Cell Organelles
Their Structures and Functions
Prokaryotic Bacteria Cell
Eukaryotic Plant Cell
Eukaryotic Animal Cell
Body Cell
Cell (Plasma) Membrane
• Structure - The lipid
bilayer that forms the
outer boundary of a cell
• Function(s) - Regulates
movement of molecules
into and out of cells;
semipermeable
• Found In - Bacteria,
Animal & Plant Cells
Cytosol
(Cytoplasm – the cytosol and all the
organelles within the cell)
• Structure - Gelatinous
aqueous fluid that fills the
cell
• Function(s)
- Suspends the organelles
within the cell
- Fills the cell and gives it
shape
- Allows nutrients to
move about the cell
• Found In - Bacteria,
Animal & Plant Cells
Nucleus
• Structure - The most
prominent organelle,
surrounded by a double
membrane perforated
with pores
• Function(s)
- Regulates all cell
activities
- Contains the DNA of
the cell
• Found In - Animal and
Plant Cells
Nucleolus
• Structure - Small
circular structure(s)
within nucleus
• Function(s) Synthesis and partial
assembly of ribosomes
• Found In - Animal
and Plant Cells
Nucleus & Nucleolus
Nuclear Envelope
• Structure - Double
membrane with pores
surrounding the nucleus
• Function(s) - Regulates
movement of molecules
into and out of the
nucleus
• Found In - Animal and
Plant Cells
Chromatin (DNA)
• Structure - Fine strands
of genetic information
(DNA and protein); coils
to form chromosomes
• Function(s)
- Contains the code that
directs most cell activities
- DNA’s code is the
instructions for making
proteins
• Found In - Bacteria,
Animal & Plant Cells
Mitochondria
• Structure - A peanutshaped organelle which
has a double membrane.
The inner membrane has
many folds.
• Function(s) – Performs
cellular respiration;
generates ATP (the energy
the cell needs to run)
• Found In - Animal and
Plant Cells
Mitochondria
Ribosomes
• Structure - Dot-like
organelles attached to the
rough ER or free in the
cytosol
• Function(s) – Reads RNA
to synthesize proteins
• Found In - Bacteria,
Animal & Plant Cells
Rough Endoplasmic Reticulum
• Structure – a system of
membranous tubes and
sacs covered with dark
dots (ribosomes)
• Function(s)
- Makes alterations to
proteins produced by
ribosomes
- Folds proteins into the
correct shapes
• Found In - Animal and
Plant Cells
Rough ER
Smooth Endoplasmic Reticulum
• Structure - A system of
membranous tubules and
sacs
• Function(s) - helps move
lipids, steroids, and fatty
acids within the cell
(intracellular highway);
regulates calcium levels;
breaks down toxic
substances
• Found In - Animal and
Plant Cells
Golgi Apparatus (Complex)
• Structure - A series of
flattened sacs with a
characteristic convex
shape
• Function(s) – Processes
and packages proteins
and substances produced
by cells; instructs the
substances where to go
• Found In - Animal and
Plant Cells
Lysosomes
• Structure - Small
spherical organelles that
enclose digesting enzymes
within single membranes
• Function(s) - Digests
molecules, old organelles,
and foreign substances;
recycling center
• Found In - Animal and
Plant Cells
Digesting enzymes
Cytoskeleton
(microtubules and microfilaments )
• Structure - A network
of long protein strands
located in the cytosol
• Function(s) - Provides
internal shape and
support to cells
(microfilaments and
microtubules)
• Found In - Animal
and Plant Cells
Flagella and Cilia
• Found In
- Bacteria and Animal
Cells
• Structure
- Flagella: Whip-like
tail(s) extending from the
surface of some cells
- Cilia: Short hair-like
organelles that extend
from the surface of some
cells
• Function(s)
- Propel the cell through
the environment
- Move materials over the
surface of the cell
Flagella (more than 1 flagellum)
Centrioles
• Structure - Cylindrical
bodies that appear during
cell division
• Function(s) – Help
move DNA during
division in animal cells
• Found In - Animal cells
only
Cell Wall
• Structure - A rigid
covering that lies outside
the cell membrane made
of long chains of
cellulose
• Function(s) - Provides
external protection and
support to plant cells
• Found In – Plants cells
only
(Bacteria can have a cell
wall but it is
biochemically different
from plant cell walls)
Vacuole
• Structure - Fluid filled
membranous sac
• Function(s) - Stores
enzymes and wastes;
cell’s warehouse
• Found In - Animal and
Plant Cells
(Can be very large in
plants cells, but small in
animal cells)
Plastid
• Structure - Organelles
surrounded by two
membranes and contain
their own DNA
• Function(s) - Stores food
or pigment
• Found In - Plant cells
only
Chloroplast
• Structure - Oval organelle
surrounded by a double
membrane that encloses a
system of flattened
membranous sacs
• Function(s) – Contains
chlorophyll and performs
photosynthesis; a type of
plastid.
• Found In - Plant cells only