What does hydrophobic mean?

Hydrophobic refers to a substance's lack of affinity for water, meaning it tends to repel or avoid water. This characteristic is crucial in various scientific contexts, particularly in biology and chemistry, where understanding the interaction between molecules and water can determine solubility, permeability, and the overall behavior of substances in aqueous environments.

When a substance is hydrophobic, it will not dissolve or mix well with water, often resulting in separation if combined. This property is especially significant in cellular biology, where the hydrophobic nature of lipid molecules leads to the formation of cell membranes. These membranes act as barriers that separate the internal environment of the cell from the external, utilizing the hydrophobic interactions of lipids to maintain structural integrity.

In contrast, substances that absorb water and retain moisture indicate a hydrophilic nature, which is not applicable to hydrophobic materials. Similarly, the ability to mix readily with water or dissolve is characteristic of hydrophilic substances, not hydrophobic ones. While filtering out impurities from liquids involves different physical processes, it doesn't pertain to the definition of hydrophobicity. Thus, the definition of hydrophobic aligns perfectly with the concept of having an aversion to water.