Final answer:
Hydrogen bonds play essential roles in biological molecules by shaping molecules, holding DNA strands together, and facilitating recognition processes.
Step-by-step explanation:
Hydrogen bonds play essential roles in biological molecules. They can form within a single large organic molecule and bend the molecule into a distinctive shape, which is important for its function. Hydrogen bonds also hold together the two nucleotide chains of a DNA molecule. Additionally, hydrogen bonds are involved in recognition processes such as DNA complementary base pairing and enzyme-substrate binding.