Coenzyme B12 Metal Ion Binding Group Explained
Coenzyme $B_{12}$, also known as cobalamin, contains a central cobalt (Co) ion at its core.
In its biologically active forms, the cobalt ion forms a direct, covalent bond with an organic ligand. This type of bond is known as an organometallic bond.
A key coenzyme form of vitamin $B_{12}$ is adenosylcobalamin. In this specific structure, the cobalt ion is directly attached to the 5'-deoxyadenosyl moiety.
Thus, the group bound to the metal ion in coenzyme $B_{12}$ is the adenosyl group.
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
