Which of the following important biochemical reactions in living systems is catalyzed by a ribozyme?

1. Repair of DNA

2. Electron transport chain

3. Formation of peptide bond

4. Organization of MTOC during cell division

A synthetic mRNA of repeating sequence 5'-CACACACACACACACAC... is used for a cell-free protein synthesizing system like the one used used by Nirenberg. If we assume that protein synthesis can begin without the need for an initiator codon, what product or products would you expect to occur after protein synthesis?

1. one protein, consisting of a single amino acid

2. three proteins, each consisting of a different, single amino acid

3. two proteins, each with an alternating sequence of two different amino acids

4. one protein, with an alternating sequence of two different amino acids

The enzyme that catalyzes the peptide bonding in prokaryotes is located in the:

1. Leader region of the mRNA

2. Central part of tRNA

3. Smaller subunit of the ribosome

4. Larger subunit of the ribosome

If there are 999 bases in an RNA that codes for a protein with 333 amino acids and the base at position 901 is deleted such that the length of teh RNA becomes 998 bases, how many codons will be altered?

(1) 1

(2) 11

(3) 33

(4) 333

Which of the following rRNAs act as structral RNA as well as ribozyme in bacteria ?

(1) 5 srRNA

(2) 18 srRNA

(3) 23 srRNA

 (4) 58 srRNA

Which one of the following pairs of codons are correctly matched with their function or the signal for the particular amino acid?

1. GUU, GCU – Alanine

2. UAG, UGA – Stop

3. AUG, ACG – Start/methionine

4. UUA, UCA – Leucine

The premature termination of polypeptide synthesis due to stop codon can be overcome via compensatory mutation in tRNA. This genetic phenomenon is called

(1) extragenic suppression

(2) intragenic suppression

(3) codon bias

(4) true reversion

Translocase is an enzyme required for

(1) DNA replication

(2) RNA synthesis

(3) initiation of protein synthesis

(4) protein synthesis chain elongation

Formation of peptide bond is

1. active process

2. passive process

3. both active and passive process

4. neither active nor passive process

Polypeptides are

1. dictated by DNA

2. represented by mRNA

3. Expresssion of t-RNA

4. Both 1 and 2