Gene expression and flow of genetic information

The flow of the genetic information:
 

The flow of genetic information occurs through the process of transcription and translation.

Transcription is the transfer of the genetic information from DNA into RNA by the aid of an enzyme known as    

 polymerase.
DNA → RNA.

Translation is the transfer of the genetic information carried by the RNA into protein.
- RNA → Protein.
 

Worth noting that some viruses transfer the genetic information from DNA into RNA. This is the by the aid of an enzyme known as reverse transcriptase.

Transcription

In order to translate the genetic code into a protein product or a cell structure, the genetic code is first read and copied into another nucleic acid known as RNA. The process is known as transcription. RNA or ribonucleic acid is similar in structure to DNA except for two main differences; RNA nucleotides contain ribose sugars while DNA contains deoxyribose and RNA bases contain uracil instead of thymine present in DNA.

Translation:

The transformation of the information encoded in the nucleotides of mRNA into amino acid sequences that constitute a specific protein structure is known as the process of translation. Translation takes place in the cytoplasm when the m RNA is transferred from the nucleus into the cytoplasm.  In translation, ribosomes decode the messenger RNA (mRNA) genetic code to produce a specific polypeptide chain with the aid of another RNA known as transfer t-RNA.

Protein synthesis:

• Initiation: the recognition of the initiating codon of the mRNA and the transfer of a corresponding amino acid by specific tRNA to the small ribosome subunit.

• Elongation: the extension of the amino acid chain by the transfer of the subsequent amino acids to the proper ribosome site.

Termination: when the ribosome reaches the termination codon of the mRNA.