Question

What does it mean for a membrane to be selectively permeable?Select two specific components of the cell membrane and explain how each affects the permeability of the cell membrane. Meaning, what specific materials are regulated by the given component and how.Why is it important for a cell to regulate what molecules are able to pass into or out of the cell?

Answer 1

Answer:

Selective transport enables the substances to move rapidly through the cell membrane (for instance, H2O, O2 and CO2), while other substances pass through the cell membrane more slowly. Moreover, there are also compounds that can't pass through this barrier.

Explanation:

The selective transport of the substances across the cell membrane enables the cell to maintain the homeostasis of the system by maintaining the ionic equilibrium on both sides of the cell membrane. Moreover, selective transport also is required for carrying out cellular mechanisms, since this mechanism enables the entry and the exit of macromolecules used by the cell to maintain its function and structure.  

The most common mechanisms of selective transport are diffusion and transport active. Endocytosis and exocytosis are active transport process where proteins, lipids, and different types of macromolecules are transported to both sides of the cell membrane through vesicles. Polar molecules (such as for instance, calcium and iron ions) may be transported via transport active, while hormones and vitamins may be transported via passive diffusion.