What components of a cell are most common?

The most common components of a cell are water and proteins. Water typically makes up around 70% to 90% of a cell's composition, playing a crucial role in maintaining cell structure, facilitating biochemical reactions, and serving as a solvent for various substances. This high water content is essential for maintaining homeostasis and allowing for the movement of materials within the cell.

Proteins are the second predominant component in cells, performing a myriad of functions critical for cellular processes. They are involved in structural support, enzymatic activities, transport mechanisms, and signal transduction, among other roles. Because proteins are essential for virtually every cellular function, their abundance in cells highlights their significance in maintaining life.

Considering the significance of both water and proteins in cellular functionality and structure, this choice reflects the fundamental aspects of cell biology accurately. The other components, while important, do not match the overall abundance and functional necessity of water and proteins in cellular life.