Chapter 4
Cell Structure and Function
4.1 The Cell Theory
• Tenets of Modern Cell Theory
–Every living organism is made of
–The smallest living organisms are
_________ and _____ are the
functional units of multicellular
organisms
–All cells arise from______________
4.2. Basic Attributes of Cells
• Cell Size
– Most cells are
small, ranging from
_______
micrometers in
diameter. Some
are large
• Size/Functions:
– ____________
___________ with
the environment.
– No part of the cell
can be far away
from the external
environment
4.2. Basic Attributes of Cells
• Common Features:
• A ________
________________
encloses all cells
and regulates
material flow
4.2. Basic Attributes of Cells
• Common Features:
• ___________ is the
fluid interior where a
cell’s metabolic
reactions occur
– Contains _________
– Fluid portion
(_________)
contains ________
_________________
4.2. Basic Attributes of Cells
• Common Features:
• All cells use ___
_____________
____ as a hereditary
blueprint
• All cells use ___
_____________ to
copy DNA to make
proteins
4.2. Basic Attributes of Cells
• Common Features:
• All cells obtain
energy and nutrients
from _____
_____________
• All cells use
common _____
____________ to
build the molecules
of life
4.2. Basic Attributes of Cells
• There Are Two Basic Types of Cells:
____________________________
4.2. Basic Attributes of Cells
• Eukaryotic
– True nucleus
4.3. Major Features of
Eukaryotic Cells
4.3. Major Features of
Eukaryotic Cells
• Eukaryotic cells are >
• A variety of membraneenclosed ___________
perform specific functions
Cell Walls
• _______________
____________ of
bacteria, plants,
fungi, and some
protists
• Composed of
_______________:
– __________ (plants
and some protists)
– ______ (fungi)
• Function:
Cell Walls
• Cell walls in plants
may have multiple
layers
– _______________
in plants are
outermost
– ________________
are innermost
– Cell walls of
adjacent cells joined
by ______________
The Cytoskeleton
• Cytoskeleton forms a
network of _____________
within the cytoplasm
• Provides _____________
_______________
• Three types of proteins:
The Cytoskeleton
• Main functions of cytoskeleton
Cilia and Flagella
• Extensions of the ___________
________________
• Composed of _____________ in a
“9+2” arrangement formed by
_____________ which become
membrane-anchored structures
called _________________
• Long pairs of microtubules slide
along each other ___________
causing movement of cilia and
flagella
• Cilia are ______________ and
___________while flagella are
___________ but _____ in any cell
Cilia and Flagella
• Functions
– Cilia or flagella may be used _______________
– Cilia may be used to
The Nucleus
• • The nucleus is an organelle that contains
three major parts
The Nucleus
• -_____________
____________
separates
chromosomes from
cytoplasm
– Envelope is a _______
__________________
____ for transport.
Outer membrane is
studded with
The Nucleus
• The nucleus contains
DNA in various
configurations
– Compacted
________________
(during cell division)
– Diffuse __________
(as DNA directs
reactions through an
____ intermediate by
coding for ________)
The Nucleus
• Darker area within the nucleus
called the ______________
– Functions as the site of ________
_____________________
– Ribosomes synthesize
__________
• Ribosomes
– Small, roundish (not membrane)
structures made up by _______
__________________
• Made up of 2 subunits
• Some _______ in the cytoplasm
• Others
System of Membranes
• Membrane system includes the plasma
membrane and organelle membranes
System of Membranes
• Plasma membrane
• Plants, fungi, and some protists additionally
have a _________ outside the plasma
membrane
System of Membranes
• __________ are membranous sacs that
transport substances among the separate
regions of the membrane system
System of Membranes
• _______________________ forms a series
of enclosed, interconnected channels within
cell
• There are two forms of ER
––-
System of Membranes
• __________________ has no ribosomes
– Contains enzymes that ______________ (in
liver cells) or synthesizes _______________
System of Membranes
• __________________ is studded with
ribosomes on outside
– Produces _____________________________
_____________________________________
(export)
System of Membranes
• _______________ is a set
of stacked flattened sacs
– Receives proteins from ER
(via transport vesicles) and
sorts them by destination
_________________
– __________ some molecules
(e.g. proteins to
glycoproteins)
– _______________ into
vesicles for transport
(export). Many in secretory
cells
System of Membranes
•
Three fates of substances
made in the membrane
system:
1.
