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35 Cards in this Set
- Front
- Back
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What are the two types of membrane transport?
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Passive and Active
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What is passive transport?
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Passive transport does not require energy and substance moves down its concentration gradient
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What is active transport?
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Active transport requires energy (ATP)
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What are the three types of passive transport?
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Simple Diffusion, Facilitated Diffusion and Osmosis
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What is carrier-facilitated diffusion?
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Trans-membrane integral proteins carry large non-lipid soluble solutes (like sugars and amino acids)
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What is channel-facilitated diffusion?
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Trans-membrane proteins that form channels transfer ions or water
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What is osmosis?
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Osmosis is the specialized diffusion of water through the membrane or through aquaporins
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What is simple diffusion?
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Simple diffusion is the unassisted diffusion of non-polar, lipid soluble solutes passing through the membrane
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What is a solute?
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A solute is the substance being dissolved in a solution
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What are some examples of solutes that can pass directly through the membrane?
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Sex hormones, oxygen, fat-soluble vitamins, steroid hormones
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What are two different types of channels?
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Leak channels and gated channels
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What are leak channels?
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Leak channels are always open
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What are gated channels?
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Gated channels open due to electrical or chemical signals
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Why can't ions diffuse directly through the membrane?
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Because they are positively charged. The charge is repelled by the phospholipid bilayer
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What is osmolarity?
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Osmolarity is the total concentration of all solute particles in a solution
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What is the normal osmolarity of body fluids?
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300 mOsm (milliosmolar)
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What should the osmolarity be of a typical healthy adult both inside and outside a cell?
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300 mOsm
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What is 1 Molar NaCl equal to?
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2 Osm NaCl
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What is tonicity?
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Tonicity is the measure of the ability of an extracellular solution to change the shape of cells by causing them to lose or gain water
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What is an isotonic solution?
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The ECF has the same osmolarity as the ICF or cytosol
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What happens to a cell in an isotonic solution?
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Cell neither gains nor loses water. It does not change shape
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What is a hypertonic solution?
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The ECF solution has a greater solute concentration than the ICF
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What happens to a cell in a hypertonic solution?
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Cell loses water and shrinks (crenates)
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What is a hypotonic solution?
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The ECF solution has a lower solute concentration than the ICF
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What happens to a cell in a hypotonic solution?
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Cell gains water and swells. It may burst (lyse)
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What is hemolysis?
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The bursting of red blood cells
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What is primary active transport?
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Transports solutes AGAINST their concentration gradient.
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What does "against their concentration gradient" mean?
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From low concentrations to high concentrations
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What is the most common example of primary active transport?
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Na+/K+ pump
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What is a Na+/K+ pump?
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It is a globular functional protein that pumps Na+ out of the cell and K+ into the cell.
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What occurs if a 100 mOsm NaCl solution is separated from a 300 mOsm NaCl solution by a membrane that is permeable only to water but not Na+ or Cl-?
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The water diffuses from the 100 mOsm to the 300 mOsm solution
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What is vesicular transport?
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Sacs called vesicles uses ATP to transport fluids with large particles across cell membrane
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What is exocytosis? What is secretion?
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Ejecting substances FROM inside the cell. Secretion is an example of exocytosis
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What is endocytosis?
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Moving substances INTO the cell
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What is phagocytosis?
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Phagocytosis is an example of endocytosis where macrophage eats a bacterium or virus
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