Download The Cell

Introduction to Cells
Discovery of Cells
 The Cell - the basic unit of an organism
What piece of scientific equipment do you think
needed to be invented before this was
possible?…
The microscope!
The Cell Theory –
3 rules you must know
1. All organisms are composed of one or more cells.
2. The cell is the basic unit of structure and
organization of organisms.
3. All cells come from preexisting cells.
Viruses are NOT
considered living cells
Wacky History of Cell Theory
Overview of cell types
Prokaryotes
(no nucleus)
Eukaryotes
(have nucleus)
Plant
cell
Animal
cell
Prokaryotes
Eukaryotes
 Don’t have a nucleus
 Have a nucleus
 Don’t have organelles
 Have organelles
 Are very simple
 Are more advanced
 Oldest form of life
Ex: bacteria
Ex: plants, animals, fungi,
protists
Eukaryotes have Organelles
 Eukaryotic cells contain a variety of structures inside
them called ORGANELLES
 Special structures in a cell that each have their own
special job.
“Little
organs”
Organelles found in All
Eukaryotes
Eukaryotes
(have nucleus)
Plant
cell
Animal
cell
Nucleus
 Controls the cell’s life processes
 Stores genetic material (DNA)
 “Control Center” of the cell
Cytoplasm
 Where all the chemical reactions occur.
 A jelly-like substance that the organelles float in
Cell Membrane
(Plasma Membrane)
 Thin barrier that surrounds the cells
 Controls transport of materials in and out of the cell
 Waste exits cell through the membrane
Mitochondria
 “Powerhouse” of the cell
 Takes food and turns it into energy for the cell (Cellular
Respiration)
Vacuoles
 Stores food, waste, and water
 A “storage container” for the cell
Ribosome
 Makes proteins
 Proteins are needed for growth and repair of a cell
Lysosome
 Breaks down food and old cell parts.
Endoplasmic Reticulum
(ER)
 Makes fats and
proteins (in ribosome)
Golgi
 Packages and ships materials in
the cell
 “FedEx” of the cell
Centrioles
 Only found in animal cells and help with cell
reproduction
Organelles found only in Plants
•
Cell Wall – firm wall around cell that provides
support & protection
•
Chloroplast – use energy from the sun
to make food (photosynthesis)
Summary: Animal vs. Plant cell
Animal Cell
• Round shape
• Has centrioles
Plant Cell
• Square shape
• No centrioles
• Large vacuole in
center
• Has cell wall
See If You Can Answer These…
1. Which factor contributed most to the
development of the cell theory?
A) the discovery of many new species during
the last century
B) the development in advanced techniques to
determine the chemical composition of
substances
C) the increase in knowledge concerning
factors influencing the rate of evolution
D) the improvement in microscopes and
microscopic techniques during the last two
centuries
2. Which statement is not part of the cell theory?
A) Cells are the structural units in living things
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Which of the following describes a prokaryotic cell?
A) contain membrane bound organelles
B) do not have a nucleus
C) have a nucleus
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