Chapter 3
3.1 Cell Theory
3.2 Organelles
3.3 Cell membrane
3.4 Passive transport
3.5 Active transport
3.1 Cell Theory
Describe the scientific theory of cells (cell theory) and
relate the history of its discovery to the process of
science.
Cell Theory
Early studies led to the
development of the cell
theory.
A. The cell theory grew out
of the work of many
scientists and
improvements in the
microscope
1.
2.
3.
4.
5.
Hooke
Leeuwenhoek
Schleiden
Schwann
Virchow
Cell Theory
B. More was learned about
cells as microscopes
improved
C. The cell theory is a
unifying concept of
biology
Cell Theory
D. The cell theory has three
principles
1.
2.
3.
All organisms are made
of cells
All existing cells are
produced by living cells
The cell is the most
basic unit of life
Cell Theory
Prokaryotic cells lack a
nucleus and most internal
structures of eukaryotic
cells
A. All cells share certain
cell membrane
characteristics
1.
2.
3.
cytoplasm
Cells tend to be
microscopic
All cells are enclosed by
a membrane
All cells are filled with
cytoplasm
Cell Theory
B. There are two types:
nucleus
organelles
Eukaryotic cells and
Prokaryotic cells
1.
2.
cell membrane
Eukaryotic cells have a
nucleus and membrane
bound organelles
Prokaryotic cells do not
have a nucleus or
membrane bound
organelles
Cell Theory
Write summary
3.2 Cell Organelles
Compare and contrast the general structures of plant
and animal cells. Compare and contrast the general
structures of prokaryotic and eukaryotic cells.
Cell Organelles
Cells have an internal
structure
A. The cytoskeleton has
many functions
1.
2.
3.
4.
5.
Supports and shapes cell
Helps position and
transport organelles
Provides strength
Assists in cell division
Aids in cell movement
Cell Organelles
Several organelles are
involved in making and
processing proteins
A. The nucleus stores genetic
information
B. Many processes occur in
the endoplasmic
reticulum
1.
2.
Production of proteins
and lipids
There are two types
a.
Rough
b. Smooth
Cell Organelles
C. Ribosomes link amino
acids to form proteins
1.
Ribosomes are found on
the Rough ER and in
the cytoplasm
D. Golgi Apparatus sorts and
delivers proteins. Also
packages proteins.
E.
Vesicles store and
transport material
through the cell.
Cell Organelles
Other organelles have
various functions
A. Mitochondria supplies
energy to the cell
B. Vacuoles are fluid filled
sacs that hold material
1.
Central vacuole is a
large vacuole that is
found in plant cells.
C. Lysosomes contain
enzymes to digest material
D. Centrioles are tubes
found in the centrosomes
A.
B.
Help divide DNA
Form cilia and flagella
Cell Organelles
Plant cells have cell walls
and chloroplast
A. Cell wall provides rigid
support to plant cells
B. Chloroplasts convert solar
energy to chemical energy
Cell Organelles
Write summary
3.3 Cell Membrane
Relate structure to function for the components of
plant and animal cells. Explain the role of cell
membranes as a highly selective barrier (passive and
active transport)
Cell Membrane
Cell membranes are
composed of two
phospholipid layers
A. The cell membrane has
two major functions
1.
2.
Forms a boundary
between inside and
outside of the cell
Controls passage of
materials
Cell Membrane
B.
The cell membrane is made
of phospholipid bilayer (2
layers of phospholipids)
C.
There are other molecules
embedded in the membrane
1.
D.
This is called the fluid
mosaic model
Is selectively permeable
1.
Only certain molecules
can enter and exit the cell
Cell Membrane
Chemical signals are
transmitted across the cell
membrane
A. Receptors are proteins
that bind with ligands
(molecules that send
signals) and change shape
B. There are two types of
receptors
1.
2.
Intracellular receptor is
inside the cell
Membrane receptor is
inside the membrane
Cell Membrane
Write summary
3.4 Diffusion and Osmosis
Relate structure and function for the components of
plant and animal cells. Explain the role of cell
membranes as a highly selective barrier (passive and
active transport).
Diffusion and Osmosis
Diffusion and osmosis are
types of passive transport
A. Passive transport does not
require energy and is the
movement of molecules
down a concentration
gradient
1.
There are two types of
passive transport
a.
Diffusion: movement
of molecules
b. Osmosis: movement of
water
Diffusion and Osmosis
**** note to students****
Write down the
definitions with this slide
from the pictures
B. There are three types of
solutions
1.
2.
3.
Isotonic
Hypertonic
Hypotonic
Diffusion and Osmosis
Some molecules diffuse
through transport
proteins
A. Some molecules cannot
easily diffuse across the
cell membrane
B. Facilitated diffusion is
diffusion through
transport proteins
Diffusion and Osmosis
Write summary
3.5 Active Transport,
Endocytosis, Exocytosis
Relate structure and function for the components of
plant and animal cells. Explain the role of cell
membranes as a highly selective barrier (passive and
active transport).
Active Transport, Endocytosis,
Exocytosis
Proteins can transport
materials against a
concentration gradient
A. Active transport requires
energy input from a cell
and enables a cell to move
a substance against its
concentration gradient
1.
2.
Powered by chemical
energy (ATP)
Cells use active
transport to maintain
homeostasis
Active Transport, Endocytosis,
Exocytosis
Endocytosis and
exocytosis transport
materials across the
membrane in vesicles
A. Endocytosis
1. A cell can import large
materials through the
use of vesicles
a.
Phagocytosis is another
name meaning “cell
eating”
B. Exocytosis
1. The opposite of
endocytosis where large
materials are exported
from the cell using
vesicles
Active Transport, Endocytosis,
Exocytosis
Write summary