Final answer:
The bond between the sugar molecule and the nitrogenous base in a nucleotide is a glycosidic bond, specifically between the C1' carbon of the pentose sugar and the N1 or N9 of the nitrogenous base, formed through dehydration synthesis.
Step-by-step explanation:
Bond Between Sugar and Nitrogen Base in Nucleotides
In nucleotides, the bond that attaches the sugar molecule to the nitrogenous base is known as a glycosidic bond. This occurs specifically between the C1' carbon of the pentose sugar and the N1 of the pyrimidine base or N9 of the purine base. The formation of this bond is through a dehydration synthesis reaction, where a molecule of water is removed to link the sugar to the nitrogenous base. In addition, nucleotides are joined to one another in a nucleic acid chain via phosphodiester bonds, forming a sugar-phosphate backbone with the nitrogenous bases sticking out from this backbone.
In DNA, the four nitrogenous bases that may attach to this sugar-phosphate structure are adenine (A), guanine (G), cytosine (C), and thymine (T). Adenine and guanine are classified as purines with a double-ring structure, while cytosine and thymine are pyrimidines with a single-ring structure. These bases pair using hydrogen bonds to form stable structures; whereby adenine pairs with thymine, and cytosine pairs with guanine.