Chapter 7 Cellular Structure and Function
Section 1: Cell Discovery and Theory
Section 2: The Plasma Membrane
Section 3: Structures and Organelles
S ti 4:
Section
4 Cellular
C ll l T
Transportt
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Chapter 7
Cellular Structure and Function
7.1 Cell Discovery and Theory
The Cell Theory
 All organisms are composed of one or
more cells.
 The cell is the basic unit of structure and
organization of organisms.
 All cells come from preexisting cells.
Chapter 7
Cellular Structure and Function
7.1 Cell Discovery and Theory
Light Microscopes
 Utilizes a series of
glass lenses and
visible light to
magnify an image
 Magnifies images
up to 1,000 times
the actual size
1
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.1 Cell Discovery and Theory
7.1 Cell Discovery and Theory
Electron Microscopes
Prokaryotic Cell
 Utilizes magnets to aim a beam of electrons at
a cell to produce
an image
 Simple structure
 Magnifies
images up to
500,000 times
the actual size
 Contains a plasma
membrane
 Does not contain
membrane-bound
organelles
11,000x
9560x
Microscopy Links http://biologygmh.com/
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.1 Cell Discovery and Theory
7.2 The Plasma Membrane
Eukaryotic Cell
Plasma Membrane
 Thin, flexible boundary between the cell
and its environment
 Allows nutrients into the cell
 Allows
All
waste
t to
t leave
l
the
th cellll
 More complex
structure
 Co
Contains
ta s a p
plasma
as a
membrane
 Contains membranebound organelles
400x
2
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.2 The Plasma Membrane
7.2 The Plasma Membrane
Selective Permeability
 The plasma membrane is composed of the
phospholipid bilayer.
 A phospholipid molecule is composed of a glycerol
backbone, two fatty acid chains, and a phosphate
group.
 The plasma membrane controls the movement of
substances into
and out of the cell.
Pl
Plasma
M
Membrane
b
 Controls the amount of a
substance entering the cell
 Controls the amount of a
substance leaving the cell
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.2 The Plasma Membrane
7.2 The Plasma Membrane
Fluid Mosaic Model
 The phospholipid
bilayer allows other
molecules to “float”
in the membrane.
membrane
Proteins
 Transmit signals inside the cell
 Act as a support structure
 Provide pathways for substances to enter and leave
Other Components
 Proteins
 Cholesterol
 Carbohydrates
3
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.2 The Plasma Membrane
7.2 The Plasma Membrane
Cholesterol
Carbohydrates
 Prevents fatty acid tails from sticking together
 Identify chemical signals
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.3 Structures and Organelles
Plant and Animal Cell Structures
Animal Cell
Plant Cell
Cellular Pursuit
4
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.3 Structures and Organelles
Chapter 7
Cellular Structure and Function
7.3 Structures and Organelles
Chapter 7
Cellular Structure and Function
7.3 Structures and Organelles
5
Chapter 7
Cellular Structure and Function
Cellular Structure and Function
7.3 Structures and Organelles
400x
26,367x
Chapter 7
Cellular Structure and Function
http://biology.clc.uc.edu/course
s/b o 0 /ce s t
s/bio104/cells.htm
6
Cellular Structure and Function
•One or more per cell
•Spherical shape
•Collective term for cytosol and organelles
contained within
•Colloidal suspension
•Cytosol mainly composed of water with
free-floating molecules
Nucleolus
Chromatin
- Contains genetic information
- Composed of DNA
- Forms chromosomes
Nuclear membrane
- Surrounds nucleus
- Composed of two layers
- Numerous openings for nuclear traffic
- Spherical shape
- Visible when cell is not dividing
- produces ribosomes
Centrioles
- Paired cylindrical organelles near nucleus
- Involved in cellular division
- Lie at right angles to each other
7
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Chloroplasts
Passive Transport
- A plastid usually found in plant cells
- Contain green chlorophyll where
photosynthesis takes place
 Movement of particles across the cell
membrane without using energy
Th
Three
M d off P
Modes
Passive
i T
Transportt
Cytoskeleton
 Diffusion
 Facilitated Diffusion
 Osmosis
- Composed of microtubules
- Supports cell and provides shape
- Aids movement of materials in and out of
cells
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
7.4 Cellular Transport
Diffusion
 Diffusion is controlled by
 Movement of particles from an area of high
concentration to an area of lower concentration
Initial Conditions
Diffusion
Low
High
 Temperature
 Pressure
 Concentration
High
Dynamic Equilibrium
Low
 Reached when diffusion of material into the
cell equals diffusion of material out of the cell
 Molecules continue to move, but the overall
concentration remains the same.
8
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
7.4 Cellular Transport
Diffusion in a Cell
Facilitated Diffusion
 Movement of materials across the plasma
membrane using proteins
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Channel Proteins
Carrier Proteins
9
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Osmosis
 Diffusion of water across a selectively
permeable membrane
Three Types of Solutions
 Isotonic
 Hypotonic
 Hypertonic
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
7.4 Cellular Transport
Isotonic Solution
 Water and dissolved substances diffuse into
and out of the cell at the same rate.
Hypotonic Solution
 Solute concentration is higher inside the cell.
 Water diffuses into the cell.
Plant Cell
Blood Cell
11,397x
Plant Cell
Blood Cell
13,000x
10
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
7.4 Cellular Transport
Hypertonic Solution
Active Transport
 Solute concentration is higher outside the cell.
 Movement of particles across the cell
membrane using energy
 Water diffuses out of the cell.
Plant Cell
Blood Cell
13,000x
Chapter 7
Cellular Structure and Function
Active Transport Using Carrier Proteins
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Types of Active Transport Pumps
 Na+/K+ ATPase pump
 Moves three Na+ ions out of the cell and
ttwo
o K+ ions
o s into
to tthe
e ce
cell
11
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Endocytosis
 Process by which the
cell surrounds and takes
particles into the cell
Exocytosis
 Secretion of material out
of the plasma membrane
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