- Explain the molecular events that occur, and what is being checked, at the G2 checkpoint.
GIGYUIm A ES - cdr )and Cyolin B CM - Cala]
.
omromatidsheld
4 After resll cath
on - sisthr
togetnerby oohesins t stahy 5 mi maay ]
)
Unil separated by ap
arute oleorhbje
G second
GI
ary growth pmase
-
,
ntheslsy of mtofitspindle requiredforcaldivision
'
s proteins
t
ived
s
ayulin C oyblsn
A EBUI
EYoin -GAKI
MpMoSphoMafron
OfT 5IMr 8
o -
-
t A
expresron ot protrerts heed tn pduk nt ; formspimodre ,hold ssszer ohrromaids
fogether .
t matinondensatrom
o
oylim podrced phosphoylates proteinsthaat regullbite ioo
hh -
UT asbemsly and nrebeare n r
elope ovcakooon 。
o
passing oheekpoint mggers tme sTartof M
mitosi
-phate
G mitotheBlesare aefivated by
MItosts PoMoting TCtor EMPF -
CBRIIGEIIMB
phospronyloation
OUPF is acfiratedbyEBC 25;
d phosphathses thatremorestheinmibtory
and
phorphomylatesCBEI5 ,
③ Tne aufivatds -CDK MAs ⑤ feedbaclh oop tMat mdsmtainsits wmcerrtraaio
③ 5BNA i )
darmaged, thecallogthe is arvasted viainactiratnos CBC
phosphatase Lvra n lothher himase]
prosphomyratzon .
- Explain the molecular events that occur, and what is being checked, at the metaphase
checkpoint.
M -
Y B
CUIM
.
☆
① 的 M
cuylhin centmolesare
dyoneated and
beginstotomm
spjnodhe
-
③ iuElear eivelope disbolves
③ Completom Of DBA condensation
④ oversees
otmer telnafes
assermbly polaity amdatolummen 1 , 5of
e
spsnadle to the hsnetochozh ,
s
Metuprase t
0 Anaphale Transinon
o
cuylin s has to se eliominated
i n order for Anaprase to be
imiMated
o
pl -
cay olimdegraadatt on will be followed
immedlaately by osromartrd
s . paration, andcompleton ofmitogty ,80 yElii reneedld fmtsstaage @ .
0
ABCIC Eshe above了 ,
AETUATIRG
CDC OSUB 以☆IT
indaive
↳
“ mmain
5
Bolyu iqs
的
AP / —
Begradanom of
iduivenuce EyGimin
M -
了职
pntedsome
~
-
m
ayclim
邐
骤
↓
,
u 以5 guitim
绍
ubidhiyla7om
nzymes
&
-
APE 1 C also
degradel 8 ebrrin t to
separdseispermitel aet
secuin ueeps separal inay
晚品
Nsesunn
,
heedspbenrseparato
inaivetom ,
cacco
f
算 lesmyed
了 之 ,
叭
, 3 .
的 O江包
inauireApclc atireouyc
AP CIC KIC EBC 2O bound O
“ anddegradapon ABG
,Merderian inhentance Patterrns
AutoSOmal UOGUHO 信 } 说BL
时
gerseratiom ?
chiidvanattoert
lalte
smoms areny
ugs
I
E
Ψ lyes
naveitd ? mom
nO
uts
如
~ 0
x x do all ml afflated
☆ gtmeymimg
ehSh
BOMINANT
dad hive it
绍ECSSiVE -
时1结 w0
S &x _
Linked 0
sometnimgalze mstochondMaltimmerifamue
( dfteremee
bpmm
male
i nrerto
fermale ? _
0
1
fyes
^
pmo
bex _
Limeed Arrtosomal
了 moreboysthangizls
l
U
☆ lineed OTI 的 R
E
…
1
…
→
. Alleiic
Heterogeneity Ai , Aa ,
A
3
toqrus
Heteroglherty Agone
,
3game
.
