What is the make-up of a cell?

A cell is primarily composed of water, which makes up about 70-90% of its mass. It contains various organelles, such as the nucleus, mitochondria, and ribosomes, each serving specific functions. The cell's structure is supported by a cytoskeleton made of proteins, and it is enclosed by a plasma membrane that regulates the movement of substances in and out. Additionally, cells contain macromolecules like proteins, lipids, carbohydrates, and nucleic acids, which play crucial roles in cellular processes.