question_answer 11)

Explain (in one or two lines) the function of the following: (a) Promoter (b) tRNA (c) Exons  

Answer:

(a) Promoter. The promoter flank structural gene in a transcription unit. The promoter is said to be located towards 5'-end (upstream) of the structural gene. It is the DNA sequence that provides binding site for RNA polymerase, and it is the presence of a promoter in a transcription unit that also defines the template and coding strands. (b) tRNA. It performs the adapter role that on one hand reads the code and on other hand would bind to specific amino acids. (c) Exons. The coding sequences or expressed sequences in eukaryotic genes are called as exons.