I have just started the AP Bio course. The questions in the exercise for the "Elements of life" section are all about identifying whether biological molecules are proteins, nucleic acids, carbohydrates or lipids depending on their chemical compositions. There's just one problem: Nothing in the videos and articles for this section gives you the information you need to solve these problems. Sal talks in general terms of about biological molecules and functional groups and of the types of elements involved, and gives a few examples. But at no point does he give any exact chemical definitions for what things like proteins or nucleic acids can or cannot contain. From the looks of the syllabus, this information is covered in lesson 4. So why are we being quizzed on it in lesson 2?

This is super disappointing and really indicates a basic lack of care and attention from whoever is preparing the exercises. I can only imagine how stupid it might make younger learners feel, watching the material then getting asked questions that they can't answer.