Question

1. The most important aa in the production of AcCoA from pyruvate is
   1. His                  b. Lys              c. Tyr              d. Ser

2. Lactase, trehalase and sucrase can all be grouped as
   1. hydroxylases               c. transferases
   2. lyases                          d. oxidoreductases

3. The nucleophile involved in the conversion of acetaldehyde to ethanol is
   1. Zn²⁺                 b. H⁺                c. H^-                d. H^.

4. The number of electrons produced by one cycle of Krebs is
   1. 6                      b. 8                  c. 4                 d. 2

5. A phosphorylase
   1. is a kinase                   c. phosphorylates using phosphate
   2. is a hydroxylase          d. phosphorylates using GTP

6. The nitrogen present in purine bases is donated by    
   1. Glu                              c. Gly
   2. Gln                             d. Lys

Answer 1

Solution)- There are six questions from bioinorganic chemistry.In the first question, the most important aa in the production of AcCoA from pyruvate is Tyrosine.Histedine, Serine and Tyrosine, each has its own important roles.The roles in different stages of the synthesis are described ; In the Histidine Degradation we see the Conversion of histidine into glutamate.In the degradation of phenylalanine and tyrosine is the transamination of tyrosine to P-hydroxyphenylpyruvate. An another step of Phenylalanine and Tyrosine Degradation. The pathway for the conversion of phenylalanine into acetoacetate and fumarate.

In the second question Lactase, Tetrahalase and Sucrase are belongs to Hydroxylases Enzyme group.Option (a)Others have different functions All the given are commonoly grouped under 'Glucoside Hydolase' classification.In the third question, the nucleophile involved in the conversion of acetaldehyde to ethanol is H⁺.It is a reduction reaction. Here,Acetaldehyde is reduced by the addition of 2 electrons and 2 hydrogen ions supplied by NADH, which is reduced to NAD⁺.

Fourth question,Krebs or citric acid cycle is a series of reactions that takes place in acetyl CoA and produces carbon dioxide, NADH, FADH2, and ATP or GTP.The number od electrons produced in each kreb's cycle is 2.In each step there is a production of CO₂ and two electrons which reduces NAD⁺ to NADH. Fifth question is ,Phosphorylase is an enzyme and it catalyzes the addition of a Phosphate group.That is a Phosphorylase, phosphorylates using phosphate, option (c).Not other options.Kinase activates glycogen phosphorylase and etc.

In the sixth question we , the nitrogen present in purine bases is donated by Glutamine. option(a).Glutamine is the nitrogen donor for N-3 and N-9 of the purine nucleobases, adenine and guanine, and for the amino group of guanine.So, other options ae not the answer.