Question

1. describe the structure and function of the cell membrane:
2. how are proteins related to the cell membrane?
3. what is homeostasis and how does the cell membrane maintain homeostasis?

Explanation:

1. Structure: The cell membrane is a phospholipid bilayer with embedded proteins. Function: It controls what enters and exits the cell (selective permeability), protects the cell, and maintains cell shape.
2. Proteins in the cell membrane can be channel proteins (allow specific substances to pass through), carrier proteins (transport substances across the membrane), receptor proteins (receive signals), and structural proteins (maintain membrane integrity).
3. Homeostasis: The maintenance of a stable internal environment in an organism. The cell membrane maintains homeostasis by regulating the movement of substances (e.g., ions, nutrients, waste) in and out of the cell. For example, it can pump out excess ions or take in needed nutrients to keep the cell's internal conditions constant.

Answer:

1. Structure: Phospholipid bilayer with embedded proteins. Function: Selective permeability (controls substance entry/exit), protection, shape maintenance.
2. Proteins can be channel (substance passage), carrier (transport), receptor (signal reception), structural (integrity).
3. Homeostasis: Stable internal environment. Cell membrane regulates substance movement (e.g., ion/nutrient control) for constancy.