Question

RUJUL POWIU Barn sel-se Question Completion Status: QUESTION 19 How many nucleotides are required for a glycosyltransferase to synthesize a disaccharide? Ca. 1%-2% of the total nucleotides b.2 c. 1 d.0 QUESTION 20 How does oxygen-binding affinity of hemoglobin change after the binding of 2,3-BPG? a. increases greatly b.decreases c. increases slightly d. does not change e. is strongly inhibited QUESTION 21 Which statement about a chymotrypsin substrate binding is FALSE? a Chymotrypsin binds its substrate with a deep hydrophobic pocket. The specificity of chymotrypsin depends almost entirely on which carboxylic acid is on the carboxyl-terminal side of the peptide bond to be cleaved. c. Few polar groups are present on the surface of the pocket. Cd. The pocket locks the substrate into an appropriate conformation for the active site to do its job. Oo. The specificity site of chymotrypsin is called the S1 pocket. 2 poin QUESTION 22 What is the magnitude of rotation of one ap dimer with respect to the other one upon oxygenation of hemoglobin? a. 90 degrees 63 degrees , Click Save and submit to save and submit. Click Save An Ansure to save all ans Save All Answers MacBook Pro

Answer 1

19) The answer is C) 1 nucleotide.

Glycosyl transferases are a group of enzymes that transfer the activated glycosyl groups which are attached to nucleotide diphosphate (NDP) for example GDP- Glucose donates glucose to the carbohydrate or non-carbohydrate acceptor.

NDP-sugar = acceptor sugar -------------> sugar-sugar (disacharide) + NDP

20) The answer is b) decreases

2,3 BPG is an allosteric inhobitor of Hb. It binds to the deoxy state of Hb and stabilises the low oxygen binding state in adult Hb. In foetal Hb it does not inhibit Hb.

21) The correct answer is

a) Chymotrypsin binds its substrate with a deep hydrobobic pocket.

This subrate binding site of chymotrypsin is a deep pocket covered  with hydrophobic amino acid (Phenyalanine)side chains.