Question

Which one of the following is true of the pentoses found in nucleic acids?

• A. C-5 and C-1 of the two pentoses, are joined to phosphate groups by a Phosphodiester bond.
• B. C-5 of the pentose is joined to a phosphate group and C-1 to a nitrogenous base
• C. The pentoses are always in the -furanose forms.
• D. The straight-chain and ring forms undergo constant interconversion.

Answer 1

Answer: (B), (C)

The correct options are
B

C-5 of the pentose is joined to a phosphate group and C-1 to a nitrogenous base

C

The pentoses are always in the -furanose forms.

The pentoses found in nucleic acids are ribose and deoxyribose. The ribose and deoxyribose sugars bind to phosphate group at the C-5, and to the nitrogenous base at C-1.