Multiple Choice QuestionsHow many tripeptides can be prepared by linking the amino acids glycine, alanine and phenyl alanine?
One
Three
Six
Twelve
C.
Six
Tripepndes are amino acids polymers in which three individual amino acid units, called residues, are linked together by amide bonds. In these, an amine group from one residue forms an amide bond with the carboxyl group of a second residue, the amino group of the second forms an amide bond with the carboxyl group of the third.
Therefore, glycine (NH2-CH2-COOH), alanine (CH3-CH(NH2)-COOH) and phenyl alanine (C6H5-CH2C(NH2)HCOOH) can be linked in six different ways.
A codon has a sequence of A, and specifies a particular B that is to be incorporated into a C. What are A, B and C?
A - 3 bases; B - amino acid; C - carbohydrate
A - 3 acids; B - carbohydrate; C - protein
A - 3 bases; B - protein; C - amino acid
A - 3 bases; B - amino acid; C - protein
The AT/GC ratio in human beings is (where A = adenine, T = thymine, G = Guanine, C = cytosine).
1
1.52
9.3
2
Which one of the following statements is not correct?
Except glycine all other naturally occurring α-amino acids are optically active.
α-amino acids have maximum solubility at their isoelectric point.
A tripeptide has two peptide bonds.
α-amino acids exist as Zwitter ions.
Which one of the following is true for an exothermic reaction A B, if Ef and Eb are the activation energies of forward and backward reactions respectively?
Ef > Eb
Ef = Eb
Ef = -Eb
Ef < Eb
The number of hydrogen bonds between guanine and cytosine and between adenine and thymine in DNA is
1, 2
3, 2
3, 1
2, 1
What are the substances which mimic the natural chemical messengers?
Antibiotics
Antagonists
Agonists
Receptors
Lactose is disaccharide of
α- D - glucose and α- D - fructose
β- D- glucose and β- D-galatose
α- D - glucose and β- D-ribose
α- D - glucose and β- D-galactose
Switch
