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18 Cards in this Set
- Front
- Back
What is homeostasis?
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Homeostasis is the Bodys ability to maintain relatively constant conditions internally, regardless of external conditions.
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What is POSITIVE feedback? example?
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Positive feedback is when the response to change in the variable being regulated causes the variable to get farther away from normal. EX: labor, blood clotting, ovulation
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What is NEGATIVE feedback? example?
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Negative feedback is when the response to change in a variable being regulated causes the variable to get back to normal. EXAMPLE: sweating
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Which is sensor and which is motor: afferent and efferent.
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Afferent SENSES the measure and brings it to the brain to create a response. Efferent is MOTOR--brings variable back to normal.
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Are polar compounds hydrophobic or hydrophillic?
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Polar compounds are hydrophillic...they will dissolve in water. Polar compounds include water and ions.
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Are non-polar compounds hydrophillic or hydrophobic? What is an example?
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Non polar compunds are hydrophobic. They are lipids...they will not dissolve in water, but can dissolve in other lipids.
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What is the structure of the plasma membrane?? What does each component do?
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1) Phospholipids-have either polar or non polar ends
2) Proteins- act as a carrier, transports things in and out of the cell, form channels and pores 3) Cholesterol- stabilizes the plasma membrane, keeps things in right place 4) Carbohydrates for CELL RECOGNITION |
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What is diffusion?
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Solute goes from greatest area of concentration to lowest area of concentration until it reaches equilibrium.
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What variables affect diffusion?
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Size of molecule, concentration gradient, temperature.
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What is osmosis?
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Osmosis is the diffusion of water through a selectively permeable membrane. Penetrating substances can go right thru membrane..non penetrating cannot...they are either too large or charged.
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What ions are typically found inside the cell?
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Potassium is typically found inside the cell.
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What ions are typically found outside the cell?
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Sodium, Calcium, Chloride
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What are the 5 membrane transport mechanisms?
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1) Endo/exocytosis
2) Diffusion thru lipid bilayer 3) Diffusion thru protein channels (water/water soluble molecules) 4) Faciliated diffusion 5) Active transport |
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What is osmotic pressure?
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The amt of pressure needed to prevent the net flow of water into the solution
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What is osmoloritty?
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Osmolarity is the number of particles per liter of solution (penetrating and non penetrating)
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The ______the osmolarity of the solution, the greater the __________.
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The greater the osmolarity of a solution, the greater the osmotic pressure.
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What is tonicity?
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IT IS NOT A NUMBER. its an adjective to describe a solution with respect to its effect on a cell in the solution. HYPO...ISO...HYPER
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what is osmosis affected by?
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the permeability of the membrane, the concentration gradients of the solutes, the pressure gradient across the cell membrane
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