Rediued peretram le → O
与ympoms
[
o
AD
fenoypeamatst
[ on a
o
xpressinfys
voaraste
wntinucum
xpresti
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焱
0
nosymphrnd
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Pematresoue
vaamable
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1000
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,UNIT 4: The Endomembrane System
Endomembrane system organelles:
- Plasma membrane
- Early endosome
- Lysosome
- ER à
- Golgi à a series of flattened fluid-containing stacks (cisternae). Glycosylation, packaging and sorting
occurs here
ER (budding of the vesicles off of the tER ) à (vesicles attach at the Golgi) Golgi à Maturation of proteins through
the Golgi) à proteins can then be transported outside of the cell or embedded in the cell membrane itself
Major subdivisions of the endomembrane system:
- Secretory
- Endocytic
- Recycling and retrieval
The endomembrane system is a bunch of membrane compartments that are involved in
1) Processing à All proteins are processed once they are translated through the ribosomes
- Cytosolic proteins are processed through
o Folding
o Covalent modification (phosphorylation, acetylation, methylation)
o Cleavage
- Proteins of the endomembrane system are processed through
o Folding
o Disulfide bond formation
o Covalent modification
o Glycosylation
2) Movement of proteins and membrane à
- The requirements for protein important into an organelle is that there are:
o Specific sorting/targeting signal sequence in the primary sequence
§ They direct the protein to their required/specific organelle
§ Must be present in order for the protein to leave the cytosol ex: NLS for
nuclear import
§ The signal for entry into the ER is recognized before translation of the
protein is completed there is an import sequence into the ER and there is a
retention sequence for the lumen of ER (KDEL)
o A Specific protein receptor(s) in the organelle of interest
Entrance into the endomembrane system is conducted by smooth ER and the rough ER
- RER are sites of secretory protein synthesis à secretory pathway (co-translational transfer Commented [OA1]: The protein is translated by the
across the RER membrane then transported by vesicular traffic to the Golgi). ribosomes in the RER into the ER lumen
- SER are sites of lipid and steroid synthesis (lipid biosynthesis)
Commented [OA2]: Each of the vesicles have a lipid bilayer
- RER have ribosomes docked on them while SER don’t
- ER is the starting point for proteins traveling the endomembrane system
- ER conducts quality control and protein folding (chaperone proteins), checking for defective
proteins (not exporting them unless they are assembled properly)
- ER is the rite of post-translational modifications (disulfide bonds, glycosylation) Commented [OA3]: Via enzymes attach saccharides that
Proteins that would be expected to be sent to the ER are turn the proteins into glycoproteins so that they can be
1. Proteins destined for secretion destined for the cell membrane. Based on its overall
2. Membrane proteins that are inserted into the membrane of the ER as they are synthesized structure each protein can be recognized, packaged into a
during the translation process vesicle, and sent to a different compartment
a. Whether a ribosome becomes attached to the ER depends on the mRNA being
translated they all come from a common pool of ribosomes. They could either be
ribosomes that translate they cytosolic proteins. And destined for membrane-
bound organelle.
, i. Post-translational trafficking: nuclear proteins, mitochondrial and
chloroplast proteins (encoded by nuclear genes)
1. Ribosomes remain free in the cytosol and completed
polypeptide goes to its functional destination depending on its
sorting signal. Polypeptide may be folded or unfolded.
ii. Co-translational trafficking: ER/Golgi/lysosomal proteins, secreted
proteins, membrane proteins
1. Ribosomes attach to ER membrane. Protein is threaded
through ER membrane as it is being translated. Proteins either
stay in ER or move to other compartments of the
endomembrane system.
3. Resident proteins of the ER, Golgi, and lysosome
Co-translational Trafficking a Closer Look
ER Signal Sequence and Signal Recognition Particle (SRP) direct ribosome to ER membrane.
- SRP binds to the exposed N-terminal ER signal sequence (‘Start transfer sequence’) and to ribosomes
(slowing protein synthesis) àsignal sequences are both necessary (loss-of-function) and sufficient (gain-
of-function) to direct proteins to ER
- Translation is paused
- SRP-ribosomes complex then bind to SRP receptor In the ER membrane Protein translocation channel
assembles and inserts the polypeptide chain into the membrane and starts its transfer across the bilayer,
translation resume
Signal Sequence
1. Start Transfer Sequence
- N-terminal signal sequence (N-
terminal Start Transfer Sequence)
- Initiates transfer of protein
across ER membrane
- Not a membrane crossing
domain (the N-terminus
ends up inside the ER
lumen) Commented [OA4]: A soluble protein crosses the ER
- Is cleaved off by signal membrane into the lumen and only has the N-term
peptidase sequence.
