What term describes substances that have an affinity for water?

The term that describes substances with an affinity for water is "hydrophilic." Hydrophilic substances are polar or charged molecules that can easily interact with water due to their ability to form hydrogen bonds. This affinity allows them to dissolve in water, which is crucial for various biological processes, such as nutrient transport and biochemical reactions.

In contrast, hydrophobic substances are those that repel water and do not mix well with it, often lacking polar or charged regions. Amphipathic substances have both hydrophilic and hydrophobic regions, allowing them to interact with both types of environments but are not purely water-attracting. Nonpolar substances, similar to hydrophobic ones, lack the necessary polarity to interact favorably with water, further highlighting the significance of the hydrophilic nature of certain molecules in biological systems.