This puzzle worksheet reviews proteins, one of the four organic molecules. I gave this to my students after we went over notes and several activities about proteins and protein synthesis. For the puzzle, students first answer 15 questions. Then, they gather letters for each answer and unscramble them to find the answer to a riddle question. This worksheet will also work well as a homework assignment. This activity engages the students while they review material at the same time! This activity also lends itself to a competition. If you need 20 minutes to fill, this is perfect!