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Published byLoren Robertson Modified over 8 years ago
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Mr. Drake
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Membrane is “_____________________”: only allows certain things to enter the cell The lipids prevent too much water from entering or exiting the cell Small, uncharged, molecules pass through easily (O 2, CO 2 ).
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Concentration of molecules is equal inside the cell and outside of the cell This is how we achieve homeostasis The cell is always moving towards equilibrium Concentration – amount of molecules in a given space Example: 5 grams/liter
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Transport that does NOT require energy 1) 2) 3)
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Simplest type of transport Movement of molecules from an area of _______________________(MORE)to an area of ______________________(LESS) ______________________: difference in concentration of molecules across a space Molecules move down their concentration gradient Molecules will do this without energy
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Cell membranes are selectively permeable Go from high concentration to low concentration Depends on the size of the molecule, smaller is better Calcium, sodium and water pass easily
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Movement of _________ across the cell membrane Again, it goes from high to low concentration Does not require energy it is passive
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_____________: having a lower solute concentration, and therefore a higher water concentration, relative to another solution. Example: If the cell is sitting in a hypotonic solution, then water will flow into the cell. _____________: Having a greater solute concentration, and therefore a lower water concentration, relative to another solution. If the cell is sitting in a hypertonic solution, then water will flow out of the cell.
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Direction of osmosis HypotonicWater into the cell HypertonicWater out of the cell Isotonic = Into and out of the cell at equal rates Solution outside of cell Direction of Osmosis _____________-having an equal solute concentration and water concentration relative to another solution. If a cell is sitting in an isotonic solution, water will flow into and out of the cell at equal rates.
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Most get to equilibrium easily as water passes across membranes Cells live in a ______________ environment, water all around them If too much water enters the cell it will burst Cells must manage water and solute levels to prevent dehydration
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For molecules that can’t pass through the membrane Either too large or not lipid-soluble Proteins in the membrane help push them through From high to low concentration The proteins will change their shape and this pushes the molecules through
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Ion channels in the cell membrane act like gates in a fence Allow sodium, calcium, potassium, and chloride to flow into cell (Ca+, K+, Cl-) Useful in nerve and muscle cells
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1) Sodium-Potassium Pump 2) Endocytosis 3) Exocytosis
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From _________________concentration— AGAINST concentration gradient Uses energy-Active 1) ______________________: in muscle cells uses energy Creates electrical impulses like in nerve cells
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Push proteins and hormones “up” the concentration gradient Key to survival of animal cells Sodium potassium pump: Animals must have more sodium outside and potassium inside to allow for energy production in cells Can move small and large molecules using this method
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2) ________________: large molecules like food into the cell 3)________________: Large molecules out of the cell
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Opposite of endocytosis, cell releases large amounts of material through the membrane Removes waste from the cell Important to maintaining homeostasis in cells
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Cells of animals live in a salty or “saline” solution This allows them to survive in a variety of different environments Cells must maintain fluid levels or they die Most animals will have a kidney type organism to manage these levels in the body
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Filter the blood of animals through osmosis and diffusion Prevent dehydration and maintain fluid levels Prevent toxins from building up in the blood Eliminate swelling in the body
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When Kidneys fail harmful toxins build up in the blood CKD (chronic kidney disease), cancer, aging and drug/alcohol abuse lead to kidney failure Tubing that removes toxins, Takes 3-4 hours 3 times a week
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