Question: the backbone of sugar molecules is
a. sulfur
b. oxygen
c. carbon
d. nitrogen

The “sides” of the ladder (or strands of DNA) are known as the sugar-phosphate backbone. This backbone consists of alternating phosphate and sugar groups, with the sugar molecule of one nucleotide linking to the phosphate group of the adjacent nucleotide. Connected to each sugar is a nitrogenous base.

Explanation:

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products