Active and Passive Transport in Cells – Study Guide
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1. Using the terms particles, movement, high, low, and concentration, define Diffusion.
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____2 (a) Define Osmosis.
(b) compare and contrast diffusion with osmosis. ______________________________________________
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3. The illustration below shows a membrane large enough to let water molecules pass through, but too small for
the sugar (glucose) molecules to pass through. What best describes the movement of the water molecules
in this illustration?
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4. What best explains the REASON for the motion (shown by the arrows) of water molecules in the illustration
below?
Osmosis is occurring and water
travels from the higher concentration of H2O on the left cell – where there is less salt – to the cell
on the right, where there is MORE salt, and therefore a lower concentration of water.
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5. The illustration below shows the passage of particles between the environment and the cell. What best
describes the kind of material/tissue for the cell membrane opening through which the particles are passing.
What is the name of the kind of transport occurring? ____Passive transport is occurring, since it’s
going from high to low concentration.
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6. When particles move up the concentration gradient, they do what? ___use
energy, called active
transport..
What is the concentration gradient? _The percentage of something in a solution, such as 90% water._
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7. When a cell membrane surrounds a particle outside the cell, encloses it in a membrane, and brings it inside the
cell, what process has occurred? Endocytosis.
8. If the concentration gradient for water molecules is higher inside the cell than in its environment, the most
likely way that excess water molecules would depart the cell is by what process? __Osmosis
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____ 10. ATP (the energy substance for the cell) is most likely to be used by the cell in which process? Active
transport
11. Compare and contrast endocytosis with exocytosis: __Both require energy, and represent a form of
active transport. Both move large particles, and need a membrane to work. Endocytosis brings
something INTO the cell, while exocytosis sends particle OUT of the cell.
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12. Make a four frame drawing showing endocytosis:
See board
13. Make a four frame drawing showing exocytosis.
See board, but reverse the steps
14. Provide two examples where exocytosis occurs: __where
a cell sends a package of proteins
out to other cells, or where a cell sends some waste out of the cell.
_______________________________ Provide two examples where endocytosis occurs: Where
a cell
brings in a package of proteins sent by another cell (like cell texting), OR where a
white blood cell attacks and surrounds, then eats an invading virus or bacteria.
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