- Internal start transfer sequence
- Initiates transfer of protein
across the ER membrane
- Is a membrane crossing domain
- Not cleaved off
2. Stop Transfer Sequence
GIGYUIm A ES - cdr )and Cyolin B CM - Cala]
.
omromatidsheld
4 After resll cath
on - sisthr
togetnerby oohesins t stahy 5 mi maay ]
)
Unil separated by ap
arute oleorhbje
G second
GI
ary growth pmase
-
,
ntheslsy of mtofitspindle requiredforcaldivision
'
s proteins
t
ived
s
ayulin C oyblsn
A EBUI
EYoin -GAKI
MpMoSphoMafron
OfT 5IMr 8
o -
-
t A
expresron ot protrerts heed tn pduk nt ; formspimodre ,hold ssszer ohrromaids
fogether .
t matinondensatrom
o
oylim podrced phosphoylates proteinsthaat regullbite ioo
hh -
UT asbemsly and nrebeare n r
elope ovcakooon 。
o
passing oheekpoint mggers tme sTartof M
mitosi
-phate
G mitotheBlesare aefivated by
MItosts PoMoting TCtor EMPF -
CBRIIGEIIMB
phospronyloation
OUPF is acfiratedbyEBC 25;
d phosphathses thatremorestheinmibtory
and
phorphomylatesCBEI5 ,
③ Tne aufivatds -CDK MAs ⑤ feedbaclh oop tMat mdsmtainsits wmcerrtraaio
③ 5BNA i )
darmaged, thecallogthe is arvasted viainactiratnos CBC
phosphatase Lvra n lothher himase]
prosphomyratzon .
- Explain the molecular events that occur, and what is being checked, at the metaphase
checkpoint.
M -
Y B
CUIM
.
☆
① 的 M
cuylhin centmolesare
dyoneated and
beginstotomm
spjnodhe
-
③ iuElear eivelope disbolves
③ Completom Of DBA condensation
④ oversees
otmer telnafes
assermbly polaity amdatolummen 1 , 5of
e
spsnadle to the hsnetochozh ,
s
Metuprase t
0 Anaphale Transinon
o
cuylin s has to se eliominated
i n order for Anaprase to be
imiMated
o
pl -
cay olimdegraadatt on will be followed
immedlaately by osromartrd
s . paration, andcompleton ofmitogty ,80 yElii reneedld fmtsstaage @ .
0
ABCIC Eshe above了 ,
AETUATIRG
CDC OSUB 以☆IT
indaive
↳
“ mmain
5
Bolyu iqs
的
AP / —
Begradanom of
iduivenuce EyGimin
M -
了职
pntedsome
~
-
m
ayclim
邐
骤
↓
,
u 以5 guitim
绍
ubidhiyla7om
nzymes
&
-
APE 1 C also
degradel 8 ebrrin t to
separdseispermitel aet
secuin ueeps separal inay
晚品
Nsesunn
,
heedspbenrseparato
inaivetom ,
cacco
f
算 lesmyed
了 之 ,
叭
, 3 .
的 O江包
inauireApclc atireouyc
AP CIC KIC EBC 2O bound O
“ anddegradapon ABG
,Merderian inhentance Patterrns
AutoSOmal UOGUHO 信 } 说BL
时
gerseratiom ?
chiidvanattoert
lalte
smoms areny
ugs
I
E
Ψ lyes
naveitd ? mom
nO
uts
如
~ 0
x x do all ml afflated
☆ gtmeymimg
ehSh
BOMINANT
dad hive it
绍ECSSiVE -
时1结 w0
S &x _
Linked 0
sometnimgalze mstochondMaltimmerifamue
( dfteremee
bpmm
male
i nrerto
fermale ? _
0
1
fyes
^
pmo
bex _
Limeed Arrtosomal
了 moreboysthangizls
l
U
☆ lineed OTI 的 R
E
…
1
…
→
. Alleiic
Heterogeneity Ai , Aa ,
A
3
toqrus
Heteroglherty Agone
,
3game
.
