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Cell Structure
Review
Eukaryotic Cells
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Have a nucleus
Found in multi-cellular organisms
& some unicellular organisms
Prokaryotic Cells
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Do not have a nucleus
Found in bacteria
Cell Membrane
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Thin, flexible layer
Separates the cell from its surrounding
environment
Controls movement of materials into and out of
the cell
Helps maintain the cell’s internal environment
Cell Wall
Cell walls, found in plant cells, are
much stronger than cell membranes
 Rigid layer of non living material; made
of cellulose
 Helps protect and support
the cell

Nucleus
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Control center of the cell
Manages all of the cell’s
activities
Largest organelle
Contains the genetic
material (chromatin) the
cell needs to reproduce
and function.
Is surrounded by the
nuclear envelope and also
contains the nucleolus
Mitochondria

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Organelles that cause the release of energy by
using oxygen to break down sugars.
Releases food molecules that supply energy to
the cell; it is known as the powerhouse of the
cell.
Usually more than
one in a cell
Cytoplasm
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Thick, jelly-like
substance
contained within
the cell membrane
The majority of
the organelles are
suspended in the
cytoplasm.
Endoplasmic Reticulum
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Network of channels/tubes leading from the
nuclear membrane into the cytoplasm
Helps transport materials between the
nucleus and the cytoplasm; acts as an
assembly line
Also involved in transporting proteins
Two types:
- Smooth E.R. = no ribosomes
-Rough E.R. = contains ribosomes
Lysosomes

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Sac-like structures that
contain enzymes
Where digestion of cell
nutrients & food
molecules take place
Breaks down cellular
waste or things that are
harmful to the cell
• “clean up crew”
Centriole

Centrioles play an important role in
cell division. The centrioles are found
in pairs and move towards the poles
(opposite ends) of the nucleus when it
is time for cell division.
Chloroplast

Chloroplasts are organelles found only
in plant cells. Chloroplasts are the site
of photosynthesis, a process in which
the plant uses carbon dioxide, water
and sunlight to create energy in the
form of glucose for the plant.
Vacuole
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Think of these membrane sacs as
containment units. They can hold many
substances from organic molecules to
simple excess water. Plant cells have a
central vacuole that is important in
maintaining plant turgidity.
“Storage units”
Ribosomes
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Sites of protein
manufacturing in the cell
Assemble proteins that:
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Create chemical messages
to run a cell.
Build cell organelles
Line the membrane of the
rough endoplasmic
reticulum.
Golgi Bodies

Receive proteins and other newly
formed substances from the ER,
package them and distribute to other
parts of the cell
Labeling the cell parts

Please use page 22 of your Cells and
Heredity textbook to label the plant
and animal cell diagrams.