Term
|
Definition
| the movement of fully charged ionic compounds though a viscuous medium by an electric field |
|
|
Term
|
Definition
| positive pole attracts anions (negative charges) |
|
|
Term
|
Definition
| negative pole attracts cations positive charges |
|
|
Term
|
Definition
anionic detergent at most phs used
seperates based on size, small proteins move faster, assume all proteins are denatured |
|
|
Term
| features of cytoskeletal components |
|
Definition
they are assembled from a pool of protein subunits
the polymer(filaments) are often dynamic, always changing by assembly and disassembly |
|
|
Term
|
Definition
subunit- alpha and beta tubulin
they combine together to make a tublin heterodimer. this polymerizes to make microtubules |
|
|
Term
|
Definition
| polymerizes to make filament |
|
|
Term
|
Definition
depolymerize to actin monomers
can form a double helix of filament |
|
|
Term
|
Definition
| this is the subunit for the protofilament polymer |
|
|
Term
|
Definition
| this is a linear polymer of tublin dimers |
|
|
Term
|
Definition
| cylinder made of 13 protofilaments lined up side by side |
|
|
Term
| order of microtubules from the smallest unit to the largest unit |
|
Definition
tublin forming up in alpha(-) and beta(+) ends
the tublin links up to make a protofilament
finaly the protofilaments line together to make a straw like shape |
|
|
Term
|
Definition
| required to bond to create a filament but not hydrolised when bonded |
|
|
Term
|
Definition
|
|
Term
|
Definition
singlet which is just one ring of 13 protofilaments
prone to cahnge, use in cell division and shape
tracks for transport |
|
|
Term
|
Definition
found in cilia or flagella
doublet= 23 protofilaments
arranged by an a tubule of 13 and a b tubule of 10 protomilaments
used for extracellular motility/movement of fluids |
|
|
Term
|
Definition
found in centrioles or basal bodies
comes in triplet form= 33 protofilaments
arranged by a ring of 13 followed by 2 rings of 10 protofilaments
seen in chromosomal seperation |
|
|
Term
| name the 4 ways to disrupt microtubules |
|
Definition
low temp=revisible lability
drugs like colchicine
high ca++ concentrations
low concentrations of GTP |
|
|
Term
| describe the structure of axoneme |
|
Definition
9+2 arrangement
9 gynenin arms found in a circle, these arms are made of doublet
the central sheath has 2 singlets in the center
each arme ras a radial spoke connecting the doublets to the central sheath |
|
|
Term
|
Definition
| bridges that hold the doublets together in the axonemal |
|
|
Term
|
Definition
are triplet microtubules and are the basal body of other centrioles
you would know if it is a basal body based on weather it is at the base of a microtubule |
|
|
Term
| pericentriolar material is the material around the centrioles |
|
Definition
material found around the centrioles
this serves a a microtubule organization center (MTOC) |
|
|
Term
|
Definition
2 centrioles make a centrosome
unique to animal cells
the centrosome is the site for the MTOC organizational center for the cytoplasmic growth of microtubules |
|
|
Term
| fluorescent conjugated proteins |
|
Definition
only labels new polymers of microtubes
the fluorescent dye is just covelantly bonded to the proteins, must be injected to cell |
|
|
Term
|
Definition
assume 1 antibody per protein
make the antibody flurecent, add it to cell
thus labels all polymers old and new that contain that protein with fluorecent antibodies |
|
|
Term
|
Definition
absorbs high energy releases low energy
or
absorbs short wavel releases long wave |
|
|
Term
| fluorescent conjugated tublin |
|
Definition
make tublin fluorescent
inject into cell
take lots of pics, only adds the growing(+) end |
|
|
Term
| at what temp does the mitotic spindle disapear |
|
Definition
| 0-4 celcius for sea urchin eggs |
|
|
Term
| at what temp do the mitotic spindles reform |
|
Definition
| 15 celcius for sea urchin only cytoplasmic |
|
|
Term
| what hypothesis explains cold lability |
|
Definition
| polymerization(sub units) and depolymerization(polymer) |
|
|
Term
| describe the exxperiment used to test if tublin is recycled |
|
Definition
drop temp to 0-4 celcius of sea urchin eggs
once at low temp add protein synthesis inhibitor(puromycin)
then bring the temp up to 15C
because no new tublin is formed and the mitotic spindles reform tublin is recycled |
|
|
Term
| microtubule assembly in vitro |
|
Definition
| temp has to be above 4 celcius, no inhibitors, low CA++, enough GTP, and the critical concentration of tublin |
|
|
Term
| how do you find the critical concentration |
|
Definition
centrifuge sample at 100000
collect supernatn and pellet run it throuhg sds
supernat should have tublin
pellet should have polymers
stain each one and observe when tublin levels off and microtubles form this point is the critical concentration |
|
|
Term
|
Definition
| is how to purify cytoplasmic microtubules |
|
|
Term
| what are the steps of the weisenburg method |
|
Definition
1 homogenize in blender of brains
2 cool to 0-4C(to denature cytoplasmic MT)
3 spin you get pellet1= organelles, mF,iF, membranes
Supernatant1- proteins soluble like tublin and small stuff
4 raise temp of S1 to 37C so the MT repolymerize
