Here's why:
* Selectively Permeable: The cell membrane is a thin, flexible barrier that acts as a gatekeeper, controlling what enters and exits the cell.
* Lipid Bilayer: It's primarily composed of a phospholipid bilayer, with a hydrophobic (water-fearing) interior and hydrophilic (water-loving) exterior.
* Protein Channels and Transporters: Embedded within the membrane are various proteins that facilitate the passage of specific substances:
* Channels: Act like tunnels, allowing small molecules like water, oxygen, and carbon dioxide to pass through.
* Transporters: Bind to larger molecules like glucose and amino acids, and help them move across the membrane.
In summary: The cell membrane's structure, with its selectively permeable nature and embedded proteins, is crucial for the passage of gases and nutrients, ensuring the cell's proper function and survival.
