Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

DNA chains are extended on a template and from a primer with a(n) [____] in the

ID: 57151 • Letter: D

Question

DNA chains are extended on a template and from a primer with a(n) [____] in the 5 to 3

direction, allowing the chain to continue elongation when a mistake in polymerization has been removed

by [____]. In this case, the energy for the corrected nucleotide polymerization is provided by the

[____] deoxyribonucleotide triphosphate. If the DNA chain extension proceeded in a [____]

direction, the energy would have to be provided by the [____] deoxyribonucleotide triphosphate,

thereby blocking further repair and polymerization.

(1) RNA; DNA ligase; incoming; 5 to 3; polymerized

(2) free 5-OH; DNA polymerase; departing; 3 to 5; incoming

(3) overhang; uracil-DNA glycosylase; polymerized; 5 to 3; departing

(4) free RNA 3-OH; endonucleolytic proofreading; departing; 3 to 5; incoming

(5) free 3-OH; exonucleolytic proofreading; incoming; 3 to 5; polymerized

Explanation / Answer

(4) free RNA 3-OH; endonucleolytic proofreading; departing; 3 to 5; incoming

DNA chains are extended on a template and from a primer with a(n) [__Free RNA 3-OH__] in the 5 to 3 direction, allowing the chain to continue elongation when a mistake in polymerization has been removed by [__endonucleolytic proofreading__]. In this case, the energy for the corrected nucleotide polymerization is provided by the [__departing__] deoxyribonucleotide triphosphate. If the DNA chain extension proceeded in a [__ 3 to 5__] direction, the energy would have to be provided by the [__incoming__] deoxyribonucleotide triphosphate, thereby blocking further repair and polymerization.