Goal 2.02:
Cell Structure and Functions
Discovery Lab: Light Microscopes, Cells and Magnification
http://www.simpletruths.tv/store/movies.php?movie=tssc
AP Biology
2008-2009
Types of Cells
bacteria
cells
Prokaryote
- no organelles
animal cells
plant cells
Eukaryotes - Have membrane bound organelles
What differences can you see between these cells?
Cell size comparison
most bacteria
Animal cell
Bacterial cell
 1-10 microns
eukaryotic cells
 10-100 microns
Viruses are smaller
than bacteria and
they are NOT ALIVE!
 micron = micrometer = 1/1,000,000 meter
 diameter of human hair = ~20 microns
The Cell Theory
1. All living things are made of cells.
2. New cells come from cells.
3. Cells are the basic units of structure and function
of living things.
May the CODE be with you!
1. ALTMC
2. NCFC
3. CBUSFLT
Cell Quiz 01
1. What type of cell is shown below? (Plant or Animal)
Cell Quiz 01
2. What type of cell is shown below?
(Eukaryote or Prokaryote)
Cell Quiz 01
3. What type of cell is shown below?
(Plant, Animal or Bacteria)
Cell Quiz 01
Write out the Three Points of the Cell Theory.
4. _____________________________________________
5. _____________________________________________
6. _____________________________________________
Cell Quiz 01
7. What part of the cell theory provides evidence to
the concept of Unity among living things?
8. What part of the cell theory provides a mechanism
for the evolution of organisms?
9. What part of the cell theory supports the concept of
the organization of all living things?
10. List the following from largest to smallest:
prokaryotic cell, virus, eukaryotic cell
Organelles = membrane bound
structures inside a cell that perform
specific functions required by the
cell.
Model Animal Cell
Cell MEMBRANE
 Structure
phosphate
“head”
double layer of fat
 phospholipid bilayer
 Proteins

 receptor molecules
 transport molecules
lipid “tail”
Cell MEMBRANE (cont.)
FUNCTIONS of the Cell Membrane:
1. Separates the inside of the cell from the outside environment.
2. Transport proteins control what enters and leaves the cell.
3. Receptor proteins communicate between cells and with
anything in the environment.
Cell Communication
Some cells can send signals to other cells.
Ex. Nerve cells sending chemical signals, called
impulses to other nerve cells. This is how your brain tells
your finger that it has touched a hot stove!
Ex. Plant hormones stimulate the growth and death of
plant cells.
Auxin: responsible for the growth
pattern of plants toward sunlight
Gibberellins tell the plant embryo to
cease being dormant and germinate.
Cytokinins promote cell division and
differentiation.
Cytoplasm = jelly-like filling that holds organelles
Centrioles = used in cell division and replication
Surface Area: Volume Lab
http://www.biologyjunction.com/cell_size.htm
Vacuoles & Vesicles
food vacuoles
central vacuole
animal cells
plant cells
contractile
vacuoles
 Structure
Lysosomes

membrane sac of
digestive enzymes
 Function

small food
particle

digest food
clean up & recycle
 digest broken
lysosomes
vacuole
digesting food
organelles
digesting broken
organelles
Mitochondria
 Structure

double membrane
 Function
make ATP energy
 cellular respiration

 sugar + O2  ATP
 fuels the work of life
ATP
Plants make energy two ways!
 Mitochondria

make energy from sugar + O2
 cellular respiration
 sugar + O2  ATP
ATP
 Chloroplasts

make energy + sugar from sunlight
 photosynthesis
 sunlight + CO2  ATP & sugar
 ATP = active energy
 sugar = stored energy

build leaves & roots & fruit
out of the sugars
ATP
sugar
Mitochondria are in both cells!
Chloroplasts are only in plant cells.
animal cells
plant cells
mitochondria
Chloroplast/plastid
When things go bad…
 Diseases of lysosomes are fatal
digestive enzyme not working in lysosome
 picks up food, but can’t digest it

