Cell Structure &
Function
Sections 7-2 and 7-3
Eukaryote vs. Prokaryote
eukaryotes:
organisms
whose cells contain a nucleus
prokaryotes: organisms
whose cells lack a nucleus
a
tiny
area between
structure that
the nucleus
performs a
and the cell
specialized
membrane
function in the where the
cell
organelles are
found
yes
no
yes
yes
yes
yes
yes
no
both
unicellular
plants,
animals,
fungi,
protists
bacteria
A. Boundary Structures
Cell
Wall
Location:
outside the cell
membrane
Function: helps to protect
& support the cell
A. Boundary Structures
Cell
Wall
found
in cells of
plants, algae, and
some bacteria
made of cellulose
and lignin
A. Boundary Structures
Cell Membrane
Function: regulates what
enters and leaves the cell.
Also aids in protection and
support of the cell.
Made of lipids with associated
proteins and carbohydrates.
Structure of the Cell
Membrane
B. Nucleus
organelle
that controls the cell’s
activities and contains DNA
Nuclear envelope
(membrane): two membranes
that form the boundary around
the nucleus
B. Nucleus
Nucleolus:
 where ribosomes are made
 made of RNA and proteins
 Chromatin:
 DNA bound to protein
 Spread throughout the nucleus
 Chromosomes:
 Distinct structures in nucleus that contain
the genetic info that must be passed to
each new generation of cells

C. Energy Producing Organelles
change
the chemical energy
stored in food into compounds
that are more convenient for the
cell to use
have a degree of
independence from the rest
of the cell
C. Energy Producing Organelles
trap
sunlight
the energy of
and
convert it into chemical energy
found only in plant cells &
algae
have a degree of independence
from the rest of the cell
D. Transport/Homeostasis
Ribosomes
structures
in which proteins
are made
composed of RNA & protein
some are attached to
membranes (rough ER);
others are free in the
cytoplasm
D. Transport/Homeostasis
Endoplasmic
Reticulum
(er)
complex
network of sacs that
transport materials in the cell
2 types:
smooth er
rough er

D. Transport/Homeostasis
Smooth
walls
er
of the sacs look smooth
stores special chemicals and
enzymes
D. Transport/Homeostasis
Rough
er
involved
in synthesis of
proteins
has ribosomes stuck to
surface (make it look “rough”)
chemically modifies proteins
D. Transport/Homeostasis
Golgi
looks
apparatus (body)
like a flattened stack of
membranes (pancakes)
modifies, collects, packages,
& distributes molecules made
at one location of the cell and
used at another
Golgi apparatus
D. Transport/Homeostasis
Lysosomes
contain
chemicals & enzymes
necessary for digesting certain
materials in the cell
the
“clean-up crew”
not
in plant cells
D. Transport/Homeostasis
Vacuoles
saclike
storage structures
store water, salts, proteins,
and carbohydrates
plants have a large central
vacuole to store excess water
D. Transport/Homeostasis
Plastids
store
food and pigments
3 examples
chloroplasts: store
chlorophyll
leukoplasts: store starch
chromoplasts: store pigment
molecules
E. Framework
Cytoskeleton
of filaments and
fibers that support cell
structure and drive cell
movement
composed of microtubules and
microfilaments
variety
Cytoskeleton
E. Framework
Microtubules
 hollow
tubes
 aid in support and movement
Cilia: short, thread-like
 Flagella: long, whip-like

 Centrioles
Located near the nucleus
 Help organize cell division
 Not found in plant cells

E. Framework
Microfilaments
long,
thin fibers
movement & support
movement of cytoplasm