If there are a lot of branches, only small molecules can pass through.

They allow small molecules like those of traditional drugs to enter the brain.

It keeps all but the smallest molecules from getting through.

He said that scientists had considered the possibility of using light as a device for reading and writing information from the small molecules.

There are several theories about the origin of small molecules that could lead to life in an early Earth.

Around 1969, there was considerable interest in developing potential energy functions for small molecules.

A vitamin is a small molecule the body needs but cannot manufacture on its own.

Software taking advantage of this idea has been developed for both small molecules and proteins.

These also led to the discovery of several novel proteins and small molecules.

The presence of the functional group is generally easily established, at least in small molecules.