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It’s All About Cells!
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In 1665, Robert Hook,
an English scientist,
experimented with a
simple microscope.
Can you see cells?

He observed tiny,
orderly, but empty
spaces in a thin slice
of cork, a type of
dead plant material.
He called these
spaces cells.
CELLS
Cells are the BASIC units
of ALL LIVING
organisms.
The Cell Theory



ALL living things are made up of CELLS.
The CELL is the BASIC unit of ALL living things.
Only LIVING cells can produce LIVING CELLS.
The structure of cells

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Cells come in many SHAPES and SIZES.
Some cells are very SIMPLE in their STRUCTURE.
Other cells, however, do contain many SPECIALIZED
structures that perform the various functions of cell
activity.
TYPES OF CELLS:

PLANT, ANIMAL,
BLOOD, SKIN, ETC.
BASIC PARTS OF ALL CELLS
PLANT & ANIMAL
CELL MEMBRANE
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SURROUNDING each cell is a COVERING called the
cell membrane.
This is the part of the cell that determines what ENTERS and
LEAVES the cell.
CYTOPOLASM

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All cells have a
JELLY-LIKE
substance called
cytoplasm.
Many of the
ACTIVITIES of a
CELL are CARRIED
out here.
NUCLEUS

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Near the CENTER of
most cells is a
structure called the
nucleus.
It is the “CONTROL
CENTER” of the
CELL that directs all
of the CELL’S
activities.
 It
is surrounded by a
MEMBRANE called the
NUCLEAR MEMBRANE.
Contained in the nucleus are the
genetic materials DNA and RNA.

DNA

RNA
DNA stands for
DEOXYRIBONUCLEIC
ACID.

These complex organic molecules contain, TRANSPORT, and
INTERPRET the instructions for the REPRODUCTION,
growth, and DEVELOPMENT of all LIVING organisms.
Throughout the nucleus are
structures called CHROMOSOMES.
They are ROD- shaped structures
that are made of coiled DNA.
All human
cells have
46
chromosomes.
OGANELLES
TINY specialized structures within
a CELL that PERFORM cell
functions.
Organelles means “LITTLE ORGANS”
VACUOLES
 STORAGE
areas
located in
the
CYTOPLASM
 Some
of these vacuoles store
FOOD for future use. Some
store CHEMICALS. Others
store WASTES until they can be
removed from the cell.

In animal cells
they resemble
TINY AIR
BUBBLES.

In plants they
are much
larger.
MITOCHONDRIA
Structures in the
CYTOPLASM that
release ENERGY
and FOOD.

These are also
called the POWER
GENERATORS or the
“power house” of
the cell.

They produce energy for cell activities by
CELLULAR RESPIRATION, a process that is
similar to burning.
RIBOSOMES
 Structures
in the CYTOPLASM
where PROTEINS are made.

They are TINY,
round structures
that are attached
to a LONG,
WINDING
NETWORK in the
cytoplasm called
the endoplasmic
reticulum.
UNIQUENESS OF PLANT CELLS

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Plant cells contain all the structures that
are found in animal cells.
But there are several (mainly 3)
differences that are unique to plant
cells.
Size of Vacuole

Vacuoles in plant cells are very
large.

Like the vacuoles in animal cells,
the plant cell vacuole also acts
as a storage area.

It’s also filled
with a clear fluid
that is mostly
water, but also
contains some
sugar, starch,
and protein
molecules.
CELL WALL

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Plant cells also have a THICK, FIRM, outer boundary called a
cell wall.
It is a rigid, protective structure that SURROUNDS the plant
cell.
The cell wall SUPPORTS and PROTECTS the cell.
Animal cells DO NOT have a cell wall, just a CELL
MEMBRANE.
Ability to Make Its Own Food

In the CYTOPLASM of some plant cells, there are many SMALL,
GREEN structures called CHLOROPLASTS.

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These OVAL-shaped
structures in plant
cells contain
CHLOROPHYLL.
Chlorophyll is organic
MATERIAL in green
plants that ABSORBS
sunlight for MAKING
FOOD.

Chlorophyll enables a plant cell to make its own food
by a process called PHOTOSYNTHESIS.