Protein Biosynthesis

Question 1

State the central dogma theory (crick’s law of molecular biology)

Answer 1

States that biological information flows from the nucleus (DNA) to the cytoplasm (RNA) and then to proteins (metabolic influence)

Question 2

What is the Genetic code ?

Answer 2

The genetic code is the systematic arrangement which places a nucleotide base in the gene of an organism thereby spelling out the amino acid such an arrangement represents

Question 3

The genetic code actually describes __

Answer 3

The mRNA (as DNA does not contain uracil)

Question 4

State crick’s wobble hypothesis

Answer 4

States that a single tRNA can recognize more than one codon, because U can base pair to G and A and G can base pair to U or C

Question 5

State the properties of the genetic code

Answer 5

1. It wobbles - the base pairs wobble are the third base of the codon
2. It is degenerate - more than one codon specifies a single amino acid
3. It is unambiguous - codon specifies only one amino acid
4. It is without punctuation
5. It is almost universal with rare exceptions
6. It is non overlapping - no one nucleotide base simultaneously belongs to two codons at the same time

Question 6

Cellular materials required for mRNA translation include ;

Answer 6

1) amino acids
2) mRNA template
3) ribosome
4) transfer RNAs
5) protein synthetic factors
6) energy sources

Question 7

What are the steps involved in protein biosynthesis ?

Answer 7

1) initiation
2) elongation
3) termination

Question 8

Explain initiation

Answer 8

Involves formation of a complex containing the initial methionyl-tRNA bound to the AUG “start” condone of the mRNA and to the “P” site of the ribosome