Scientific American Magazine

Introducing an issue about the new biology, which seeks to explain the molecular mechanisms underlying biological complexity. It has given rise to an industry, and to new ways of thinking about life

The genetic material's double helix, the fundamental molecule of life, is variable and also flexible. It interacts with regulatory proteins and other molecules to transfer its hereditary message

In all cells genetic information stored in DNA is converted into protein by RNA, which usually must be processed, even spliced, to serve its function. The first genes may have been spliced RNA

Proteins are the molecules encoded by genes. The proteins in turn give rise to structure and, by virtue of their selective binding to other molecules, make genes and all the other machinery of life

They spontaneously form a simple, two-dimensional liquid controlling what enters and leaves the cell. Some cells internalize and then recycle a membrane area equivalent to their entire surface in less than an hour

Proteins in the cytoplasm form a highly structured yet changeable matrix affecting cell shape, division and motion, and the transport of vesicles and organelles. It may also have a bearing on metabolism

The proteins that recognize foreign invaders are the most diverse proteins known. They are encoded by hundreds of scattered gene fragments, which can be combined in mlllions or blllions of ways

Chemical messengers mediate long-range hormonal communication and short-range communication between nerve cells. The two systems differ in directness, but some messenger molecules are common to both

The number of substances serving as signals in cells is remarkably small. Each such "second messenger" is a crucial guide for the cell, helping to determine how the cell responds to the organism's needs

How is the basic architecture of an embryo laid down? The discovery ofa short stretch of DNA called the homeobox apparently provides a crucial part of the answer in a remarkably wide range of organisms

The discovery that mutations accumulate at steady rates over time in the genes of all lineages of plants and animals has led to new insights into evolution at the molecular and the organismal levels