Solutions of three enzymes were prepared namely lipase, trypsin and amylase, in order to remove stains from a piece of cloth. Out of these three enzyme solutions, only lipase could completely remove the stain. This indicates that the stain was due to

Enzymes are biological catalysts characterized by high substrate specificity, meaning a specific enzyme only acts on a particular type of molecule [2]. Lipase is specifically responsible for breaking down fats, oils, and lipids into fatty acids and glycerol [1]. In contrast, trypsin (a protease) targets protein-based stains like blood or egg by breaking peptide bonds, while amylase targets starch-based stains like pasta or rice by converting complex carbohydrates into simple sugars. Since only the lipase solution was successful in completely removing the stain, it indicates that the stain's chemical composition consisted of lipids. If the stain had contained proteins or starch, the trypsin or amylase solutions would have shown some level of activity or removal [2]. Therefore, the stain was exclusively due to oil or grease.

Sources

1. [2] Science , class X (NCERT 2025 ed.) > Chapter 13: Our Environment > Activity 13.5 > p. 214
2. [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.3 > p. 86