Cell Membrane Transport

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Cell Membrane Transport
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Cell membrane transport

• There are 2 types of cell membrane transport
• Passive Transport
• Things flow from
• High to low
• Active Transport
• Things flow from
• Low to high

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Another perspective on passive and active
transport
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Passive Transport

• Diffusion
• The movement of particles from areas of high
  concentration to low concentration
• http//www.indiana.edu/phys215/lecture/lecnotes/d
  iff.html
• http//www.biosci.ohiou.edu/introbioslab/Bios170/d
  iffusion/Diffusion.html

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Equilibrium

• When is equilibrium reached when discussing cell
  membrane transport
• When the concentrations of particles are the same
  on both sides

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Facilitated Diffusion

• Particles flow from high concentration to low
  concentration but this time they need the help of
  proteins to get through the cell membrane.

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Facilitated diffusion
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Passive transport

• Osmosis
• The diffusion of water across a selectively
  permeable membrane
• Important in maintaining cell homeostasis
• Water flows to side of membrane where the water
  concentration is lower until equilibrium is
  reached

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Osmosis

• Osmosis is controlled by the amount of solutes on
  either side of a membrane

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Remember this is important Osmosis deals with
what

• The movement of particles
• The movement of glucose
• The movement of water
• The movement of lipids

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Osmosis Types of Solutions

• When dealing with osmosis water can either move
  into the cell or out of it.
• The solute can not move to equal out the solution
  so the water has to.
• We describe the solutions that cells are in as
  either hypotonic isotonic or hypertonic.

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What are the concentrations
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Isotonic Solution

• Isotonic solution Concentration of solute is
  the same in the cell and the area around the
  cell.
• Give me an example of an isotonic solution that
  some of you use everyday

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Isotonic solution
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Hypotonic Solution

• Hypotonic Solution Concentration of solute is
  lower in the solution than in the cell.
• Where is water going to move in order to reach
  equilibrium (Equal concentrations)
• Inside the cell

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Hypotonic solutions

• Since water moves into the cell the cell can
  explode
• http//www.tvdsb.on.ca/westmin/science/sbi3a1/Cell
  s/Osmosis.htm
• So Hypotonic solution low concentration of
  solute cell can explode

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Plant and animal cells in a hypotonic solution
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Hypertonic Solution

• Hypertonic solution concentration of solute is
  higher in the solution than in the cell.
• Where is water going to move in order to reach
  equilibrium (Equal concentrations)
• Outside the cell

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Hypertonic solutions

• Since water moves out of the cell the cell will
  shrink
• http//www.tvdsb.on.ca/westmin/science/sbi3a1/Cell
  s/Osmosis.htm
• So Hypertonic solution high concentration of
  solute cell will shrink

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Plant and animals cells in a Hypertonic Solution
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Osmosis

• http//www2.nl.edu/jste/osmosis.htm
• http//www.coolschool.ca/lor/BI12/unit4/U04L06/rbc
  .html

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The following diagram demonstrates what type of
solution
solute

• Hypotonic
• Isotonic
• Hypertonic

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In the following diagram which way is water going
to move
solute

• Inside the cell
• Outside of the cell
• Both 1 and 2

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The following diagram demonstrates what type of
solution
solute

• Hypotonic
• Isotonic
• Hypertonic

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In the following diagram which way is water going
to move
solute

• Inside the cell
• Outside of the cell
• Both 1 and 2

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Active Transport

• Molecules move from low concentration to high
  concentration
• Requires energy.why

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Other membrane transport activities that require
energy

• Endocytosis
• Engulfing of large particles or liquids from
  outside the cell

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2 types of Endocytosis

• Phagocytosis
• Engulfing of large particles
• from outside the cell
• Pinocytosis
• Engulfing of
• liquids from
• outside the cell

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Other membrane transport activities that require
energy

• Exocytosis
• Release of large particles or liquids from inside
  the cell

Outside the cell
Inside the cell
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This diagram is an example of what membrane
transport

• Diffusion
• Facilitated diffusion
• Endocytosis
• Exocytosis

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This diagram is an example of what membrane
transport

• Diffusion
• Facilitated diffusion
• Endocytosis
• Exocytosis