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1
Biology
112Unit
Three
Chapter
Four
2
Cell
Sizes
• Smallest ‐ Bacteria• Largest
‐ Bird
egg• Longest ‐
Giraffe’s
Nerve
Cell• Most
Cells ‐ Diameter
of
0.7µm to
105
µm
3
Human height
Length of somenerve andmuscle cells
10 m
Frog egg
Chicken egg
Una
ided
eye
1 m
100 mm(10 cm)
10 mm(1 cm)
1 mm
Ligh
t mic
rosc
ope
Elec
tron
mic
rosc
ope
100 nm
100 µm
10 µm
1 µm
Most plant and animal cells
Viruses
NucleusMost bacteriaMitochondrion
10 nm
Lipids
Ribosome
Proteins
Mycoplasmas(smallest bacteria)
1 nmSmall molecules
0.1 nm Atoms
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4
How
big
can
a
cell
get?
• Cells
are
limited
by
natural
laws•
They
must
be
able
to
house
organelles(minimum
size)
•
They
must
stay
within
a
certain
surface
areato
volume
raRo
(maximum
size)
5
Surface
Area
• L
x
W
6
Volume
• L
x
W
x
H
• Large
cell
=
smaller
SA/Vol
raRo
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7
30 µm
30 µm 10 µm
10 µm
Surface areaof one large cube= 5,400 µm2
Total surface areaof 27 small cubes= 16,200 µm2
8
Cell
Structure
• Minimal
Cell1.
Plasma
membrane
2.
Cytoplasm
3.
GeneRc
informaRon
4.
Ribosomes
9
Two
Types
of
Cells
• ProkaryoRc• EukaryoRc
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10
ProkaryoRc
Cells
• Average
2
µm
to
8
µm
long• No
nucleus–
Nucleoid
(nuclear
region)
• Most
have
a
bacterial
cell
wall– PepRdoglycan
• Limited
organelles– Ribosomes
11
ProkaryoRc
Cells
• Variety
of
structures– Capsule
• Some
have
sRcky
outer
coat– Pili
or
flagella
• Used
for
movement
12
Nucleoid
Ribosomes
Plasma membrane
Cell wall
Capsule
Flagella
Bacterialchromosome
A typical rod-shapedbacterium
Pili
A thin section through thebacterium Bacillus coagulans(TEM)
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13
EukaryoRc
Cells
• Average
10x
bigger
and
1000x
in
volume
asprokaryoRc
• Nucleus
present• Variety
of
membranous
cellular
organelles•
Vary
in
cellular
metabolism
– Dependent
on
internal
cellular
membranes–
Increase
areas
of
specializaRon
•
Increase
in
SA
allows
for
more
reacRons
to
takeplace
at
one
Rme
14
Unicellular
• ProRsta– The
kingdom
being
reorganized
• Fungi– Yeast
15
MulRcellular
• Plant– No
centrioles– Cell
wall
(cellulose)– Chloroplast–
Central
vacuole
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16
Smooth endoplasmicreticulum
Rough endoplasmicreticulum
CYTOSKELETON:
NUCLEUS:Nuclear envelopeChromosomeNucleolus
Ribosomes
Golgiapparatus
Plasma membrane
Mitochondrion
Peroxisome
Cell wall
Central vacuoleMicrotubule
Intermediatefilament
Microfilament
Cell wall ofadjacent cell
Chloroplast
Plasmodesmata
17
MulRcellular
• Animal– Paired
centrioles– No
cell
wall–
Flagella
in
some
(movement)– ContracRle
vacuole
18
Smooth endoplasmicreticulum
Roughendoplasmicreticulum
CYTOSKELETON:
NUCLEUS:Nuclear envelopeChromosomesNucleolus
Ribosomes
Golgiapparatus
Plasma membrane
Mitochondrion
Peroxisome
Centriole
Lysosome
MicrotubuleIntermediatefilamentMicrofilament
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19
Organelles
and
FuncRons
• Four
Categories1.
Manufacturing
2.
Breakdown
3.
Energy
Processing
4.
Support,
Movement
and
CommunicaRon
20
Manufacturing
• Nucleus
–
control
center
of
the
cell– Nuclear
Envelope
• Double
membrane• Perforated
(pores)• Material
movement
– DNA• ChromaRn
strands• Strands
make
up
chromosomes
– Nucleolus• Contains
chromaRn,
RNA
and
protein•
Manufactures
ribosome
21
Two membranes ofnuclear envelope Nucleus
Nucleolus
Chromatin
Pore
Endoplasmicreticulum
Ribosomes
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22
Ribosomes
• Assemble
amino
acids
into
polypepRdes•
Every
cell
has
ribosomes!
