The ends of a polynucleotide chain as 3 and 54 refer to
(B) Kinds of N-bases
present at these ends
(A) OH at 3rd carbon atom
and Pat 5 carbon
atom of sugars
respectively
(C) Free cabon positions
of N-base
(D) P and OH terminus
respectively
A??
Answers
Answer:
One nucleotide with another nucleotide. C. One nitrogenous base with pentose sugar. D ... Nucleotides join when the 3' carbon of the nitrogenous base bonds with the 5' phosphate
Answer:
A strand of DNA or RNA consists of nucleotides linked together by phosphodiester bonds.
A phosphodiester bond exists between the phosphate of one nucleotide and the sugar 3' carbon of the next nucleotide.
This forms a backbone of alternating sugar and phosphate molecules known as the sugar-phosphate backbone.
The two strands of DNA are also antiparallel (run in opposite directions) to one another. A strand of DNA can have direction 5'-3' or 3'- 5'.
One strand of the DNA molecule is 5'-3' and the other strand is 3'-5'. A DNA strand is assigned direction based on what is found at the end of the strands.
The end of the strand with a free phosphate is the 5' end because phosphate attaches to the 5' carbon of the sugar.
The end with a free OH group is the 3' end because the OH group is attached to the 3' carbon of the sugar.
So, the correct answer is option D.