 lysosomes fill up with undigested material

grow larger & larger until disrupts cell &
organ function
 example:
Tay-Sachs disease
build up undigested fat
in brain cells
Tay Sachs Disease
http://www.teachersdomain.org/resource/tdc02.sci.life.gen.onewrong/
But sometimes cells need to die…
 Lysosomes can be used to kill cells when
they are supposed to be destroyed
some cells need to die as a part of normal
development in an organism
 “auto-destruct” process

 lysosomes break open and kill cell
 cell “suicide”
Example 1 of necessary Lysosome work:
Tadpoles must re-absorb their tails when becoming a frog.
Example 2 of necessary Lysosome work:
During human fetal development cells must be destroyed to
separate fingers and toes.
6 weeks
syndactyly
15 weeks
Where is the nucleus in a bacterial cell?
Nucleus
 Function
control center of cell
 protects DNA

 instructions for building proteins
 Structure
nuclear membrane
 nucleolus

 ribosome factory

chromosomes
 DNA
Ribosomes
 Function


protein factories
read instructions to build proteins from DNA
 Structure



2 subunits
some free in cytoplasm
some attached to ER Ribosomes on ER
large
subunit
small
subunit
Endoplasmic Reticulum
 Function

part of protein factory
 helps complete the
proteins

makes membranes
 Structure

rough ER
 ribosomes attached
 works on proteins

smooth ER
 makes membranes
cytoplasm
jelly-like material holding
organelles in place
vacuole & vesicles
transport inside cells
storage
lysosome
food digestion
garbage disposal &
recycling
ribosomes
builds proteins
mitochondria
make ATP energy
from sugar + O2
cell membrane
cell boundary
controls movement
of materials in & out
recognizes signals
nucleus
protects DNA
controls cell
ER
helps finish proteins
makes membranes
Golgi Apparatus
 Function

finishes, sorts, labels & ships proteins
 like UPS headquarters
 shipping & receiving department

ships proteins in vesicles
 “UPS trucks”
 Structure

vesicles
carrying proteins
membrane sacs
transport vesicles
endoplasmic
reticulum
nucleus
protein
on its way!
DNA
RNA
vesicle
TO:
TO:
TO:
vesicle
ribosomes
TO:
finished
protein
protein
Golgi
apparatus
Making Proteins
Animal Cell
Plant Cell
Cell Specialization
In unicellular organisms, cells are not specialized. One cells does all.
In multicellular organisms, cells become specialized with different
types of cells performing different functions for the organism.
You can dissolve an embryonic heart into
its individual cell types with trypsin, an
enzyme that destroys the protein glue
between the cells. Plate these cells in a
dish and you will see some cells - called
myocytes - that beat independently.
A single cell beats when a complex series
of gates – called ion channels - open and
close in an organized manner. The cells
shown here are from the chick embryo.
As long as the beating cells do not touch one
another, their beats are independent - some
are faster, some are slower. But after two or
three days, the myocytes form interconnected
sheets of cells (monolayers, shown right) that
beat in unison. Pores (gap junctions) open
between adjacent touching cells, making their
cytoplasms interconnected. It is these gap
junctions that ensure that the connected cells
work as one.
If the cells of the adult don't beat in unison,
heart arrythmias can occur. Electronic
pacemakers may sometimes be used in a
patient whose heart doesn't beat in rhythm.
Cell Structures Quiz
Tomorrow!
Be prepared to identify structures
in both plant and animal cells
And
Describe the function of each
structure.
1. What kind of cell is this?
2
3
4
5
10
9
8
7
6
11. What kind of cell is this?
13
12
14
23
15
16
17
18
22
19
21
20
Extra Credit Opportunity!
 Create a model of either an animal cell
or a plant cell that includes all of the
structures we have discussed and
indicates the function of each of the
structures.
 Must be turned in no later than 1 week
prior to the end of the current six weeks
grading period.