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Selecive permeability is important because it keeps cells functioning properly by letting only wanted molecules (solutes) in and unwanted solutes out.

In addition to keeping the "bad stuff" out (e.g. bacteria, viruses), selective permeability is essential to the function of our nervous system. Without it, our neurons would not "fire". This is because selective permeability (think sodium potassium protein pump and active transport that requires ATP), creates a negative membrane potential. At rest potassium ions flow out but the membrane is impermeable to sodium ions. Neuron to neuron signaling occurs when there is a depolarization at an axon that causes the permeability to temporarily "switch" so that potassium and sodium ions can enter the cell. This triggers an action potential which jumps along nerve cells. This action potential is converted into a chemical signal as it triggers a calcium ion influx which in turns triggers the production and transportation of neurotransmitter-vesicles, and exocytosis into the synapse between neurons. Receptors on the adjacent neuron receive the neurotransmitter and the "signal" is communicated onwards. Protein pumps return levels of Na, K and CA to "resting" levels awaiting the next signal. Without selective permeability gradients of Na, K, CA and other ions could not be created to "drive" these and other processes.

There is much more that can be said about selective permeability. It allows glycoproteins to sit in the cell membrane and act as antibodies and glycolipids to act as signals on the cell membrane. Proteins embedded in the cell membrane can change shape and respond to feedback loops controlling the influx and efflux of substances and maintaining homeostasis.

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Q: Why is selective permeability important?
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Related questions

What is the characteristic of a cell membrane that controls which substances that can either enter and exit the cell?

Selective permeable


What is the importance of selective permeability in a cell?

It avoids the entry of unnecessary substances.It is important in protection and efficient function.


How does selective permeability maintain homeostasis?

The selective permeability of a cells membrane helps the cell to maintain homeostasis because it controls what goes in and out of the cell. This is extremely important for the health of the cell.


Is selective permeability important to cell membranes?

Yes, it's a major factor in maintaining the internal environment of cells.


Which layer controls selective permeability?

The cell membrane controls selective permeability. Larger substances can enter the cell through endocytosis and exit through exocytosis.


Why is selective permeability necessary for the cell to survive?

GENETICS


What does Selective permeability do?

It allows the passage for certain substances.


When some substances can pass across them but others can not what are biological membranes said to have?

selective permeability or semi-permeability


When some substance can pass across them but others can not biological membranes are said to have?

selective permeability or semi-permeability


When some substances can pass across them but other can not biological membranes are said to have?

selective permeability or semi-permeability


Selective permeability refers to the fact that the plasma membrane keeps all molecules out of the cell?

Selective permeability refers to the fact that the plasma membrane can choose which molecules to let in or out of the cell.


How does a sieve colander demonstrate the property of selective permeability?

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