Question

from left to right, what are the three components of the nucleotide shown in this model?
a. 5 - carbon sugar, nitrogenous base, phosphate group
b. nucleic acid, 5 - carbon sugar, amino group
c. 5 - carbon sugar, nitrogenous base, carboxyl group
d. nitrogenous base, 5 - carbon sugar, phosphate group

Explanation:

A nucleotide is composed of three main parts: a nitrogenous base (which has a ring - like structure as shown on the left), a 5 - carbon sugar (the pentagon - shaped structure in the middle), and a phosphate group (the spherical structure on the right). Option A has the order wrong. Option B is incorrect because nucleic acid is a polymer of nucleotides, not a component of a single nucleotide, and amino groups are not part of nucleotide structure. Option C is wrong as carboxyl groups are not part of nucleotide structure.

Answer:

D. nitrogenous base, 5 - carbon sugar, phosphate group