During the posttranscriptional processing of pre-mRNA, a 5' cap is added to an mRNA in step-by-step manner. Which of the following reasons prevents the 5'capping process, involving methylation, from occurring on a DNA strand?
A) lack of an OH group on the 2' carbon of the deoxyribose
B) lack of an OH group on the 3' carbon of the deoxyribose
C) lack of a uracil nitrogenous base on the DNA strand
D) lack of GTP hydrolysis associated with DNA transcription
E) lack of a H on the 4' carbon of the deoxyribose

Question

Quizplus · Accepted Answer

The 5' capping process involves the addition of a methyl group to the 2' hydroxyl group of the ribose sugar in RNA. DNA lacks this 2' hydroxyl group because deoxyribose has a hydrogen atom instead, preventing the methylation step of capping.

During the Posttranscriptional Processing of Pre-MRNA, a 5' Cap Is