RNA is a highly dynamic biomolecule in that it
A) can fold and hydrogen bond with itself, DNA, proteins, or small molecules to adopt largely modified tertiary structures.
B) is less capable of forming stable H-bonds than DNA.
C) is often shorter than DNA.
D) is largely composed of a phosphate backbone.

Question

Quizplus · Accepted Answer

Unlike DNA, RNA is single-stranded, which allows it to fold and establish H-bonds with itself or other molecules to form complex tertiary structures that regulate gene expression and participate in many cellular processes. Moreover, RNA can recognize and interact with proteins, small molecules, and nucleic acids through specific binding sites that depend on its unique three-dimensional structure. So, option A is correct.

Answer: B, C, and D are incorrect.
 Option B is incorrect because RNA can form stable H-bonds with complementary nucleotides and protein side chains, although it may be more prone to structural fluctuations than DNA. Option C is also incorrect because RNA can be as long as some DNA molecules or even longer. Moreover, several functional RNA molecules are as short as a few nucleotides or even base pairs. Finally, option D is incorrect because although RNA has a backbone made of alternating sugar and phosphate units, it also contains nitrogenous bases that play key roles in its structure and function.

RNA Is a Highly Dynamic Biomolecule in That It