​In the process of diffusion, a substance tends to move from an area of high concentration to an area of low concentration until its concentration becomes equal throughout a space. For example, think about someone opening a bottle of cleaning ammonia in the middle of a room. The ammonia molecules will initially be most concentrated right where the person opened the bottle, with few or no molecules at the edges of the room.

​Osmosis

​In simple words, osmosis is the movement of water from an area of higher concentration to lower concentration through a selectively permeable membrane. A selectively permeable membrane is known as a cell membrane. Osmosis is a simple natural process that occurs all around and inside us, and it's one on which our lives depend. Plants absorb water through osmosis.

​The cell membrane:

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​The cell membrane is capable of receiving and recognizing chemical signals.

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​​The cell membrane separates cellular contents from the outside environment.

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​The cell membrane controls the movement of molecules into and out of the cell.

​Lysosomes are important organelles that help break down, or digest, certain materials inside the cell. Lysosomes have a lot of enzymes that are designed to break down molecules such as proteins and sugars. Once they are broken down, these molecules are sent over to be turned into energy by the mitochondria. Lysosomes will also take all of the dead parts and break them down as well as pass them over for digestion. This is how old cell parts are recycled.