Chapter 12, Problem 1CONQ

Summary Introduction

To review:

The flow of information in the genes could be explained through the theory of central dogma.

Introduction:

In 1958, Francis Crick stated that central dogma is the process of transferring information into the protein, whichcannot be retrieved. The transfer from protein towards protein or protein to nucleic acid is impossible, whereas it is possible to transfer information from nucleic acid to nucleic acid or from nucleic acid to protein.

Explanation of Solution

In 1970, Crick again restated his statement, which stated that the detailed transfer of information cannot get transferred from protein and this is the main basis for central dogma. In simple words, the pathway for information in from DNA (deoxy ribonucleic acid) to RNA (ribonucleic acid) and then to protein. While according to James Watson, central dogma, the flow of information only takes place in two parts; one is from DNA to RNA and the other is from RNA to protein.

Replication- both, the somatic as well as the genetic DNA gets replicated in order to get a progeny of any cell. This is the primary step for DNA replication. Replisomes are the group of proteins that replicates information from the parental strand to the complementary daughter strand.

Transcription- the process of conversion of a particularDNA strand to mRNA(messenger RNA) with the help of RNA polymerase enzyme is called transcription. Formation of RNA strand that links the nucleotides is done by the RNA polymerase enzyme.

Translation- this is the second step of central dogma, wherein RNA gets converted to a long chain of amino acids called proteins done by tRNA (transfer RNA). The tRNA carries amino acid to the 3` ends, which gets along the protein chain.

The replication of RNA is called RNA replication, whereas the synthesis of DNA using an RNA template is termed as reverse transcription. By the use of E. coli (Escherichia coli), direct replication could be done from DNA to proteins in a test tube.

Conclusion

Therefore, it can be concluded that biopolymers have three major classes as DNA, RNA, and proteins and the conversion of DNA to RNA and RNA to proteins is termed as central dogma. In humans, there are 23 pairs of chromosomes and each cell has two copies. Firstly, unwinding and RNA synthesis takes place. Secondly, re-winding and release of pre-mRNA takes place, which gives DNA and pre-mRNA. Thirdly, tRNA molecules bind with the binding sites of the ribosomes of mRNA via hydrogen bonding. After the formation and breaking of several peptide bonds, the desired proteins are formed.