# What two processes allow materials into and out of cells?

Feb 18, 2018

#### Explanation:

Diffusion is the movement of substances from a higher concentration to a lower concentration, to create a chemical equilibrium. An example of diffusion that happens in plants is the movement of carbon dioxide in the air and into the plants for photosynthesis.

Osmosis is the diffusion of water through a partially permeable membrane. An example of osmosis in plants happens in the root hair cells, where they take in water, to make the plant turgid and stable in shape.

Here is a video which describes how osmosis impacts onion cells placed into tap water and then into a salt water solution.

Active transport is the opposite of diffusion, it is the movement of substances from a lower concentration to a higher concentration. However, this process requires energy, and plants use $A T P$ to perform it. An example would be getting nitrates and other ions from the soil for the plant, for making proteins and other substances.

I hope this helps!

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