Class 22

      Today in class we discussed the process of protein synthesis. We learned about transcription, RNA processing, and translation. Protein synthesis comprises two major parts-transcription and translation. the process involves RNA, DNA, and a set of enzymes. All types of ribonucleic acid, namely mRNA, rRNA and tRNA are required for protein synthesis. Transcription is the first part in the process of protein synthesis. It takes place in the cell nucleus, where DNA is housed in the chromosomes. From the two parallel strands, one acts as a template to produce mRNA. As an initiation step of transcription, RNA polymerase binds itself to a particular site in one of the DNA strands that will act as a template. Following its attachment to DNA template strand, the polymerase enzyme synthesizes a mRNA polymer under the direction of the template DNA. The mRNA strand continues to elongate until the polymerase reaches a 'terminator region' in the DNA template.The newly transcribed mRNA is released by the polymerase enzyme, which is then migrated to the cytoplasm to complete protein synthesis process.The second primary part of the process is translation. Contrary to transcription that occurs in nucleus, translation takes place in the cytoplasm of the cell. This part is initiated as soon as the transcribed mRNA enters the cytoplasm. The ribosomes present in the cytoplasm immediately attach to the mRNA at a specific site, called the start codon. An amino acyl tRNA also binds at the mRNA strand

As the ribosome moves along the mRNA strand, the amino acyl tRNA brings amino acid one by one. This particular stage is called elongation. At the termination phase, the ribosome reads the last codon of the mRNA strand. With this, ends the translation part and the polypeptide chain is released. Precisely speaking, in translation, the ribosomes and tRNA attach to the mRNA, which read the coded information present in the strand. Accordingly protein synthesis of a specific amino acid sequence takes place.

Overall, protein synthesis process involves transcription of DNA to mRNA, which is then translated into protein. Thus, we have seen the process of protein synthesis requires proper coordination of RNA, DNA, enzymes and ribosomes. 

We then did an activity making snorks giving physical characteristics to them