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http://www.dnatube.com/video/55
1/The-Inner-Life-Of-A-Cell-HQ
Tour of the Cell 1
AP Biology
2013-2014
Cytology: science/study of cells
To view cells:
Light microscopy
resolving power: measure of clarity
 Electron microscopy – electron beam
TEM: to study cell internal ultrastructure
SEM: to study cell surfaces
AP Biology
http://www.vcbio.science.ru.nl/en/fes
em/info/cryosem/
SEM
Foraminifera
(a protist)
dog flea
Leaf part
 Cool
images
http://www.vcbio.science.r
u.nl/en/fesem/applets/flea/
Polysterene
aggregate
Micro- & nano
organisms
Leaf (guard cells)
AP Biology
Pb(Zr, Ti)O3
hair
Cytology: science/study of cells
To isolate organelles:
Cell fractionation: to separate major organelles
Ultracentrifuge: cell fractionation;
130,000rpm or 1,000,000 g
http://www.youtube.com/watch?v=8B
nES4T1RDk
AP Biology
Organelle Isolation:
Cell Fractionation & Ultracentrifugation
NUCLEI
MITOCHONDRIA
MEMBRANES ROUGH
ENDOPLASMIC
RETICULUM
AP Biology
Centrifuge at LOW SPEED
for 10 minutes
Centrifuge at MODERATE
SPEED
for 15 minutes
Centrifuge at HIGH SPEED
for 30 minutes
Size is relative
AP Biology
http://htwins.net/scale2/
http://www.cellsalive.com/howbig.htm
Cell Size
http://learn.genetics.utah.edu/content/begin/cells/scale/
AP Biology
Cell Size
SA = 4 r2
V = 4/3 r3
Cell Radius
SA (r2)
V (r3)
SA/V (r2/r3)
r
1
1
1
1
3
9
27
1/3
4
16
64
1/4
r
SA/V
V and SA
V
AP Biology
2
4
8
1/2
>
SA
Cell Size
As cell size increases, the SA to V ratio
decreases
Rates of chemical exchange may then be
inadequate for cell size
Cell size, therefore, remains small
What happens
when the cell
reaches a
critical size?
AP Biology
Types of cells
Prokaryote
bacteria cells
- no organelles
- organelles
Eukaryote
animal cells
AP Biology
Eukaryote
plant cells
http://www.yellowtang.org/animations/cell_features_v2.swf
AP Biology
Cell Types: Prokaryotic
Nucleoid: DNA
concentration
No organelles with
membranes
Ribosomes:
protein synthesis
Plasma membrane:
(all cells); semi-permeable
Cytoplasm/cytosol (all cells)
AP Biology
Prokaryotes contain no
organelles.
Organelles are
membrane bound.
Ribosomes are not
membrane bound.
Ribosomes are not
organelles.
Cell types: Eukaryotic
Nucleus:membrane enclosed organelle
containing chromosomes
Membrane bound organelles of
specialized form and function
 Generally larger than prokaryotic cells
AP Biology
Why organelles?
 Specialized structures

specialized functions
mitochondria
 cilia or flagella for locomotion
 Containers


partition cell into compartments
create different local environments
chloroplast
 separate pH, or concentration of materials

distinct & incompatible functions
 lysosome & its digestive enzymes
 Membranes as sites for chemical reactions


unique combinations of lipids & proteins
embedded enzymes & reaction centers
Golgi
 chloroplasts & mitochondria
AP Biology
http://www.cellsalive.com/cells/cell_model.htm
ER
Cells must work to live!
 What jobs do cells have to do?

make proteins
 proteins control every
cell function

make energy
 for daily life
 for growth

make more cells
 growth
 repair
 renewal
AP Biology
http://www.johnkyrk.com/aminoacid.ht
ml
http://www.rcsb.org/pd
b/101/static101.do?p=
education_discussion/
educational_resources/
index.html#PostersExhibits
AP Biology
http://sciencenetlinks.com/interactives/
protein.html
Building Proteins
http://www.phschool.com/
atschool/phsciexp/active_
art/protein_synthesis/inde
x.html
2013-2014
Proteins do all the work!
proteins
cells
DNA
AP Biology
organism
Repeat after me…
Proteins do all the work!
http://vcell.ndsu.nodak.edu/animations/proteinmodification/
movie-flash.htm
Cells functions
 Building proteins
read DNA instructions
 build proteins
 process proteins

 folding
 modifying
 removing amino acids
 adding other molecules


AP Biology
e.g, making glycoproteins
for cell membrane
address & transport proteins
Building Proteins
 Organelles involved
nucleus
 ribosomes
 endoplasmic reticulum
(ER)
 Golgi apparatus
 vesicles

