A student wants to find out if a food sample contains protein. Which test and positive result should the student use?
Add iodine solution; it turns blue-black.
Heat with Benedict's solution; it turns brick red.
Shake with ethanol; a white emulsion forms.
Add biuret reagent; it turns purple.
113 exam-style questions on OCR GCSE Biology 1.3 Respiration, covering 1.3.1 Cellular respiration supplies ATP, 1.3.2 Aerobic and anaerobic respiration, 1.3.3 Sugars and carbohydrates, 1.3.4 Amino acids and proteins, and 1.3.5 Fatty acids and lipids. Each one has a worked solution and a mark scheme showing where the marks go.