Which of the following metalloproteins does not have iron in the active site?

1. Hemoglobin

2. Hemerythrin

3. Hemocyanin

4. Cytochrome c

Which of the following is a heme iron protein?

1. Rubredoxin

2. Transferrin

3. Hemerythrin

4. Cytochrome c

The reduction of nitrogen to ammonia, carried out by the enzyme nitrogenase needs

1. 2e^- 

2. 4e^- 

3. 6e^- 

4. 8e^- 

Carboxypeptidase contains

1. Zn²⁺ and hydrolysis CO₂ 

2. Mg²⁺ and hydrolysis CO₂

3. Zn²⁺ and hydrolysis peptide bonds

4. Mg²⁺ and hydrolysis peptide bonds

Iron-sulphur clusters in biological systems are involved in

1. proton transfer

2. atom transfer

3. group-transfer

4. e^- transfer

Under physiological condition, oxygen is binding to deoxyhemoglobin the binding curve and its pH dependence, respectively are

1. Sigmoidal

2. hyperbolic

3. pH dependent

4. pH independent

Patients suffering from Wilson's disease have

1. Low level of Cu-Zn superoxide dismutase

2. High level of Cu-Zn superoxide dismutase

3. Low level of copper-storage protein, ceruloplasmin

4. High level of copper storage protein ceruloplasmin

The extent of $\mathrm{\pi }$ electron conjugation in macrocyclic rings (i) heme, (ii) coenzyme B₁₂ and (iii) chlorophyl follows the order

1. (i)>(iii)>(ii)

2. (i)>(ii)>(iii)

3. (iii)>(i)>(ii)

4. (ii)$\approx$(i)>(iii)

Oxidized form of enzyme catalase (structure A); prepared by the reaction of [Fe(P)]⁺ (P=porphyrin) with H₂O₂ has a green colour because of

1. Oxidation state of iron changed from Fe^III to Fe^IV.

2. Porphyrin ring is oxidized by one electron.

3. $\mathrm{\pi }-\mathrm{\pi }*$ transition appears in the visible region

4. Fe^IV is coordinated with anionic tyrosinate ligand in axial position.

The cooperative binding of O₂ in hemogoblin is due to

1. a decrease in size of iron followed by changes in the protein conformation

2. an increase in size of iron followed by changes in the protein conformation

3. a decrease in size of iron that is NOT accompanied by the protein conformational changes

4. an increase in size of iron that is NOT accompanied by the protein conformational changes