Understanding Biochemistry is a free, open-access, online resource produced by The Biochemical Society. It is a series of simple texts, published as part of the Essays in Biochemistry series, aimed at senior high-school and undergraduate students, and their teachers. They can be read online or downloaded as pdfs from the Portland Press web site:
The articles (available in English) are written and illustrated to make them easily understandable by students, providing up-to-date overviews of key concepts in biochemistry and molecular biosciences.
The following are available (as of February 2021) but other titles may be produced in the future: