Scientific American Magazine

Presenting an issue on the fundamental particle of life. Anatomical and chemical views of the cell have now converged to show that it is not a droplet of protoplasm but a highly organized molecular factory

In the chloroplasts of plant cells the energy of sunlight is transformed into cells these fuels chemical fuels. In the mitochondria of animal are oxidized to run the cellular machinery

The inherited master plan of the cell is contained in the molecules of deoxyribonucleic acid. They direct the manufacture of protein enzymes, which in turn engineer all the chemical reactions of life

All cells arise by division. In the process of mitosis each cell is apportioned a complete set of hereditary instructions when the chromosomes replicate and are separated by the mitotic apparatus

The egg cell of a multicellular organism differentiates into all the specialized cells of the adult organism. It is now believed that this differentiation begins in the egg itself

The cells of many-celled organisms are marshaled and held together by specific physical and chemical factors. These factors are studied by dispersing the cells of a tissue and allowing them to recombine

It seems that some things passively flow through the cell membrane under various pressures, others are somehow actively pumped across the membrane and others are engulfed when the membrane folds inward

A paramecium moves by the beating of its cilia; an amoeba, by the streaming of its cytoplasm; a muscle, by its over-all contraction. All these processes appear to share an underlying molecular unity

The activities of cells in multicellular animals are co-ordinated by chemical messengers and nerve cells. During the past few years the character of the nerve impulse has been considerably clarified

In complex organisms certain cells are highly specialized to detect changes in the environment. The properties of such cells have been elucidated by studies of the visual receptors of the horseshoe crab