Term
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Definition
| a complex barrier seperating the cell from its external environment |
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Term
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Definition
| True or False - a cell can survive if it is totally isolated from its environment |
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Term
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Definition
| the cell membrane functions like a ____, controlling what ____ and ____ the cell |
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Term
Selectively permeable or Semi-permeable |
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Definition
| Some substances cross the cell membrane easily, while others need help crossing, and some can't cross at all. This means that the cell membrane is ______ or _______. |
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Term
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Definition
| Cell membranes are made mostly of ________ molecules (lipid-glycerol & 2 fatty acid tails attached to a phosphate group or head). |
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Term
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Definition
| The phosphate heads of a phospholipid are _____ so therefore they are ______ ... so they orient themselves toward areas of water. |
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Term
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Definition
| The lipid tails of a phospholipid are ______ so therefore thay are ________ ... so they orient themselves away from water, resulting in being sandwiched between two layers of phosphate heads. |
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Term
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Definition
| The cell membrane is constantly being ______ and ______ ______ in living cells. |
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Term
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Definition
| A variety of ______ are embedded in the phospholipid bilayer. |
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Term
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Definition
| proteins attached to the surface (internal or external) of the cell membrane, but not embedded inside the membrane. |
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Term
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Definition
| proteins embedded in the phospholipid bilayer |
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Term
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Definition
| True or False - some integral proteins extend across the entire cell membrane and are exposed to both the inside of the cell and the exterior environment |
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Term
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Definition
| True or False - some integral proteins extend only to the inside or only to the exterior surface of the cell membrane |
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Term
Cell Surface Makers, Receptor proteins, and Transport proteins |
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Definition
| 3 types of integral proteins |
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Term
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Definition
integral proteins that act as recognition sites ... often have carbohydrates attached, which serve as identification badges hepling cells recognize each other and may also act as sites where viruses and chemical messages (ex. hormones) can attach |
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Term
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Definition
| integral proteins that allow other molecules to attach |
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Term
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Definition
| integral proteins where some act as channels/pores that molecules pass through, while other types bind to a substance and then change shape, pulling the substance bound to it thru the membrane as it changes shape |
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Term
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Definition
| Proteins in and on the membrane form _______ or _______. |
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Term
moving,
changing,
Fluid Mosaic Model |
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Definition
| The cell membrane is fluid and the proteins and lipids are constantly _____ and the patterns are constantly _____, so scientists call this modern view of membrane structure the ______ ______ ______. |
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Term
| the materials that enter and exit the cell |
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Definition
| The activities of a cell depend on ________________. |
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Term
uncharged, proteins and carbohydrates |
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Definition
| Small ______ molecules such as oxygen and H20 can cross the membrane easily, but large molecules such as ______ , ________ , and ions can't pass without help. |
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Term
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Definition
| the net movement of molecules from an area of greater concentration to an area of lower concentration |
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Term
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Definition
| A _______ ________ is the difference between the concentration of a particular molecule in one area and the concentration of it in the adjacent area. |
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Term
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Definition
| Diffusion always occurs ______ a concentration gradient, moving from an area of great concentration to an area of lesser concentration. |
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Term
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Definition
| the diffusion of water across a semi-permeable membrane |
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Term
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Definition
| Osmosis occurs in response to the concentration of _______ dissolved in water. |
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Term
False Water moves toward the more concentrated solute area, while the solute moves to the less concentrated solute area. |
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Definition
| True or False - Water moves toward the less concentrated solute area, while the solute moves to the more concentrated solute area. |
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Term
| hyperosmotic (hypertonic) |
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Definition
| If a cell is in a _______ solution then the concentration of solute is greater outside the cell, so water moves out of the cell. |
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Term
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Definition
| Animal cells in a hyperosmotic(hypertonic) solution crenate (plasmolysis in plant cells) or ______. |
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Term
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Definition
| If a cell is in a ________ solution then the concentration of solute is lower outside the cell, so water moves into the cell where there is more solute. |
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Term
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Definition
| An animal cell in a hypoosmotic (hypotonic) solution will lyse(cytolysis) or ______. Plants cells will become turgid(tugor pressure) or ______. |
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Term
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Definition
| If a cell is in a _______ solution then the concentration of the solutes inside equal the solutes outside the cell, so movement occurs in and out at an equal rate. |
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