The Protein Assembly Line
nucleus
AP Biology
ribosome
ER
Golgi
apparatus
vesicles
http://www.biostudio.com/demo_fre
eman_dna_coiling.htm
Nucleus
 Function
DNA
chromosome
protects DNA
Structure



histone protein
nuclear envelope
http://www.youtube.com/watch?
v=gbSIBhFwQ4s
 double membrane
 membrane fused in spots to create pores
 allows large macromolecules to pass through
nuclear
pores
What kind of
molecules need to
pass through?
AP Biology
nuclear
pore
nucleolus
nuclear envelope
DNA Wrapping
AP Biology
DNA Packaging
AP Biology
http://www.youtube.com/watch?v=4jtmOZa
IvS0&feature=related
1
nuclear
membrane
http://www.youtube.com/watch?v=I9ArIJWYZHI
production of mRNA
from DNA in nucleus
DNA
Build RNA
Nucleus
mRNA
http://www.dnalc.org/view/15889-RNApolymerase-game-interactive-2D-animation.html
http://www.dnalc.org/resources/3d/12-transcription-basic.html
2
nuclear pore
mRNA travels from
nucleus to ribosome
in cytoplasm through
nuclear pore
http://www.dnalc.org/view/15481-Translation-RNA-toAP Biology
protein-3D-animation-with-no-audio.html
small
ribosomal
subunit
mRNA
large
ribosomal
subunit
cytoplasm
What kind of
molecules
pass through
the pore?
AP Biology
Nucleolus
 Function

ribosome production
 build ribosome subunits from rRNA & proteins
 exit through nuclear pores to cytoplasm &
combine to form functional ribosomes
large subunit
small
subunit
AP Biology
rRNA &
proteins
ribosome
nucleolus
Ribosomes
large
subunit
 Function

small
subunit
protein production
 Structure


rRNA & protein
2 subunits combine
0.08mm
Ribosomes
Rough
ER
Smooth
ER
AP Biology
Types of Ribosomes
 Free ribosomes


suspended in cytosol
synthesize proteins that
function in cytosol
 Bound ribosomes


AP Biology
attached to endoplasmic
reticulum
synthesize proteins
for export or
for membranes
membrane proteins
Endoplasmic Reticulum
 Function



processes proteins
manufactures membranes
synthesis & hydrolysis of many compounds
 Structure

AP Biology
membrane connected to nuclear envelope &
extends throughout cell
Types of ER
rough
AP Biology
smooth
Smooth ER function
 Membrane production
 Many metabolic processes

synthesis
 synthesize lipids
 oils, phospholipids, steroids & sex hormones

hydrolysis
 hydrolyze glycogen into glucose
 in liver
 detoxify drugs & poisons
 in liver
ex. alcohol & barbiturates
AP Biology
Membrane Factory
 Build new
membrane

synthesize
phospholipids
 builds membranes

ER membrane
expands
 bud off & transfer
to other parts of
cell that need
membranes
AP Biology
Rough ER function
 Produce proteins for export out of cell
protein secreting cells
 packaged into transport vesicles for export

Which cells
have lot of
rough ER?
AP Biology
Build a protein
http://www.dnalc.org/view/15890-Ribosomegame-interactive-2D-animation.html
Synthesizing proteins
cisternal
space
polypeptide
signal
sequence
ribosome
ribosome
mRNA
membrane of
endoplasmic reticulum
http://www.dnalc.org/view/15481-TranslationAP Biology
RNA-to-protein-3D-animation-with-no-audio.html
cytoplasm
Golgi Apparatus
 Function

finishes, sorts, tags & ships cell products
 like “UPS shipping department”

