Question

4) What happens when the ribosomal complex encounters a stop codon? Explain which, if any, tRNAs or proteins are involved

5)If the following DNA strand was used as a template, what would the sequence of an RNA be?
5́ GTACCGTC 3́

6) How does acetylation of the chromatin affect the translation of genes contained within? In other words, does acetylation allow or inhibit transcription, and how?

Answer 1

4- Non-sense codon or stop codon doesn't code for amino acids. So there is no tRNA which recognizes the stop codon. When ribosomal complex encounters a stop codon, it waits for the right tRNA to come and recognize stop codon. Since there are not tRNA for stop codon, ribosome complex dissociates at that point, and translation stops

5- template strand is complementary to the coding strand. mRNA is the same as the coding strand, but in mRNA, Thymine is replaced by Uracil, and all the nucleotides remain the same

So the coding strand will be 3' CATGGCAG 5.'

and mRNA sequence will be 3' CAUGGCAG 5' or 5' GACGGUAC 3.'

6-Histone proteins are positively charged proteins due to high amount of basic amino. Due to its positive charge, histones can interact with the negatively charged DNA and make the complex inaccessible for transaction machinery. Acetylation occurs at the lysine residue of the histone proteins which results in decreasing the interaction of histone and DNA. As a result of it, chromatin gets relaxed and allow transcription machinery to bind the promoter and transcribe the gene.

Thus, does acetylation allow transcription.