Different enzymes have specific active sites which can only catalyze one <span>substrate. Enzyme-substrate complexes are produced only when the substrate fits into the active site :)</span>
Answer:
The correct answer is option E. "nucleotides can only be added to an available 3'-OH group on the transcript terminus".
Explanation:
RNA synthesis is catalyzed by an enzyme called RNA polymerase. RNA polymerase always catalyze the synthesis of new RNA from 5' to 3' because nucleotides can only be added to an available 3'-OH group on the transcript terminus. This has been confirmed in labeling experiments with γ-32P substrates which establish the presence of a triphosphate moiety in transcripts with either pppG or pppA.
Mutation. this happens when a cell copies its DNA to divide. its more common than you may think, a "typo" occurs every 100, 000 or so nucleotides, thats about 120, 000 "typos" every time a cell divides.
The Five Kingdom classification
