Proteins and Enzymes: Structure and Function

Test your knowledge of enzymes in 16 questions: how they are named, what happens in the active site, and how temperature, pH and substrate levels change their speed. Real-life examples range from laundry detergents to diet soda labels and DNA copying. Every answer comes with a short explanation.

Can you name the one-letter code of all 20 standard amino acids? Type the letter used for each amino acid in protein sequences, then read why it got that letter and a key fact about it. Some codes are simply first letters, while others follow less obvious rules. Great practice for biochemistry, biology and molecular biology students.

Can you recognize all 20 standard amino acids from their structural formulas? Each picture shows one amino acid, and the answer options include molecules with similar side chains, so look closely. After every answer you will learn which feature of the side chain gives it away. Great practice for biochemistry, biology and molecular biology students.

Do you know the three-letter abbreviations of all 20 standard amino acids? Type the code used for each one, then find out where it comes from: most codes are simply the first three letters of the name, but a few break the rule. Each answer also explains the origin of the amino acid’s name. Useful practice for biochemistry, biology and molecular biology students.

Test what you know about photosynthesis: where a tree’s mass really comes from, how leaves capture light, how electrons travel through the photosystems, and how plants cope with heat and drought. 16 questions with explanations.

Go beyond the letters A to K. Test your knowledge of the chemical names of vitamins, where those names come from, which diseases a lack of them causes, which ones dissolve in fat or water, and the scientists who discovered them.