Protein synthesis is vital for cell growth and metabolism. Describe transcription and translation Identify the similarities between transcription and translation Identify the differences between transcription and translation Describe structural changes that can occur to a protein after translation to make it function properly Solution Transcription: The ultimate function of a DNA strand is to produce proteins, for that; the DNA has to convert into RNA. In transcription, a part of the double-stranded DNA template helps for producing single-stranded RNA molecule. Only one strand of DNA serves as a template for transcription at any given time. This template strand names as the noncoding strand. The other strand refers as the coding strand because its sequence will be the identical as that of the novel RNA molecule. Transcripton helps in rises of many RNA molecusles like ribosomal RNA, non- coding RNA, transfer RNA and ribozymes. In most organisms, within the same chromosome, the strand of DNA that works as the template for one gene may be the nontemplate strand for another gene. It has following steps: Initiation: After choosing a strand, an enzyme RNA polymerase starts to make RNA by binding to the promoter sequence of DNA strand. This is called as initiation. In this step, the enzyme needs various transcriptonsal factors for recognizing and starting the process. The enzyme moves forward in the direction 3’ to5’ by skipping the promoter when all factors bind to the strand. Elongation: In this step, RNA polymerase codes RNA from the strand. Termination: the termination process needs to stop the unnecessary production of RNA. Translation: the process to produce proteins, translation is the step to make polypeptide chain(s) for protein. This step requires mRNA for template of coding sequences, a site for synthesis which is ribosome and tRNAs for every type of amino acid. The process includes following steps: Initiation: During initiation, ribosomal units cover the mRNA for creating a complete ribosome. Now, a tRNA which has anticode of AUG for the amino acid methionine, binds to ribosome. Elongation: it is the step of continuing the polypeotide synthesis. Termination: this step requires stopping the synthesis. The process is regulating by stop codons, when a stop codon appears the synthesis stops. Similarities between transcription and translation: Both require RNA Both processes have common procedure which follows initiation Elongation and termination. Difference between transcription and translation: Transcription Translation It synthesizes RNA It synthesizes polypeptide chain The RNA is as a product It requires mRNA as a template The template is DNA strand for transcription process RNA is as a template The process needs enzyme over DNA strand No enzyme is present over RNA Transcription factors requires for the synthesis No factors needed. Enzyme binds to promoter region of DNA tRNA binds to start codon of RNA The structural changes after transl.