C ELL S TRUCTURES &
O RGANELLES
C YTOPLASM
 Occurs inside the
plasma membrane
 Fluid portion of the
cell
C YTOSKELETON
Is a supporting
network of long,
thin protein
fibers that form a
framework for
the cell and
provide an
anchor for the
organelles inside
the cell
N UCLEUS

Isolated region where the DNA is

Double membrane allowing for
DNA to carry out its functions and
not be affected by processes
occurring in other parts of the
cell

Without a nucleus, a cell cannot
reproduce. Loss of reproductive
ability is often paired
w/increased specialization

Human red blood cells do not
have a nuclei; they are
specialized to transport oxygen
R IBOSOMES

Structures found free in the cytoplasm
or attached to the ER

Always composed of a type of RNA
and protein

Carry out protein synthesis
E NDOPLASMIC R ETICULUM

Extensive network of tubules or
channels that extends almost
everywhere in the cell

Transportation of material throughout
the internal region of the cell

Two kinds of ER: Smooth & Rough
S MOOTH ER
Has unique enzymes
embedded
Production of membrane
phospholipids and cellular
lipids
Production of sex
hormones (testosterone
& estrogen)
R OUGH ER

Has ribosomes on the exterior of the
channels

Protein synthesis– protein development and
transport

Proteins might become parts of membranes,
enzymes, or even messenger cells
G OLGI A PPARATUS

Appears to be flattened sacs called cisternae,
which are stacked on top of one another

Function in the collection, packaging,
modification, and distribution of materials
synthesized in the cell
VACUOLES

Occupy a very large space in the cell

Provide storage (food, wastes, water)

Vacuoles enable cells to have higher
surface area to volume rations

Uptake of water in plants that
provide rigidity for the organism
LYSOSOMES

Intracellular digestive centers that arise from the
Golgi apparatus

Sacs bounded by a single membrane that contain
as many as 40 different enzymes

Enzymes also digest bacteria and viruses that
have entered the cell

Lysosomes also bond with older or damaged
organelles from with and help recycle them
C ENTRIOLES
Are organelles
made of
microtubules that
function during cell
division
Located in the
cytoplasm of
animal cells near
the nucleus
M ITOCHONDRIA
Rod-shaped
organelles that
appear throughout
the cytoplasm
Involve the
production or
usable cellular
energy called ATP
“cell powerhouse”
C HLOROPLASTS

occur only in algae and plant cells

Capture light energy and convert
it to chemical energy through a
process called photosynthesis

Also contains grana, thylakoids, and
stroma

Thylakoids are flattened membrane
sacs w/ components necessary for the
absorption of light
C ELL WALL

Only found in plant cells

The cell wall is a thick, rigid, mesh of
fibers that surrounds the outside of
the cell membrane

Provides protection and support
C ILIA AND
FLAGELLA

Cilia are short, numerous projections
that look like hair

Flagella are longer and less numerous

Both are used for locomotion
(movement)
P LANT
VS .
A NIMAL
Plant Cells
Animal Cells
Nucleus present
Nucleus present
Cell wall present
Cell wall missing
chloroplasts
Chloroplasts
missing