Download Section 7-3 Skeleton Notes

Section 7-3 Skeleton Notes
Name: ____________________________________
Class: __________________
Outside
of cell
Proteins
Inside
of cell
(cytoplasm)
Carbohydrate
chains
Lipid bilayer
FLUID MOSAIC MODEL OF CELL MEMBRANES
The Cell Membrane consists of
___ thin layers of
___________________that
separate the cell's content from
the world around it.
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The TWO Phospholipid
LAYERS are together are
called a
__________________
_____________________.
Membranes are FLUID and have the consistency of vegetable oil if they contain
________________________________ fatty acids.
The Lipids and Proteins of the Cell Membrane are always in motion.
Phospholipids are able to drift across the membrane, changing places with their
neighbor.
Proteins in and on the membrane Form PATTERNS, or mosaics.
Scientists call the modern view of Membrane Structure the ___________ _____________ Model.
Each ___________________ consists of TWO FATTY ACIDS (TAILS), and
PHOSPHATE GROUP (HEADS).
The "Head" is _____________ and Two "Tails" are ___________________.
The two ends of the Phospholipid Molecule have different properties in Water.
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The Phosphate Head is ______________________ meaning "WATER
LOVING", and orient themselves toward water
The Lipid Tails are _________________________ meaning "WATERFEARING", and tend to orient themselves away from water.
MEMBRANE PROTEINS
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A Variety of PROTEIN MOLECULES are EMBEDDED in the Lipid Bilayer.
Integral Proteins exposed to the Cell's External environment often have
carbohydrates attached to them serve as identification badges that allow cells to
recognize each other and may act as Site where viruses or chemical messengers
such as hormones can attach.
1. Briefly describe the main functions of a cell membrane.
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2. Define the term selectively permeable.
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3. Concentration Gradients
a. The concentration of a solution is the ____________________
of solute in a given ____________________ of solution
b. Distinguish between active and passive transport
c. When does active transport occur?
Molecule to
be carried
Energy
Molecule
being carried
4. Define diffusion-
a.
b.
c.
5. When the concentration of the solute is the same throughout a
system, the system has reached ____________________.
During diffusion, substances will tend to move from an area of
____________________ concentration to an area of
____________________ concentration.
6. Define osmosis.
o
7. Is osmosis a form of active transport or passive transport?
Explain.
8. Describe the direction water will move in each of the following
cases.
A cell is placed in a hypertonic solution.
A cell is placed in an hypotonic solution.
A cell is placed in a Isotonic solution.
9. What is plasmolysis-
10. What are the two types of Bulk movement across cell
membranes? Do these require energy (active transport).
11. Describe what happens to large molecules, such as food
particles, during Endocytosis.
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12. What is the difference between Pinocytosis and Phagocytosis?
13. Describe what happens during exocytosis.
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