膜

1. Origins, structure, and basic meaning

• Structure: 膜(まく) means a thin layer covering a surface or enclosing something.
• Basic usage: It can refer both to a thin film on milk and to the membrane surrounding a cell.

2. Common pitfalls and similar expressions

• Spelling compared with 幕
  • 幕(まく) means a curtain or screen, such as one used on a stage. Despite the shared reading, distinguish 膜 for a thin layer or biological membrane from the stage-related 幕.