Chapter 3 The Cell Endomembrane S yste m E ndoplasmic Reticulum G olgi Apparatus Lysosomes P eroxisome s V acuoles Vesicles Overview Play ke ID: 566088
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Slide1
2005-2006
Chapter 3
The
Cell:
Endomembrane
S
yste
m
–
E
ndoplasmic
Reticulum,
G
olgi
Apparatus, Lysosomes
,
P
eroxisome
s
,
V
acuoles
,
VesiclesSlide2
Overview
Play
key
role in
synthesis (& hydrolysis)
of macromolecule
s in
cellVarious “p
layers”
modify macromolecules
for various functionsSlide3
Endoplasmic Reticulum
Function
m
anufactures
membrane
s &
performs
many bio-synthesis functions
Structure
me
mbrane connected t
o
nuclear envelop
e &
extend
s
throughou
t
cel
l
account
s
fo
r
50
%
m
e
m
brane
s
i
n
eukaryoti
c
cel
l
roug
h
ER
=
bound
ribosomes
smoot
h
ER
=
no
ribosomesSlide4
2005-2006
A
P Biolog
y
Types of ERSlide5
Smooth ER function
Factory
processing operations
man
y metabolic
processes
synthesi
s & hydrolysis
enzymes
of sm
ooth ER…
synthesize
lipids,
oils, phospholipids,
steroid
s &
se
x
hormones
hydrolysis
(breakdown)
of
glycogen
(in
liver)
into
glucose
detoxify
drugs
&
poisons
(in
liver)
ex.
alcohol
&
bar
bituratesSlide6
2005-2006
Roug
h ER function
Produce
proteins for
export
out of
cellprotein
secretin
g cells
packaged into transport vesicle
s
for export
which
cells have
a
lot
o
f
rou
gh
ER
?Slide7
2005-2006
S
ynthesize m
embrane
phospholipids
build new mem
brane
as ER membran
e expands, bud
off &
transfer to other parts of
cell
that
need membranes
S
ynthesiz
e
m
e
m
bran
e
protein
s
membrane
b
ou
n
d
proteins
sy
nthesized directly
into
membraneprocessing to make glycoproteins
Membrane FactorySlide8
A
P Biology
2005-2006Slide9
A
P Biology
2005-2006Slide10
2005-2006
AP
Biology
Golgi
Apparatus
Function
finishes, sorts,
& ships cell
products
“shipping
& receiving department
”
center
of m
anufacturing
,
w
arehousing
,
sortin
g
&
shippin
g
extensiv
e
i
n
cell
s
specialize
d
for secretionwhich cells have a
lot of Golgi?Slide11
2005-2006
Golgi Apparatus
Structure
flattened m
embranous
sacs =
cisternae
look like stack
of pita
bread
2 sides = 2
functions
ci
s = receive
s
materia
l
by
fusing
with
vesicle
s
=
“
r
eceivin
g
”
trans
buds
off
vesicles
that travel to other sites= “shipping”
(tran
s
p
ort)
cis
transSlide12
A
P Biology
2005-2006
Golgi ApparatusSlide13
2005-2006
Golgi
processing
During
path from
cis to trans,
products
from ER are modified
into final
form
tags, sorts, & packages
materials
into transport
vesiclesG
olg
i
=
“
U
P
S
headquarter
s”
Transpor
t
vesicle
s
=
“
U
P
S
trucks”delivering packages that have been tagged with
their own
barcodesSlide14
B
iology 2005-2006
AP
Putting
it together…
“
Le
t’s go to
the video tape
!”Slide15
2005-2006
onl
y in
animal
cells
Lysosomes
Structure
membrane-bounded
sac
of hydrolytic
enzymes that digest
s m
acrom
oleculesenzyme
s &
membran
e
of
lysosomes
are synthesize
d
by
roug
h
ER
&
transferred
to
the
GolgiSlide16
2005-2006
Lysosomes
Function
a little
“stomac
h” fo
r the cel
llyso– =
breaking
things apart
–some =
body
also
the “c
lea
n
u
p
cre
w
”
o
f
th
e
cel
l
1974
Nobel
prize:
Christian
de Duve Lysosomes discovery in
1960s
196
0
|
1
97
4Slide17
2005-2006
Cellular digestion
Lysosom
es
fuse with
fo
od vacuoles
Polymers are digested
into monom
ers
pass to cytosol
to become nutrients
of
cellSlide18
The
Recycler
Fus
e
w
it
h
organelle
s
or
macro
molecules in
cytoso
l
t
o
recycl
e
m
aterial
s
W
he
r
e
o
l
d
p
r
o
t
eins go to die!Slide19
enzymes
are very
sensitive
to pH
why?enzymes
are
proteins —
pH affects structure
why evolv
e digestive
enzymes which function at
pH different
from c
ytosol?
digestive
enzymes
w
o
n
’
t
function
w
ell
if
leak
into cytosol
=
don’t want to digest yourself!
Lysosomal enzymes
Lysosom
al
e
nzy
m
es
w
ork
best
at
p
H
5
organelle
create
s
custo
m pH
how?
proteins
in
lysos
o
m
al
m
embrane
p
u
mp
H
+
io
ns
from
the
cytosol
into
lyso
some
why?Slide20
2005-2006
W
hat if
a l
ysomom
e digestiv
e enzym
e doesn’t function?
don
’t
digest a biomolecule
instead
biomolecule collects in lysosomes
lysosomes
fill
up
with undigested
material
lysosomes
g
row
larger
&
larger
eventuall
y
disrupt
cel
l
&
organ function“Lysosoma
l storage
disease
s
”
ar
e
usuall
y
fata
l
Tay-
S
achs
d
isease
lipids
build
up
in
brain
cells
child
dies
before
ag
e
5
Tay-
S
achs
When
things
go
wron
g
…Slide21
A
P Biology
Sometimes
its supposed to work
that wa
y…
Apoptosis = cell
death
critical
role in progra
mmed
destruction
of cells
i
n
m
ulticellula
r
organis
m
s
auto-destruc
t
mechanism
“c
ell
suicide”
som
e
cell
s
have to die in an
organized fashion, especiall
y
during
development
e
x
:
d
evelopme
nt
of
space
bet
ween
yo
ur
fin
gers
during
embryonic
devel
o
pm
ent
e
x
:
if
cell
grows
i
mpro
perly
this
s
e
lf-
des
tru
c
t
mechan
i
s
m
is
triggered
to
re
move
damaged cellcancer over-rides this to enable tumor
growthSlide22
2005-2006
Other
digestive enzyme sacs
in
both
animal
s & plants
breakdown
fatty
acids to sugar
s
easier
to transport & use a
s
energ
y
source
detoxif
y
cel
l
detoxifies
alcoho
l
& other
poisons
produc
e
peroxid
e
(
H
2
O2)must breakdown H2
O2
H
2
O
PeroxisomesSlide23
2005-2006
AP
Biology
Vacuoles
& vesicles
Function
little
“transfer ships”
Food vacuoles
phagocytosis,
fuse with
lysosome
s
Contractile vacuoles
i
n
fresh
w
ate
r
protist
s
,
pu
m
p
exces
s
H
2
O
ou
t
o
f cellCentral vacuolesin many mature
plant cellsSlide24
2005-2006
Vacuoles in
plants
Functions
storage
stockpiling
proteins or
inorganic ionsdepositing
metabolic
byproducts
storing pigmentsstorin
g
defensive compounds
against herbivores
selectiv
e
membrane
contro
l
w
ha
t
co
m
e
s
i
n
o
r
goe
s
ou
tSlide25
A
P Biology
2005-2006
Putting it all
together…