Evaluating Plastocyanin Properties
This solution analyzes the provided statements to identify the correct descriptions of plastocyanin.
Statement 1: Electron Transfer Role
Correct. Plastocyanin functions as a vital mobile electron carrier protein within the photosynthetic electron transport chain. It shuttles electrons between the cytochrome b6f complex and photosystem I.
Statement 2: Color in Oxidised Form
Correct. The copper ion within plastocyanin is a 'blue copper' center. In its oxidised state (Cu2+), it exhibits a distinct and intense blue color due to specific electronic transitions.
Statement 3: Metal Ion Geometry
Correct. The copper ion in plastocyanin is coordinated by two histidine nitrogen atoms and two cysteine sulfur atoms. This coordination results in a geometry that is best described as a distorted tetrahedral arrangement.
Statement 4: Metal Cluster Composition
Incorrect. Plastocyanin contains only a single copper atom. It does not feature metal clusters bridged by sulfide ions ($S^{2-}$), which are characteristic of iron-sulfur proteins, not copper-containing proteins like plastocyanin.
Conclusion
Based on the analysis, statements 1, 2, and 3 accurately describe properties of plastocyanin.
Important Questions from Bioinorganic Chemistry
Consider the following transformation reactions in the context of co - enzyme B12
A. 1, 2 - Carbon shift
B. Hydration of CO2
C. Benzene to phenol
D. Dimethyl sulfide to dimethyl sulfoxide
The correct statement(s) for co - enzyme B12 is / are
During the binding of O2 to myoglobin (consider 'heme' in xy-plane), the molecular orbital of O2 and atomic orbital of Fe involved in the formation of the σ-bond is
In the catalytic cycle of Cytochrome P450, the generation of [(porphyrin)+•FeIV(O)] from [(porphyrin)FeIII(OOH)] involves
Match List I with List II
List I
List II
Metalloprotein
Metal
A.
carboxypeptidase A
I.
Mn
B.
oxygen-evolving complex
II.
Fe
C.
hemerythrin
III.
Ni
D.
coenzyme F-430
IV.
Zn
Choose the correct answer from the options given below:
In solution, Vaska's complex is known to bind O2 reversibly. In the product, oxidation state of the metal ion center coordination geometry and mode of binding of O2, respectively are
