My MCQ

EXAM QUESTIONS

AMINO ACIDS

(1)    Two cysteine molecules will undergo a reduction reaction where the two ________   groups will lose their H via oxidation process to form a disulphide linkage.

(a)    Nitrogen hydryl

(b)   Sulphur hydryl

(c)    Sulphur oxide

(d)   Methyl

(e)   Carboxyl

(2)    Select the correct multiple answer using ONE of the keys A, B, C, D or E as follows:

A. 1, 2 and 3 are correct

B. 1 and 3 are correct

C. 2 and 4 are correct

D. only 4 is correct

E. all are correct

List amino acids with positively charged R groups:-

1. Lysine
2.  Arginine
3. Histidine
4. Aspartate

ENZYMES

(3)    Oxidoreductases are a class of enzymes which:-

(a)    Catalyse the transfer of C,N or P containing groups

(b)   Catalyse oxidation-reduction reactions

(c)    Catalyse cleavage of bonds by addition of water

(d)   Catalyse cleavage of C-C, C-s and certain C-N bonds

(e)   Catalyse racemization of optical or geometric isomers

(4)    Select the correct multiple answer using ONE of the keys A, B, C, D or E as follows:

A. 1, 2 and 3 are correct

B. 1 and 3 are correct

C. 2 and 4 are correct

D. only 4 is correct

E. all are correct

Enzymes-

(1)    Are biological catalysts

(2)    Speed up a chemical reaction

(3)    Provide an alternative pathway with lower activation energy

(4)    Provide an alternative pathway with higher activation energy