ships products in vesicles
 membrane sacs
Which cells
have lots
of Golgi?
secretory
vesicles
 “UPS trucks”
transport vesicles
AP Biology
http://www.sumanasinc.com/webcontent/animati
ons/content/vesiclebudding.html
Golgi Apparatus
AP Biology
http://www.goldiesroom.org/Shockwave_P
ages/011--Golgi%20Complex.htm
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapte
r2/animation__lysosomes.html
Vesicle transport
protein
vesicle
budding
from rough
ER
migrating
transport
vesicle
ribosome
http://www.goldiesroom.org/Shockwave_Pages/
011--Golgi%20Complex.htm
AP Biology
fusion
of vesicle
with Golgi
apparatus
Vesicles
AP Biology
endoplasmic
reticulum
nucleus
protein
on its way!
DNA
RNA
vesicle
TO:
TO:
TO:
vesicle
ribosomes
TO:
finished
protein
protein
You should be able to label each step.
Golgi
apparatus
Making Proteins
Regents Biology
Putting it together…
nucleus
nuclear pore
Making proteins
cell
membrane
protein secreted
rough ER
ribosome
proteins
smooth ER
AP Biology
transport
vesicle
cytoplasm
vesicle
Describe
“making
proteins”?
Golgi
apparatus
Where
old organelles
go to die!
Lysosomes
 Function

little “stomach” of the cell
 digests macromolecules

“clean up crew” of the cell
 cleans up broken down
organelles
 Structure

vesicles of digestive
enzymes
synthesized by rER,
transferred
to Golgi
AP Biology
only in
animal cells
Lysosomes
1960 | 1974
white blood cells attack &
destroy invaders = digest
them in lysosomes
AP Biology
1974 Nobel prize: Christian de Duve
Lysosomes discovery in 1960s
http://highered.mcgrawhill.com/olc/dl/120067/bio01.swf
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapte
r2/animation__lysosomes.html
Cellular digestion
 Lysosomes fuse with food vacuoles

polymers
digested into
monomers
 pass to cytosol
to become
nutrients of
cell
vacuole
 lyso– = breaking things apart
AP Biology
 –some
= body
http://faculty.ccbcmd.edu/courses/bio141/lecguid
e/unit4/innate/acidification_phagosome.html
Lysosomal enzymes
 Lysosomal enzymes work best at pH 5


http://highered.mcgraworganelle creates custom pH
hill.com/olcweb/cgi/pluginpop.cgi?it=swf::5
35::535::/sites/dl/free/0072437316/120068
how?
/bio05.swf::Proton%20Pump
 proteins in lysosomal membrane pump H+ ions from
the cytosol into lysosome

why?
 enzymes are very sensitive to pH

why?
 enzymes are proteins — pH affects structure

why evolve digestive enzymes which function at
pH different from cytosol?
 digestive enzymes won’t function well if some leak into
cytosol = don’t want to digest yourself!
AP Biology
When things go bad…
 Diseases of lysosomes are often fatal
digestive enzyme not working in lysosome
 picks up biomolecules, but can’t digest one

 lysosomes fill up with undigested material

grow larger & larger until disrupts cell &
organ function
 lysosomal storage diseases
 more than 40 known diseases
Mutation in:
hexosaminidase
 example:
A, (helps break
Tay-Sachs disease
down
gangliosides) build up undigested
AP Biology
fat
in brain cells (autosomal rec)
Lysosomal storage diseases
 Lipids
Gaucher’s disease
 Niemann-Pick disease
 Tay Sachs

http://www.youtube.com/wa
tch?v=WbUpMBHioT8
 Glycogen & other polysaccharides
Farber disease
 Krabbe disease

 Proteins

AP Biology
Schindler’s disease
Niemann-Pick Disease
Lysosomal storage diseases
 Gaucher’s
-autosomal recessive disorder
-deficiency of glucocerebrosidase,
a lysosomal enzyme that catalyses
the hydrolysis of the glycolipid
glucocerebroside  ceramide + glucose
AP Biology
Lysosomal storage
disease
Hepatosplenomegaly courtesy of The
National MPS Society, Inc.
http://www.lysosomallearning.com/heal
thcare/about/lsd_hc_abt_niemann.asp
AP Biology
But sometimes cells need to die…
 Lysosomes can be used to kill cells when
they are supposed to be destroyed

some cells have to die for proper
development in an organism
 apoptosis
 “auto-destruct” process
 lysosomes break open & kill cell
 ex: tadpole tail gets re-absorbed
when it turns into a frog
 ex: loss of webbing between your
fingers during fetal development
AP Biology
Fetal development
syndactyly
6 weeks
15 weeks
AP Biology
Apoptosis
 programmed destruction of cells in multicellular organisms
programmed development
 control of cell growth

 example:
if cell grows uncontrollably this self-destruct
mechanism is triggered to remove damaged cell
 cancer must over-ride this to enable tumor
growth
AP Biology
AP Biology
AP Biology
Any Questions!!
AP Biology
2013-2014