: The structure and function of carbohydrates, lipids, proteins, and nucleic acids . 2. The Cell (Units 6–12)
As for the PDF download, I couldn't find a direct link to the 7th edition of "Biologia" by Campbell and Reece. However, I can suggest some possible sources: : The structure and function of carbohydrates, lipids,
: Exploring the chemical context of life, water, and the structure of macromolecules. and the structure of macromolecules.