Biological pigments questions
1. Cyanidin is an anthocyanin found in berries and other fruits. The diagram below shows the structure of cyanidin in acidic solution and in alkaline solution. (a) Explain why cyanidin is coloured in both acidic and alkaline solution. (b) Explain why the colour of cyanidin changes from red in acidic solution (pH < 3) to blue when it is in alkaline solution (pH > 11). 2. Many biological pigments (e.g. haem and...