Download Transportation Through the Plasma Membrane

Transportation Through the Plasma Membrane Name: _________________
Date: _______ Period: ____
1.
Maintaining a Balance
 _____________________ - internal balance
 ________________ _________________ - allows some materials to pass through membrane
while rejecting others.
2.
Fluid-Mosaic Model
 This description is of a ________________
_____________ that is made up of molecules that are free to flow
among one another.
 The kinds and arrangements of proteins
 And lipids vary from one membrane to another and give each type
of membrane specific ________________ properties.
3.
Structure of the Plasma Membrane
 Two-layered structure
 Lipid bilayer
 Made of _________ molecules with _________ molecules in the lipid layer.
 _________________ aid in the movement of materials through the membrane.


The lipids have two fatty acids attached to ________________ and a ________________
________ (phospholipid).
The ___________ “head” of a phospholipid molecule contains a polar _______________
group, and two “tails” are long, nonpolar ___________ chains.
4.
Proteins of the Plasma Membrane
a.
_______________ proteins
b.
_______________ proteins
5.
Transport Proteins (require energy)
a.
______________ proteins: channel for lipid insoluble
molecules and ions to pass freely through.
b.
______________ proteins: bind to a substance and carry it across membrane, change shape in
process.
6.
Receptor Proteins
- Bind to chemical messengers (ex. Hormones)
which sends a message into the cell causing cellular reaction.
9.
How do materials move into and out of the cell?
a.
Materials must move in and out of the cell through the
__________________________________.
b.
Some materials move between the _______________________________.
c.
some materials move through the ________________________________.
10.
Plasma Membrane Transport – Molecules move across the plasma membrane by:
________________________ and _______________________
11.
What are the three types of PASSIVE transport?
a.
____________________________
b.
____________________________
c.
____________________________
A.
Diffusion – also called Brownian Motion: random motion of molecules.
(Robert Brown, a Scottish scientist, used
a microscope to observe tiny particles
suspended in water. He noticed that the
particles moved constantly in little jerks
as if being struck by invisible objects.
This motion is called Brownian Motion)
- all objects in motion have kinetic energy.


Diffusion is the net movement of molecules from a ________________ concentration to a
__________ concentration until equally __________________.
Diffusion rate is related to __________________, ________________, state of matter, size
of ________________________________, and surface area of membrane.
o Dynamic Equilibrium – a continuous movement of molecules, but no change in
______________________________.
- Concentration Gradient – The difference in concentration of a substance across a _______________.
B.
Facilitated Diffusion – Molecules can move directly through the
___________________________.
What is facilitated diffusion?
- the net movement of molecules from a __________ concentration to a ______ concentration
with the aid of ______________ or _____________ proteins.
C.
Osmosis - _________________ molecules can move directly through the
______________________ of the plasma membrane.
What is osmosis? – diffusion of _________________ molecules through a membrane from an
area of ________________ water concentration to _________________ water concentration.
Osmosis in Action
What will happen in
the U-tube if water
freely moves through
the membrane but the
particles can not pass?
Water moves from the
side with _________
concentration of water
to side with __________
concentration of water.
movement stops when
_________ pressure
equals __________________ pressure.
1.
Osmosis and Tonicity
* Tonicity refers to the total ____________ concentration of the solution
______________ the cell.
What are the three (3) types of tinocity?
- ________________________________
- ________________________________
- ________________________________
Isotonic – solution in which the concentration of _________________(solvent) outside the cell is the
___________ as the concentration inside the cell.
What will happen to a cell placed in an isotonic solution??????????
- The cell will have no net movement of ___________
and will stay the same _____________.
Hypotonic (_______ Concentration) – solution in where concentration
of ___________ (solvent) outside the cell is ______________ than the
concentration inside the cell.
What will happen to a cell placed in hypotonic solution???????????
- The cell will _________ water and ________________.
- If the cell bursts, then we call this ____________. In plants we
call this ___________ pressure.
Hypertonic (______________ Concentration) – solution in which concentration of ___________ (solvent)
outside the cell is ________________ than the concentration inside the cell.
What will happen to a cell placed in a hypertonic
Solution???????????
- the cell will _________ water and ________.
In plant cells, the central vacuole will shrink
and the plasma membrane will pull away from
the cell was causing the cytoplasm to shrink
called ___________________.
12.
What are three types of Active Transport?
a.
________________________________
b.
________________________________
c.
________________________________
- Phagocytosis
- Pinocytosis
*ATP energy is ____________ to move the molecules through.
A.
Active Transport – molecules move from areas of __________
concentration to areas of ___________ concentration with the aid of _________ energy.
Importance of Active Transport
 Bring in essential molecules
 Rid cell of unwanted molecules (Ex. Sodium from urine in kidneys)
 Maintain internal conditions different from the environment
 Regulate the volume of cells by controlling _____________ pressure.
 Control cellular ____

Re-establish concentration gradients to run ______________ diffusion. (Ex.
________________-____________ pump and proton pumps)
B.
Exocytosis (EXO - ________) – movement of large molecules bound in vesicles _________ of
the cell with the aid of ______ energy. Vesicle fuses with the plasma membrane to eject
macromolecules.
Ex. Proteins, polysaccharides, polynucleotides, whole cells, hormones. Etc
C.
Endocytosis (ENDO - _____) – movement of large molecules ________ the cell by engulfing
them in vesicles, using _______ energy.
* Two types of endocytosis
1.
_____________________
2.
_____________________