2.03 Activity
FLIP
Name: _______________________ Date: __________
FLOP
Name the properties that cells work to
Homeostasis is one of the 8 characteristics of maintain through homeostasis:
living things. Homeostasis is the
maintenance of the internal environment
within certain limits.
Cells must maintain a number of limits.
What would happen if your body did not
These include properties like temperature,
maintain homeostasis?
salinity, pH, blood glucose level, the
concentrations of other nutrients and
wastes, and water balance.
Temperature
What is the term used to describe enzymes
Enzymes have a small part called the active site that no longer work due to temperature
where substrates bind and the chemical
changes?
reaction takes place. Only molecules with the
correct shape can fit with the enzyme. The
shape of the active site is changed by heating
the enzyme above a certain temperature. Then
the molecules can no longer fit and the
reaction cannot happen.
pH
A measure of the degree of the acidity or the
alkalinity of a solution as measured on the pH
scale of 0 to 14. Parts of the cells work best at
specific pHs.
Glucose Concentration in the Blood
Cells want to maintain the same glucose
balance in and out of cells. When there is
excess glucose that the cells do not want inside,
it is stored in special cells in the liver or turned
into lipids. Insulin, a hormone, helps regulate the
amount of glucose in our blood.
Why does a cell need to maintain
temperature and pH?
What happens to excess glucose in the
bloodstream?
Water Balance
The body’s cells are bathed in water, and the
correct water balance is crucial to life. Water
crosses easily across most membranes.
Cell membranes are what regulate things like pH,
glucose, and water balance.
Cells have semi-permeable membranes which
allow some things to pass through but prevent
other things from passing through. Cell
membranes will allow small molecules like
oxygen, water, carbon dioxide and glucose to
pass through. Cell membranes will not allow
larger molecules like starch and proteins to pass
through.
What molecules does the cell membrane let
through?
What molecules does the cell membrane
prevent from passing through?
Name: _______________________ Date: __________
What structures do you see embedded in the
cell (plasma) membrane?
The cell membrane controls what goes in and what
goes out of the cell. The movement of molecules
across the membrane is called transport.
There are different types of transport, but all
molecules are moving in relation to a concentration
gradient, a measure of how the concentration of
particles changes from one area to another
Label the area of HIGH and LOW concentrations.
There are two main types of transport: Active and
Passive.
Active transport involves the use of energy.
Substances are moved AGAINST the concentration
gradient, from an area of LOW concentration to
HIGH concentration.
Active transport generally requires the use of
“protein pumps” to move molecules.
Passive Transport does not require energy.
Substances are moved WITH the concentration
gradient, from areas of HIGH concentration to LOW
concentration.
There are 3 types of passive transport:
1) Diffusion: Passive transport from high to low
concentration
2) Osmosis: Diffusion of water through a
selectively permeable membrane
3) Facilitated Diffusion: Passive transport of
specific molecules (like glucose) across the
membrane with the help of protein channels
Sample Problem…
Cup of water
cell
What is the major difference between active
transport and passive transport?
What is the relationship between diffusion and
osmosis?(Hint: what is the only substance that
carries out osmosis?)
Which of the following is NOT an example of active
transport?
I.
Facilitated diffusion
II.
Osmosis
III.
Diffusion
A. I only
B. III only
C. I and II only
D. I, II, and III
Where is there the highest concentration of water?
Which way will the water move?
What will happen to the cell if it gains water?
What will happen to the cell if it loses water?
Name: _______________________ Date: __________
Directions: Go to the following website and use the animation to answer the following questions.
http://programs.northlandcollege.edu/biology/biology1111/animations/passive1.swf
Membrane: draw and label a picture of the membrane below
How does the lipid bilayer allow for selective permeability?
Passive Transport
Simple Diffusion:
What is simple diffusion? (define and draw a picture)
What is a concentration gradient? (draw and label the graph)
Rate of diffusion is dependent on what?
Facilitated Diffusion:
What is facilitated Diffusion?
Osmosis:
What is osmosis?
What are hypotonic and hypertonic solutions? (Draw a picture below and show which direction water will
move)
Name: _______________________ Date: __________
Compare/contrast the different types of passive transport:
Simple Diffusion:
Osmosis:
Facilitated Diffusion:
Active Transport:
What is active Transport?
Why is it necessary?
What is the role of the protein in active transport? What is the role of ATP?
Name: _______________________ Date: __________
Draw which way the water will move:
A.
B.
C.
D.
E.
F.
Drawing [Draw arrows to show which way the materials will move]
Simple Diffusion and Osmosis
A. Particles can move:
B. Particles can move:
D. Particles CANNOT move:
Active Transport
G.
E. Particles CANNOT move:
F. Particles CANNOT move:
H.
I.
Making Predictions
What will happen to the cell if…
Plant
Water moves in
Water moves out
C. Particles can move:
Explanation
Animal
Draw a Picture
Plant
Animal