​They contain:

• Ribosomes

• ​Cytoplasm

• DNA​

• Cell Membrane

RCDC!!!!!

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ALL CELLS HAVE:

NOTE:

Viruses don't have ribosomes; this is why they have to hyjack a cell to reproduce!

​Are around 1/100th the size of a Eukaryotic cell. Examples of prokaryotes are - BACTERIA!

They contain:

• Free-floating DNA

• ​Rybosomes

• Cytoplasm​

• Cell Wall​

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​​Prokaryotic Cell:

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​Are much larger than prokaryotes. Examples include OUR CELLS!

They contain:

• DNA contained in a NUCLEUS

• Cytoplasm

• Membrane-bound organelles and ribosomes

• (in plants) cell walls (not animals​)

​​Eukaryotic Cell

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​Prokaryote versus Eukaryote!

REMEMBER: Pro means "no" nucleus.

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​​Prokaryotic Cell:

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REMEMBER: Eu means "yes" it has a nucleus.

​​Eukaryotic Cell

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​Prokaryote versus Eukaryote Memory Hack

Homeostasis is the term used for BALANCE within a cell (or in an organism). Cells tend to "blend in" and be as similar to their environment. Sometimes they have to counter this to keep stuff they need or eliminate stuff they don't

Do you tend to blend in with people around you?​ Do you have to work to maintain your individuality?

Then you are practicing SOCIAL HOMEOSTASIS!

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Homeostasis

The cell has a semi-permiable​

membrane. This means it only lets SOME THINGS enter or exit while keeping other things out. When water moves freely in and out, this is called OSMOSIS.

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But some of the things it can't pass through are needed; like food or large molecules! So it has special "doors" that allow for it to ​bring in larger molecules.

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Sometimes, too much fluid rushes through the membrane and the cell has to "pump" the excess out so t he cell doesn't lyse (or pop!)​

How does Homeostasis work?​

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When the cell has a higher concentration of water than the environment, that water will flow out of the cell causing the cell to shink.

Hypertonic Environment:

When the environment has the same concentration of water as the cell, the water that leaves the cell is replaced by other water molecules equally. Contact solution is salty so it doesn't harm eye cells as it is perfectly balanced with the salinity of the eyes.

Isotonic Environment:

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When the cell has a lower concentration of water than the environment, that water will flow INTO the cell and can cause it to lyse, or burst!!!

Hypotonic Environment:

​Osmosis and the Environment:

​Cells are effected by the water concentration in their environment.

Remember the lab you did to learn about osmosis? You tested eggs that had their shell removed. You placed them in different conditions (water and syrup) and measured the egg mass and size changes based on their environments. The syrup egg shriveled up and the water egg expanded as water moved in both cups.

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Osmosis Lab