19. Benedict's reagent is used to test for (a) proteins, (b) polysaccharides, (c) lipids, (c) nucleic acids, (e) reducing sugars.
20. Amino acids are the building blocks for (a) nucleic acids, (b) polysaccharides, (c) phosphates, (d) proteins, (e) lipids.
21. Coomassie blue can be used to stain (a) lipids, (b) carbohydrates, (c) proteins, (d) nucleic acids, (e) fatty acids.
22. Phospholipids are (a) hydrophobic, (b) hydrophilic, (c) amphipathic, (d) charged, (e) non-polar.
23. Biuret reagent (a) stains proteins violet, (b) stains lipids red, (c) stains carbohydrates orange, (d) is used to identify nucleic acids, (e) stains reducing sugars green.