ddNTP

Question 1

ddNTP, or dideoxynucleotide triphosphates

Answer 1

• are modified nucleotides used in Sanger sequencing.
  -They differ from their regular counterparts, dNTPs, by lacking a 3’ hydroxyl group on the sugar moiety.
• This characteristic makes ddNTPs chain-terminators, inhibiting the extension of DNA strands by DNA polymerase.

Question 2

moiety

Answer 2

In biology, a moiety refers to a specific portion of a molecule that has a recognizable structure and function. It’s essentially a named sub-unit within a larger molecule.

Question 3

Structure of ddNTPs:

Answer 3

They are composed of a sugar molecule (deoxyribose) with two phosphate groups and a nitrogenous base (adenine, guanine, cytosine, or thymine).

Question 4

Function of ddNTPs:

Answer 4

They act as chain-terminators in Sanger sequencing, preventing further DNA synthesis by blocking the formation of a phosphodiester bond between the last nucleotide and the growing chain.

Question 5

Applications of ddNTPs

Answer 5

They are used in conjunction with a modified Taq polymerase, which can only extend DNA chains in the presence of ddNTPs. This allows for the identification of specific DNA sequences by terminating the synthesis at the point of interest.