What are 2 functions of a cell membrane?

 

The cell membrane, also known as the plasma membrane, is a critical structure surrounding every living cell. It plays essential roles necessary for cell survival and proper function. Here are two main functions:

1. Acts as a Selective Barrier

• The cell membrane forms a semi-permeable barrier around the cell, which means it controls what enters and exits the cell.
• It helps keep essential cell components (like proteins and nucleic acids) inside and prevents unwanted substances from getting in, thus protecting the cell’s internal environment.
• This selectivity allows the cell to maintain a stable condition (homeostasis) regardless of changes outside the cell.

2. Regulates Transport of Materials

• The membrane governs the transport of nutrients into the cell and the removal of waste products.
• Specialized proteins in the membrane facilitate or actively transport substances across, ensuring that vital molecules (like glucose and ions) can enter, while harmful wastes are expelled.
• This function supports cellular activities and energy balance by allowing only certain molecules to cross through, either passively or with the use of energy.