Plant and Animal Cells
Discovery of the Cell
Early microscope was invented in the mid-1600s.
Robert Hooke first saw cells in 1663.
He called the tiny units he saw under the microscope
“cells” because they resembled the cells of
honeycombs in a bee hive.
What is a CELL?
Not all cells are the same but all cells share certain
traits and structures.
Cell theory states that:
●
Cells are the basic unit of
life.
●
All living things are made of
cells.
●
All cells come from preexisting cells.
Cells Parts and Their Functions
Our bodies are made up of between 10 trillion and
100 trillion cells.
The smaller parts that make up cells are called
organelles. By themselves organelles are not
considered alive but together with all the other
organelles they form a cell; a living unit.
Different organelles have different structures and
functions.
The Purpose of Organelles
Organelles maintain the life processes of the cell,
including:
● Intake of nutrients
● Movement
● Growth
● Response to stimuli
● Exchange of gases
● Waste removal
● Reproduction
The Organelles - Cell Membrane
● Forms the protective barrier around the cell. It is
made of a double layer of lipids (fats). Cell
membranes are designed to allow different
substances to move through them.
The Organelles - Cell Membrane
● Diffusion is one way of moving substances
across the membrane. It does not require
energy. The substance simply moves from the
side of the membrane with the higher
concentration of the substance to the side with
the lower concentration of the substance.
The Organelles - Cytoplasm
● This is a jelly-like
substance that fills the
cell. All other
organelles are
suspended in the
cytoplasm. It contains
the nutrients required
by the cell.
The Organelles - Nucleus
● This is the “brain”/control centre of the cell. It
controls all activities within the cell.
● The nucleus is surrounded by its own membrane
called the nuclear envelope.
● Most nucleii contain a dense centre called the
nucleolus.
● Contains the DNA (deoxyribonucleic acid), which
is the blueprint for the cell. DNA is coded
information for making proteins and molecules.
The Organelles – Vacuoles and
Vesicles
● Membrane-bound organelles
that store and transport
nutrients, wastes, and other
substances in the cell.
● Plant cells have one VERY
large central vacuole that
stores water and provides
rigidity to the plant.
The Organelles - Mitochondria
● The “Powerplant” of the cell.
● Chemical energy in sugar is
converted to useable energy
in the mitochondria by a
chemical reaction called
cellular respiration.
The Organelles - Lysosomes
● Small organelles filled with
enzymes.
● They break down invading
bacteria and damaged parts of
the cell.
● They are the “cleaners” of the
cell
This is a joke.
The Organelles – Endoplasmic
Reticulum (ER)
The “highway” of the cell. It is
made of a series of tubes that
carry materials through the cell.
Extra Info
2 kinds:
● Rough ER (rER) → covered in
ribosomes and used for
making proteins. Ribosomes
are where proteins are
assembled.
● Smooth ER (sER) → has no
ribosomes. Used in the
production of fats and oils.
The Organelles - Cytoskeleton
● An internal network of fibres
made of proteins filaments.
● It helps maintain the cell’s
shape.
Plant vs Animal organelles
Plant cells have some organelles that animal cells do
not. They are the cell wall and chloroplasts.
Animal cells
have
centrioles
(used in cell
division)
which plant
cells do not.
Plant-specific Organelles – Cell
Wall
● Plants, bacteria, fungi and some algae have cell
walls.
● It is a rigid frame that wrap around the cell
membrane and helps to provide strength,
protection and support. Remember these things
don’t have bones like animals do.
Plant-specific Organelles Chloroplasts
● Found only in plant cells and some algae.
● Contain a green pigment called chlorophyll.
● Chlorophyll converts energy from the sun into
usable chemical energy in the form of sugar.
SUMMARY - Differences between
plant and animal cells
● Plants have cells walls and chloroplasts
● Plants have chlorophyll, used for photosynthesis.
● Plants have a large central vacuole used for support.
● Plant cells store energy as starch or oils while animal
cells store energy as glycogen, carbohydrates or
lipids in the form of fats.
● Some animal cells have specialized compounds like
hemoglobin.
● Animal cells have centrioles, which are used in cell
division.
What we’re working on
Pg 16 #1-5
Pg 25 #1-5