Encyclopædia Britannica, Inc. All cells need energy to function. Just as a car must burn fuel to get the energy it needs to run, the cell must burn fuel—for example, food—to get energy to carry …

Nov 28, 2025 · Cellular respiration, the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining …

Dec 1, 2025 · cell, in biology, the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed. A single cell is often a complete …

cell, In biology, the basic unit of which all living things are composed; the smallest structural unit of living matter that is able to function independently. A single cell can be a complete organism in …

Dec 1, 2025 · Cell - Structure, Organelles, Metabolism: Like the cell membrane, membranes of some organelles contain transport proteins, or permeases, that allow chemical communication …

Nov 25, 2025 · Each cell leads a double life: an independent one, pertaining to its own development alone; and another incidental, insofar as it has become an integral part of a plant.

Cell differentiation is a crucial part of development in multicellular organisms, since it results in cells with unique characteristics—such as muscle cells, neurons, or red blood cells —and …

Oct 27, 2025 · A plant cell is the basic unit of all plants. Plant cells, like animal cells, are eukaryotic, meaning they have a membrane-bound nucleus and organelles. Their …

A cell is a mass of cytoplasm that is bound externally by a cell membrane. Usually microscopic in size, cells are the smallest structural units of living matter and compose all living things.

5 days ago · The cell cycle is a four-stage process in which the cell increases in size, copies its DNA, prepares to divide, and divides. Learn more about the cell cycle and the proteins that …