23
Cytoplasm
Endoplasmic reticulum (ER)
Free ribosomes
Bound ribosomes
RibosomesER
Smallsubunit
Diagram of a ribosome
TEM showing ERand ribosomes
Largesubunit
24
• Endoplasmic
ReRculum
(ER)– Rough
ER
(due
to
ribosomes)
• Makes
membrane
bound
proteins• Makes
secretory
proteins
– Smooth
ER• Synthesis
of
lipids•
In
the
liver,
helps
regulate
blood
sugar• Drug
breakdown•
Storage
of
calcium
–
Amount
of
Smooth
ER
or
Rough
ER
in
the
cells
depends
onthe
funcRon
of
the
cell
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25
Smooth ER
Nuclearenvelope
Ribosomes
Rough ER
26
Transport vesiclebuds off
Secretoryproteininside trans-port vesicle
Glycoprotein
Polypeptide
Ribosome
Sugarchain
Rough ER
1
2
3
4
27
• Golgi
Apparatus–
Receives
and
modifies
substances
manufacturedin
the
ER
– Finishes,
sorts
and
ships
products–
#
of
GA
depend
on
how
acRve
the
cell
is
insecreRng
proteins
– Receiving
and
Shipping
sides
(cis
and
trans)–
Contents
may
either
leave
the
cell
or
become
partof
the
cell’s
organelles
or
membrane
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28
Golgi apparatusGolgi apparatus
“Receiving” side ofGolgi apparatus
Transportvesiclefrom ER
New vesicleforming
“Shipping” sideof Golgi apparatus
Transportvesicle fromthe Golgi
29
Breakdown• Lysosomes
– DigesRve
enzymes
(hydrolyRc)
in
a
membranous
sac–
Only
work
in
a
very
acidic
environment–
“Stuff”
that
needs
to
be
broken
down
is
brought
into
themembranous
sac
(recycling)
– Engulfing
bacteria– Fusing
with
food
vacuoles–
Embryonic
development
(programmed
cell
death)
30
Digestiveenzymes
Lysosome
Plasmamembrane
Food vacuole
Digestion
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31
Lysosome
Vesicle containingdamaged mitochondrion
Digestion
32
• Peroxisomes–
Contains
enzymes
in
a
membranous
sac
thatproduce
H2O2
– Help
survive
environmental
toxins
includingalcohol
– Help
the
cell
use
oxygen
to
break
down
faky
acids
33
• Vacuoles– In
plants,
can
be
a
large
lysosome
•
Can
store
water,
chemicals,
pigments,
poisons
or
wasteproduct
–
In
animals,
used
as
a
contracRle
vacuole
tomaintain
water
balance
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34
Nucleus
Chloroplast
Centralvacuole
35
Nucleus
Contractilevacuoles
36
Energy
Processing
• Mitochondria– Energy
converRng
organelle–
Cellular
RespiraRon
•
ConverRng
chemical
energy
in
food
to
chemical
energyof
ATP
for
cellular
work
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37
• Mitochondria
(conRnued)–
Double
membrane
–
two
compartments
(outer
and
inner
membranes)
1. Intermembrane
space
‐
between
the
membranes
–
where
H+
build
upoccurs
2. Cristae
‐
increase
surface
area
for
ATP
producRon
‐
ATP
Synthase
is
embedded
here
3. Mitochondrial
matrix
‐
The
Citric
Acid
Cycle
is
located
here
38
Mitochondrion
Intermembranespace
Innermembrane
Cristae
Matrix
Outermembrane
39
Support,
Movement
&CommunicaRon
• Cilia– Microtubule
extending
from
cell–
Short
and
many
present–
Line
trachea
to
sweep
mucous
containing
debrisout
of
lungs
– Line
oviducts
to
move
the
egg
toward
the
uterus
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40
Cilia
41
• Flagella– Fewer
in
number
but
longer– Sperm
42
Flagellum
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43
• Both– Dynein
arms
for
movement
(9
+
2)
arrangement–
Anchor
in
basal
body–
Are
tubular
extensions
of
the
plasma
membrane–
FuncRon
is
to
move
either
the
whole
cell
or
movematerial
across
cell
or
into
cell
44
Centralmicrotubules
Outer microtubuledoublet
Radial spoke
Dynein arms
Plasmamembrane
Triplet
Cross sections:
Flagellum
Basal body
Basal body
45
• Animal
Cell
Surfaces–
Animal
and
other
eukaryotes
are
organized
intosingle
funcRonal
organisms
– These
are
held
together
with
cell
surfaces
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46
• Extracellular
Matrix–
Helps
hold
cells
together,
affects
cell
behavior
bycontacRng
proteins
in
plasma
membrane
andcytoskeleton
within
the
cell
47
EXTRACELLULAR FLUID
Microfilaments
Collagen fiber
Connectingglycoprotein
Integrin
Plasmamembrane
Glycoproteincomplex with longpolysaccharide
CYTOPLASM
48
Binds
Cells
Together
1.
Tight
JuncRons‐
leak
proof
sheet‐
digesRve
or
nervous
system
2. Anchoring
JuncRons‐
rivets
with
cytoskeleton
3.
CommunicaRng
(Gap)
JuncRons‐
allow
for
flow
of
water
and
chemicals‐
also
for
electrical
signals
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49
Tight junctions
Anchoring junction
Gap junctions
Plasma membranesof adjacent cells
Extracellular matrix