Question

1. Which of the following amino acid residues in a protein would most likely be a target of a heavy metal such as Pb2+?

a) Glycine

b) Histidine

c) Methionine

d) Phenylalanine

2. Which of the following statements is true?
a)The percent saturation of hemoglobin with O₂increases as the pH decreases.Which of the following statements is true?

b)Infants are less able to reduce methemoglobin than are adults.

c)Carbon monoxide inhibits the oxidative phosphorylation process.

d)Disruption of the quaternary structure of proteins involves breaking peptide bonds.

e)Cyanide competes with oxygen for binding to hemoglobin.

Answer 1

1) for metal binding the amino acid may have

a) sulphur

b) carboxylic acid group in side chain

c) ring nitrogen

so the option will be Histidine as it contains ring nitrogen

2)

a) false: pH increase increases the affinity for O2

b) False : Infants are more able to reduce methemoglobin than are adults.

c) True: Carbon monoxide inhibits oxidative phosphorylation process by inhibiting electron transport chain by competing with oxygen to bind with cyctochrome complex

d) false: in quaternary structure disruption protein sub units are disturbed

e) false: it binds with the cytochrome of electron transport system not the haemoglobin