Download Membrane Transport

Check In
1. Outline the functions of membranes. [2]
2. Define phospholipid. [1]
Homework
Study for your test on Friday Oct. 5
Check In
1. Define diffusion. [1]
2. Outline how your test preparation is going using
supportive language.
Possible sentence frames:
It is my opinion that __ because __.
I believe __ because __.
Homework
Study for your test on Friday Oct. 5
Check In
1. Define osmosis. [1]
2. Outline an example of osmosis.
Homework
Cut out your cell membrane
Check In
Outline the process shown below. [2]
Before:
After:
Check In
Outline the process shown below. [2]
Markscheme:
1. Osmosis
2. Water leaves the cell
3. Hypertonic solution
outside of the cell
4. Plasmolysis
2–4
The elements or compounds produced by a
chemical reaction are known as
1.
2.
3.
4.
reactants.
enzymes.
products.
waste.
Copyright Pearson Prentice Hall
2–4
Chemical reactions always involve
1.
2.
3.
4.
changes in energy.
enzymes.
catalysts.
changes in the atomic number of the reactants.
Copyright Pearson Prentice Hall
2–4
The factor that prevents many energy-releasing
reactions from occurring at relatively low
temperatures is called
1.
2.
3.
4.
catalytic energy.
chemical bond energy.
enzyme energy.
activation energy.
Copyright Pearson Prentice Hall
2–4
Which of the following statements is true?
1.
2.
3.
4.
All proteins are enzymes.
All catalysts are enzymes.
All enzymes are catalysts.
All catalysts are proteins.
Copyright Pearson Prentice Hall
2–4
What happens to an enzyme after the reaction it
catalyzes has taken place?
1. The enzyme is destroyed, and the cell must make
another.
2. The enzyme holds on to the product until another
enzyme removes it.
3. The enzyme is unchanged and ready to accept substrate
molecules.
4. The enzyme changes shape so it can accept a different
kind of substrate.
Copyright Pearson Prentice Hall
Notes –
Membrane
Transport
Passive transport
• Movement of molecules across a membrane
without using energy
• Types:
– Diffusion
– Osmosis
– Facilitated diffusion
Diffusion
• Movement of molecules from high
concentration to low concentration
• Equilibrium = the concentration is the same
on both sides of the membrane
Review #1
If a substance is more highly concentrated outside
the cell than inside the cell and the substance can
move through the cell membrane, the substance
will
1. move by diffusion from inside the cell to
outside.
2. remain in high concentration outside the cell.
3. move by diffusion from outside to inside the
cell.
4. cause water to enter the cell by osmosis.
Review #3
Describe what is happening…
Review #3
Describe what is happening…
Review #4
Describe what is happening…
Review #4
Describe what is happening…
Osmosis
• Movement of water molecules across a
membrane from high water concentration to
low water concentration
Fingersurvey:
Where is there a
1
2
high water
concentration?
To which number
will water move?
Osmosis
• Movement of water molecules across a
membrane from high water concentration to
low water concentration
Osmosis
• Movement of water molecules across a
membrane from high water concentration to
low water concentration
• Hypertonic = higher solute concentration
• Hypotonic = lower solute concentration
• Isotonic = equal solute concentration
Review…
1
2
Glucose
molecules
Facilitated Diffusion
• Diffusion of molecules
across a membrane through
protein channels
Protein
channel
Review
Describe what
is happening…
Review
Describe what
is happening…
Concentration Gradient
• A difference in concentration on either side of
a membrane
Active transport
• Movement of
molecules across a
membrane using
energy
• Movement of
molecules from
low concentration
to high
concentration
• Active transport is
done by protein
pumps
Molecule to be carried
Last Review
The process by which molecules diffuse
across a membrane through protein channels
is called
1. active transport.
2. endocytosis.
3. facilitated diffusion.
4. osmosis.
Copyright Pearson Prentice Hall
Check Out
1. Define osmosis (use the word concentration in
your definition). [1]
2. Outline an example of osmosis. [1]
Homework
Study for your test on Friday Oct. 5
Warm up
1. Define active transport. [1]
2. Outline the relationship between active
transport and concentration gradients. [2]
Homework
none
Warm Up
• What is an analogy for surface area in a cell?
• What is the relationship between cell size and
the surface area to volume ratio? Why is it
important?
Warm Up
• What was the smallest object from the
homework last night? What is the definition?
• What was the shortest inverse location?
• What was the longest inverse location?