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1.2 Cells
• An analogy is a way to understand new ideas by
making a comparison.
• A factory can be used as an analogy for the cell.
• Parts of the cell that allow the cell to survive are called
organelles.
• Organelles take up about 5 to 30 percent of the cell.
The rest of the cell consists of water.
How is the Newo colony similar to
a factory?
See pages 22 - 24
(c) McGraw Hill Ryerson 2007
The Functions of Cell Organelles
• The cell membrane protects the cell and regulates the movement
of particles in and out of the cell.
• Cytoplasm, the jelly-like substance within the cell, contains
organelles, water, and other life supporting materials.
• The nucleus:
 controls all the activities within the cell.
 contains deoxyribonucleic acid (DNA).
See page 25
(c) McGraw Hill Ryerson 2007
Energy in the Cell
• The mitochondria are the organelles that produce
energy in the cell.
• When the cell changes chemical energy, in the food we
eat, to energy the cell can use, it is called cellular
respiration.
• The total of all the chemical reactions that take place
in our cells is called our metabolism.
See page 26
Cellular Respiration
(c) McGraw Hill Ryerson 2007
Organelles for Assembly, Transport, and Storage
• Proteins are essential for all life
and are assembled by the
ribosomes.
• Proteins then pass through the
endoplasmic reticulum and are
placed in vesicles by the Golgi
body.
• Vacuoles are temporary storage
compartments.
• Lysosomes break down food
particles, cell wastes, and wornout organelles.
See pages 28-29
(c) McGraw Hill Ryerson 2007
The Difference Between Plant and Animal Cells
• Plant cells have two parts that are not
found in animal cells:
 Cell Wall
 protects the cell and gives cell shape
 Chloroplasts
 change the Sun’s energy into chemical
energy
Locate the cell wall and
chloroplast
See pages 29-30
Photosynthesis
(c) McGraw Hill Ryerson 2007
Cell Theory
• The cell is the basic unit of life.
• All organisms are composed of one or more cells.
• All cells come from other living cells.
See pages 31-32
(c) McGraw Hill Ryerson 2007
Prokaryotic and Eukaryotic Cells
Cells are classified into two groups:
Prokaryotic cells have
organelles that are not
surrounded by membranes.
Eukaryotic cells have
organelles that are
surrounded by
membranes.
Eukaryotic cells are
usually larger than
prokaryotic cells.
See page 32
(c) McGraw Hill Ryerson 2007
Bacteria and Viruses
Bacteria are prokaryotic cells.
• Some bacteria cause diseases such as:
tuberculosis and strip throat.
• Helpful bacteria are used to make food
such as: cheese and yogurt.
• Bacteria are often grouped by the shape of
their cells.
Viruses are not living.
• HIV, chicken pox, and the flu are examples
of viruses.
• Viruses do not contain any cell organelles
but reproduce by using a host cell.
See pages 33 - 34
Take the Section 1.2 Quiz
(c) McGraw Hill Ryerson 2007