Rediued peretram le → O
与ympoms
[
o
AD
fenoypeamatst
[ on a
o
xpressinfys
voaraste
wntinucum
xpresti
多mpoms
,a l l sym
|
焱
0
nosymphrnd
。 redled
Pematresoue
vaamable
Qxrezzst 7rmy
Aa
1000
然 om
,UNIT 4: The Endomembrane System
Endomembrane system organelles:
- Plasma membrane
- Early endosome
- Lysosome
- ER à
- Golgi à a series of flattened fluid-containing stacks (cisternae). Glycosylation, packaging and sorting
occurs here
ER (budding of the vesicles off of the tER ) à (vesicles attach at the Golgi) Golgi à Maturation of proteins through
the Golgi) à proteins can then be transported outside of the cell or embedded in the cell membrane itself
Major subdivisions of the endomembrane system:
- Secretory
- Endocytic
- Recycling and retrieval
The endomembrane system is a bunch of membrane compartments that are involved in
1) Processing à All proteins are processed once they are translated through the ribosomes
- Cytosolic proteins are processed through
o Folding
o Covalent modification (phosphorylation, acetylation, methylation)
o Cleavage
- Proteins of the endomembrane system are processed through
o Folding
o Disulfide bond formation
o Covalent modification
o Glycosylation
2) Movement of proteins and membrane à
- The requirements for protein important into an organelle is that there are:
o Specific sorting/targeting signal sequence in the primary sequence
§ They direct the protein to their required/specific organelle
§ Must be present in order for the protein to leave the cytosol ex: NLS for
nuclear import
§ The signal for entry into the ER is recognized before translation of the
protein is completed there is an import sequence into the ER and there is a
retention sequence for the lumen of ER (KDEL)
o A Specific protein receptor(s) in the organelle of interest
Entrance into the endomembrane system is conducted by smooth ER and the rough ER
- RER are sites of secretory protein synthesis à secretory pathway (co-translational transfer Commented [OA1]: The protein is translated by the
across the RER membrane then transported by vesicular traffic to the Golgi). ribosomes in the RER into the ER lumen
- SER are sites of lipid and steroid synthesis (lipid biosynthesis)
Commented [OA2]: Each of the vesicles have a lipid bilayer
- RER have ribosomes docked on them while SER don’t
- ER is the starting point for proteins traveling the endomembrane system
- ER conducts quality control and protein folding (chaperone proteins), checking for defective
proteins (not exporting them unless they are assembled properly)
- ER is the rite of post-translational modifications (disulfide bonds, glycosylation) Commented [OA3]: Via enzymes attach saccharides that
Proteins that would be expected to be sent to the ER are turn the proteins into glycoproteins so that they can be
1. Proteins destined for secretion destined for the cell membrane. Based on its overall
2. Membrane proteins that are inserted into the membrane of the ER as they are synthesized structure each protein can be recognized, packaged into a
during the translation process vesicle, and sent to a different compartment
a. Whether a ribosome becomes attached to the ER depends on the mRNA being
translated they all come from a common pool of ribosomes. They could either be
ribosomes that translate they cytosolic proteins. And destined for membrane-
bound organelle.
, i. Post-translational trafficking: nuclear proteins, mitochondrial and
chloroplast proteins (encoded by nuclear genes)
1. Ribosomes remain free in the cytosol and completed
polypeptide goes to its functional destination depending on its
sorting signal. Polypeptide may be folded or unfolded.
ii. Co-translational trafficking: ER/Golgi/lysosomal proteins, secreted
proteins, membrane proteins
1. Ribosomes attach to ER membrane. Protein is threaded
through ER membrane as it is being translated. Proteins either
stay in ER or move to other compartments of the
endomembrane system.
3. Resident proteins of the ER, Golgi, and lysosome
Co-translational Trafficking a Closer Look
ER Signal Sequence and Signal Recognition Particle (SRP) direct ribosome to ER membrane.
- SRP binds to the exposed N-terminal ER signal sequence (‘Start transfer sequence’) and to ribosomes
(slowing protein synthesis) àsignal sequences are both necessary (loss-of-function) and sufficient (gain-
of-function) to direct proteins to ER
- Translation is paused
- SRP-ribosomes complex then bind to SRP receptor In the ER membrane Protein translocation channel
assembles and inserts the polypeptide chain into the membrane and starts its transfer across the bilayer,
translation resume
Signal Sequence
1. Start Transfer Sequence
- N-terminal signal sequence (N-
terminal Start Transfer Sequence)
- Initiates transfer of protein
across ER membrane
- Not a membrane crossing
domain (the N-terminus
ends up inside the ER
lumen) Commented [OA4]: A soluble protein crosses the ER
- Is cleaved off by signal membrane into the lumen and only has the N-term
peptidase sequence.
- Internal start transfer sequence
- Initiates transfer of protein
across the ER membrane
- Is a membrane crossing domain
- Not cleaved off
2. Stop Transfer Sequence
