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8.1 Fill in the blank notes
Cellular transport
Osmosis: Diffusion of Water
• Diffusion is the movement of particles from an area of _________________
concentration to an area of ____________________ concentration.
• In a cell, water always moves to reach an __________________ concentration on
both sides of the membrane.
• The diffusion of water across a ___________________ permeable membrane is
called _________________.
• Regulating the water flow through the plasma membrane is an important factor in
maintaining ___________________ within a cell.
What controls osmosis?
• Unequal distribution of particles, called a concentration __________________, is
one factor that controls osmosis.
Cells in an isotonic solution
 Most cells whether in multicellular or unicellular organisms, are subject to osmosis
because they are surrounded by ______________ __________________.
• In an _________________ solution, the concentration of dissolved substances in
the solution is the same as the concentration of dissolved substances inside the
cell.
• In an isotonic solution, water molecules move into and out of the cell at the same
__________________, and cells retain their ____________ shape.
• A plant cell has its normal shape and pressure in an isotonic solution.
Draw a picture of figure 8.2 A & C on pg. 197 below:
Isotonic solution
Plant cell in an isotonic solution
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Cells in a hypotonic solution
• In a hypotonic solution, water ________________ a cell by osmosis, causing the
cell to _______________.
• Plant cells swell beyond their normal size as ____________________ increases.
Draw Figure 8.3 A & C on pg. 197 below:
Hypotonic solution
Plant cells in a hypotonic solution
Cells in a hypertonic solution
• In a hypertonic solution, water _______________ a cell by osmosis, causing the
cell to __________________.
• Plant cells _______________ pressure as the plasma membrane
___________________ away from the cell wall.
Draw a picture of figure 8.4 A & C on pg 197 below
Hypertonic solution
Plant cell in a hypertonic solution
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Passive Transport
• When a cell uses no energy to move particles across a membrane
_______________________ transport occurs.
Passive Transport by proteins
• _________________ transport of materials across the membrane using transport
protein is called _______________ diffusion.
• Some transport proteins, called __________________ proteins, form
______________________ that allow specific molecules to flow through.
• The movement is with the ____________________ gradient, and requires
________ energy input from the cell.
• Carrier proteins change _________________ to allow a substance to pass through
the plasma membrane.
• In facilitated diffusion by carrier protein, the movement is _______________ the
concentration gradient and requires _____________ energy input from the cell.
• Draw the 3 ways passive transport can occur. (figure 8.5 A, B, & C on
pg.198) Be sure you label the direction of the concentration gradient and the
direction the particle is moving.
Simple diffusion
Facilitated diffusion by carrier
protein
Facilitated
diffusion by
channel
proteins
Active Transport
• Movement of materials through a membrane _______________ a concentration
gradient is called active transport and requires __________________ from the
cell.
How active transport occurs
• In active transport, a transport protein called a _________________ protein first
_____________ with a particle of the substance to be transported.
• Each type of carrier protein has a ______________ that fits a specific
__________________ or ion.
• When the proper molecule _____________ with the protein, chemical
______________ allows the cell to change the ________________ of the carrier
protein so that the particle to be moved is released on the _____________
________________ of the membrane.
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•
•
Once the particle is released, the protein’s original ______________ is restored.
Active transport allows particle movement into or out of a cell
____________________ a concentration gradient.
Draw Figure 8.6 on pg 199. Be sure to label the direction of the concentration
gradient and the direction the particle is moving:
+
Cellular
energy
Transport of Large Particles
• ____________________ is a process by which a cell surrounds and takes in
material from its environment.
• The material is ________________ and ___________________ by a portion of
the cell’s plasma membrane.
• The resulting ___________________ with its contents moves to the
________________ of the cell.
• ____________________ is the expulsion or secretion of materials from a cell.
• Endocytosis and exocytosis both move masses of material and both require
__________________.
Draw figure 8.7 on pg. 200 below. Be sure to label endocytosis and exocytosis:
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