-
–
Figure 4-14 illustrates this
process for antibodies, proteins
produced by white blood cells to
inactivate foreign diseasecausing agents
System of Membranes
2. Digestive proteins (lysozyme)
made in RER, travel through
Golgi, and are packaged as –
• Lysosomes fuse with
food vacuoles and
digest food into basic
nutrients
• Destroy bacterial cells,
viruses, digestive worn out
organelles and whole cells
System of Membranes
3. Membrane proteins and lipids made in ER,
travel through Golgi, and …
Vacuoles Serve Many
Functions
• Fluid-filled sacs with a
______ membrane
• Functions of vacuoles
– ___________
vacuoles in freshwater
organisms used to
collect and pump water
out
Vacuoles Serve Many
Functions
• Functions of vacuoles
(continued)
– Plant _______________
used in several ways
• Maintain ..
• Store …
• Provide …___________
on cytoplasm to keep
cells rigid
Mitochondria Extract Food
Energy
• Mitochondrion (pl. -dria)
• _____________________
of the cell
• ___________, (or tubular
sacs of double-membranes)
• Outer membrane: ..
• Intermembrane compartment
• Inner membrane is folded into
…
• Internal matrix packed with
enzymes for ..
Mitochondria Extract Food
Energy
• Contains its own DNA
• Mitochondria may be remnants of free-living
prokaryotes (_______________________)
– (Lynn Margulis – Univ of MAs.):
– Eukaryotes evolved from two _________ in a
symbiotic relationship
• Internal prokaryotes became:
Mitochondria Extract Food
Energy
• Function as the “powerhouses of the cell”
Chloroplasts
• With double membrane
– __________ membrane
– __________ membrane encloses the ______ space
• Stacked hollow membranous sacs (
) within
stroma are called …
Chloroplasts
• Site of
Photosynthesis:
__________________
with pigments that
capture ___________
______________ and
make ________
– Chlorophylls a and b 
..
– Carotenoids alpha and
beta  ..
thylakoid
Plants Use Plastids for
Storage
• Plastids found only in
• Surrounded by a
double membrane
Plants Use Plastids for
Storage
• Functions
– _________ for
photosynthetic
products like
starch
– _________ of
pigment
molecules
giving color to
ripe fruit
4.4. Major Features of
Prokaryotic Cells
• Most prokaryotic cells (bacteria) …
• Shapes: ..
4.4. Major Features of
Prokaryotic Cells
• Specialized surface features
– Cell wall is usually present: of
– Infectious bacteria may have
polysaccharide adhesive
___________ and ______
__________ on their surfaces
– ________________. Protein
projections in some bacteria
that further enhance adhesion.
– Some bacteria are propelled
by _______________
4.4. Major Features of
Prokaryotic Cells
• Specialized structures
within their cytoplasm
(few)
– ..
– ..
– Small rings of DNA
(_______________)
chromosome
(nucleoid region)
pili
ribosomes
food granule
prokaryotic
flagellum
capsule or
slime layer
cell wall
plasmid (DNA)
cytoplasm
plasma membrane
Prokaryotic Cells
•
…Specialized structures
within their cytoplasm (few)
– ____nuclear membrane or
membrane-bound
organelles present
– Some have internal
membranes used to
___________________
– Cytoplasm may contain
_______________
Paramecium
cilia
cilia nucleus
mitochondrion
contractile
vacuole
Light microscope
50 micrometers
Transmission electron microscope
0.5 micrometers
mitochondria
Scanning electron microscope
10 micrometers
Scanning electron microscope
5 micrometers