Question

What is wrong about protein synthesis?
A. Only one strand of DNA acts as a template for mRNA synthesis.
B. DNA polymerase mediates mRNA synthesis.
C. mRNA passes into cytoplasm and gets attached to 30S ribosomal subunit.
D. tRNAs bring amino acids one by one.
E. Translation is the process of protein synthesis.

Answer 1

Hint: Proteins are very large molecules composed of basic units called amino acids. In addition to containing carbon, hydrogen, and oxygen amino acids contain nitrogen. These molecules are large, complex molecules formed by one or more twisted and folded strands of amino acids. Certain important enzymes and organelles are involved that lead to the synthesis of proteins.

Complete answer:
The action by which mRNA codes for a particular protein is called translation. In the process of translation. The process of protein synthesis, i.e. elongation is carried out by the enzyme RNA polymerase. The ribosome translates the mRNA produced from DNA into a chain of specified/particular amino acids. This chain of amino acids generates protein. It is a process where the expense of ATP is needed and this energy is given by the charged tRNA. The whole equipment of translation is present in the ribosomes. The ribosomes consist of two subunits of various weights such as a bigger subunit and a smaller subunit. The larger subunit, in turn, consists of two molecules of tRNA that are placed close so that the peptide bond could be developed at the expense of sufficient energy. The mRNA enters the smaller subunit which is held by the molecules of tRNA of the complementary codon, that exists in the bigger subunit. Hence, two codons are carried by two molecules of tRNA, put down near to each other and a peptide bond is produced among them. When this process repeats, then a large number of amino acids are formed in a sequence which further leads to synthesization of amino acids chain.

Hence, the correct answer is option B.

Note: The central dogma describes how the DNA makes its own copies by DNA replication, then codes for the RNA by means of a transcription and RNA codes for the proteins by translation. For the design of a new generation, the genetic information stored in the DNA has to be delivered from one generation to another generation. The process starts with the replication of DNA and subsequently transcription and translation.