Looking for a quick definition?
We’ve got loads of key subject terms in our subject glossaries. There are three ways of finding what you are looking for:
- First click on the letters of the alphabet to browse for terms.
- Select a subject from the drop-down menu above to filter the terms by Subject.
- Or lastly, type the term you are looking for into the search box.
Here are some examples of the kinds of definitions you’ll find on this page.
the movement of molecules across a membrane against the concentration gradient, from an area of...
a state in which the body has become dependent on a chemical substance in order to function.
a molecule that is converted to adenosine triphosphate (ATP) for energy storage.