Which enzyme assay uses small oligosaccharides and 4-nitrophenyl-glycoside as substrates?

Which enzyme assay uses small oligosaccharides and 4-nitrophenyl-glycoside as substrates?

• A. Lipase
• B. Amylase
• C. Creatine kinase
• D. Cholinesterase

Answer: (B)

The main idea is using a glycosidase that acts on carbohydrate substrates together with a chromogenic surrogate. Amylase cleaves carbohydrate chains, so assays often use small oligosaccharides to resemble starch and a 4-nitrophenyl glycoside as the substrate. When the enzyme hydrolyzes the bond, 4-nitrophenol is released, producing a color change that can be measured spectrophotometrically. This setup provides a simple, quantitative readout of amylase activity. The other enzymes listed work on lipids, energy transfer compounds, or ester substrates, which require different substrate types and detection methods, so they don’t fit this substrate combination.

The main idea is using a glycosidase that acts on carbohydrate substrates together with a chromogenic surrogate. Amylase cleaves carbohydrate chains, so assays often use small oligosaccharides to resemble starch and a 4-nitrophenyl glycoside as the substrate. When the enzyme hydrolyzes the bond, 4-nitrophenol is released, producing a color change that can be measured spectrophotometrically. This setup provides a simple, quantitative readout of amylase activity. The other enzymes listed work on lipids, energy transfer compounds, or ester substrates, which require different substrate types and detection methods, so they don’t fit this substrate combination.