Transcript BC8_01_2 (1)

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
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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
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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
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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
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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
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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
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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
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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