein has multiple subunits, each with a single ligand-binding site. Binding of ligand to one site decreases the binding affinity of other sites for the ligand.

(b) The protein is a single polypeptide with two ligand-binding sites, each having a different affinity for the ligand.

(c) The protein is a single polypeptide with a single ligand-binding site.

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#Question id: 33359

#Unit 1. Molecules and their Interaction Relevant to Biology

The protein calcineurin binds to the protein calmodulin with an association rate of 8.9 X10³ M^-1s^-1 and an overall dissociation constant, Kd, of 10 nM. The dissociation rate, kd