An enzyme that repairs thymine dimers in visible light in E. coli

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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

TLS Online TPP Program

#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?

TLS Online TPP Program

#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

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#Question id: 33360

#Unit 1. Molecules and their Interaction Relevant to Biology

a. HbS (sickle-cell Hb): substitutes a Val for a Glu on the surface

b. Hb Cowtown: eliminates an ion pair involved in T-state stabilization

c. Hb Memphis: substitutes one uncharged polar residue for another of similar size on the surface

d. Hb Bibba: substitutes a Pro for a Leu involved in an α helix

Which Hb variant least likely to cause pathological symptoms

TLS Online TPP Program

#Question id: 33361

#Unit 1. Molecules and their Interaction Relevant to Biology

a. Hb Cowtown: eliminates an ion pair involved in T-state stabilization

b. Hb Milwaukee: substitutes a Glu for a Val

c. Hb Providence: substitutes an Asn for a Lys that normally projects into the central cavity of the tetramer

d. Hb Philly: substitutes a Phe for a Tyr,

Which Hb variant will not bind to BPG