16 FEBRUARY 2021 CURRENT AFFAIRS QUIZ

binding of oxygen to the heme

movement of the F-helix, which contains the proximal His

reorganization of protein-protein contacts between the individual subunits

movement of the proximal histidine towards the heme

1

None of these

2

not defined

decreasing Hb affinity for O2

increasing [H+]

increasing [H+] and decreasing Hb affinity for O2

increasing Hb affinity for O2

1.0 and 2.8

1.2 and 4.5

4.5 and 1.2

2.8 and 1.0

show a Hill coefficient (nH) of 0.0

both (b) and (c)

show a Hill coefficient (nH) of n

only be found in either the unliganded form or the fully liganded form

a linear Scatchard Plot

a sigmodial binding curve

both (b) and (c)

a hyperbolic binding curve

its binding pocket becomes too small to accommodate BPG

BPG binds to the R state with the same affinity as the T state

it is displaced from the heme by oxygen

it is displaced from the heme by movement of the proximal histidine

the amino acid residues lining the binding site

the absence of competing ligands

the presence of hydrating water molecules

the opposite chirality of the binding ligand

100-fold higher affinity for the last O2 bound than for the first

extensive protein conformational change

100-fold lower affinity for the last O2 bound than for the first

both (a) and (b)

to minimize oxygen delivery to the tissues

only in humans

for maintaining Fe in the Fe2+ state

to maximize oxygen delivery to the tissues