Question

Which of the following correctly describes the process of Translation?

I. tRNA anticodon bonds to mRNA codon

II. Ribosome bonds to mRNA strand

II. Ribosome reaches a STOP codon and detaches from the mRNA

IV. Each tRNA adds an Amino Acid to the chain as the Ribosome moves along the mRNA

V. Complimentary mRNA strand is made from DNA template

OA. V, I, IV, III B. II, IV, III, I, V C. II, I, IV, III D. V, II, I, IV, III

Answer 1

Answer) The correct option is C - II,I,IV,III

$\rightarrow$ I,II,III,IV represents the process of translation and V represents the process of transcription.

TRANSLATION

I. tRNA anticodon bonds to mRNA codon

II. Ribosome bonds to mRNA strand

II. Ribosome reaches a STOP codon and detaches from the mRNA

IV. Each tRNA adds an Amino Acid to the chain as the Ribosome moves along the mRNA

Translation is defined as the process of polymerization of amino acids to form a polypeptide. The mRNA consists of a sequence of bases which will define the order and sequence of amino acids. The peptide bond will join these amino acids, but for the formation of peptide bond some amount of energy is required. Therefore the first step in translation is to generate energy. For this, the amino acids will be activated in the presence of ATP and they are linked to their cognate tRNA( this process is commonly called as charging of tRNA or amino acylation of tRNA). These charged tRNA are brought together for the formation of peptide bond energetically. The rate of peptide bond formation is also increased by catalyst( ribosomes act as catalyst).

Ribosomes are the factory which will produce proteins.These ribosomes consists of structural RNAs and 80 different types of proteins. Ribosomes consist of two subunits; a large subunit and a small subunit. In the large subunit there are two sites, in these sites the subsequent amino acids will be bind for the formation of peptide bond. The function of small subunit is to encounter mRNA and to start the translation process of mRNA to protein.

There will be a translation unit in mRNA.It is the sequence of RNA that is flanked by the start codon(AUG) and a stop codon. mRNA also have sequences that are not translated and is called as untranslated regions(UTR). UTR can be seen before the start codon and after the start codon.But these UTR are necessary for the occurrence of efficient translation.

The process of translation starts with initiation, here the ribosome will bind to mRNA at the start codon(AUG). The tRNA will also get bind to mRNA and recognize the ribosome-mRNA bond. The next process will be the elongation of ribosome for the protein synthesis. The complexes composed of amino acids which are linked to tRNA will bind to the appropriate codon in mRNA by forming complementary base pairs with the tRNA anticodon.Ribosome will move from the codon to codon of mRNA.Each tRNA adds an amino acid to the chain as the ribosome moves along the mRNA in a specific order. These amino acid are translated into polypeptide sequences which are dictated by mRNA and represented by mRNA. At the last step, a release factor will be bonded to the stop codon and ribosomes will detach and terminating translation and finally releasing the completed polypeptide from the ribosome.

$\rightarrow$OPTION V IS INCORRECT BECAUSE IT IS THE PROCESS OF TRANSCRIPTION

V. Complimentary mRNA strand is made from DNA template

Transcription is the process of copying genetic information from one strand of DNA to RNA. Here a strand of DNA will act as a template for the synthesis of complimentary mRNA strand.