REPUBLIC OF CAMEROON

THE UNIVERSITY OF BAMENDA

Peace - work – Fatherland Box 39 Bambili, CAMEROON

Exercise 1: (3 marks) True or False

1) With the exception of essential amino acids, all amino acids can be synthesized de novo by the organism

2) Threonine unlike serine contains a thioester group that allow it to act as hydrogen donors in enzymes

3) Isoleucine is Essential for humans and as tend to be located inside of the protein molecule

4) The disulfide bond found in insulin is formed by 2 eystine molecules

5) Amino acids can display buffering property thanks to ionisable and non ionisible abilities

6) The Sanger sequencing method is an example of N-arylation reaction

Exercise 2: (16 marks)

1) The following peptides are subjected to normal electrophoretic analysis at pH 6.0

d2) Determine their pI

d3) Predict with justification their electrophoretic mobility under the present analytical conditions (3 marks)

Given: pKCOOH 2.1, pKCOOH 4.3, pKNH2 9.6, pKguanidium 12.5

Exercise 3: (11 marks)

The following graph represents curve of the absorption of nucleic acids as function of temperature.

1) Define nucleic acid, hypochronic effect, double helix, Tm (2 marks)

2) Justify the type of these nucleic acids (2 marks)

3) Analyse the graph (2 marks)

4) Determine the Tm of each nucleic acid (3 marks)