5 spin pellet2- pure cytoplasmic MT in this pellet
Supernatant2- proteins including tublin |
|
|
Term
| other things to do with weisenburg |
|
Definition
run P2 through sds you get various tublin
adding high salt to P2 leads to tublin |
|
|
Term
|
Definition
microtubule associated proteins, 2 kinds
1 tau about the same size as tublin
2 high molecular weight
MAPs are ionic interaction with tublin because MAPs are positvely charged a ph7 |
|
|
Term
|
Definition
1 microtubule cross bridging for stability
2 may be regulated by phophorylation
3 may be involved in neurofibrillary tangles seen in alzheimers disease |
|
|
Term
|
Definition
are minus end directed motors,large thing
many kinds of dyneins, all diff sizes
tail region(light chains) are variable amino acid regions= variety of cargo
2 major roles motor for chromosomal movements during mitosis and meiosis
minus end directed transport or retrograde transport inside the cell |
|
|
Term
|
Definition
plus end directed motors, anterogate transport
comprised to 2 heavy chains and 2 light chains
head- the engine atp binds and gets hydrolyzed
stalk- connecting area
tail- where the cargo binds, variable amino acid sequence region
velocity of movement proportional to atp concentration |
|
|
Term
|
Definition
deplete atp levels
low temp(disrupts cytoplasmic MT)
colchicine or other MT drugs
high Ca++(messes with cytoplamic MT)
add functional anti kinesin antibodies(only certain kinds inhibit other anti kinesin do not stop kinesin) |
|
|
Term
|
Definition
can have 3 heads, 2 heads, or 1 head
head=engine |
|
|
Term
| what do axonemal dyneins do |
|
Definition
| they are responsible for axonemal sliding to cause cilia and flagella to bend and beat |
|
|
Term
| what are some differences between cytoplasmic dyneins and axonemal dyneins |
|
Definition
where they are
what they do
what they bind to
amino acid sequence |
|
|
Term
| what is the function of nexin bridges and radial spokes in axonemal dyneins |
|
Definition
| they prevent the axonemal dyneins from sliding too far |
|
|
Term
| what are the 3 different motors on cytoskeletal filaments |
|
Definition
kinesin- plus end directed MT
dynein- minus end directed on MT, cytoplasmic dynein and axonemal dyneins are different
myosin- plus end directed on MF, myosin 1 and myosin 2 are different |
|
|
Term
|
Definition
is globular actin, monomer(subunit) for making MF
only charged actin can add to a growing MF
charged actin only adds to the plus end
ATP hydrolysis is not necessary for MF polymerization
ATP is for recognition to begin binding
actin must be at critical concentrations for polymerization |
|
|
Term
|
Definition
| is fibrous actin it is the MF |
|
|
Term
|
Definition
| the contractile unit of vertebrate muscle |
|
|
Term
| what is the cargo of the sarcomere |
|
Definition
| the thick filaments are the cargo and the thin filaments are the rails |
|
|
Term
|
Definition
| just thing filaments (just actin MFs) |
|
|
Term
|
Definition
| where the thick and thin filaments are seen together |
|
|
Term
|
Definition
| just thick filaments(bipolar myosin filaments) |
|
|
Term
|
Definition
| defines the ends of the sarcomere |
|
|
Term
| what happens when the sarcomere contracts |
|
Definition
1 I band shrinks
2 H zone shrinks
3 thick filaments pull thin filaments towards each other
4 thin filaments (MFs) are attracted to the z-line at their plus ends |
|
|
Term
| what is the rols of Ca++ and tropomyosin in muscle contraction |
|
Definition
| tropomyosin gets in the way of myosin binding to actin. it has to move for myosin to be able to "grab on" to the MF |
|
|
Term
| the actin myosini contractile cycle in vertebrate muscle |
|
Definition
1. ATP binds, causing detachment of myosin. Myosin comes off the MF
2. ATP hydrolysis “energizes” myosin
3. The energized myosin binds to MF
4. Release of Pi causes movement (Power stroke)
5. Release of ADP resets for another cycle |
|
|
Term
| what is unconventioinal myosin |
|
Definition
myosin 1 is one headed, unconventional myosin
usually seen in lamellipodia, growth cone movement, nervous system development, role in phagocytosis |
|
|
Term
| what is conventional myosin |
|
Definition
myosin 2 is two headed
usually found in vertebrate muscle |
|
|
Term
| what is the role of MTs in embryonic development |
|
Definition
MTs help elongate neural ectoderm cells to help from the neural plate
MFs amd myosin 1 help to role up the neural tube, this is required otherwise no nervous system forms |
|
|
Term
| results of griffith experiment |
|
Definition
1 smooth kills- these bacteria can live inside mice lungs and cause pneumonia
2 rough does not kill
3 dead smooth strain does not kill mice
4 trasformation of live rough cells turns them into killers(heat killed smooth cells are mixed with live rough cells) |
|
|
Term
|
Definition
1 protease-mix related extract with rough dead cells and injected into mice will lead to dead mice
2 RNAse is mix treated extract with rough cells and inject them into mice results in dead mice
3 DNAse mix treated extract with rough cells and inject into mice leads to live mice |
|
|
Term
| what was the result of the avery experiment |
|
Definition
| DNAse destroyed the transformation factors so it was DNA that is the transformation factor |
|
|
Term
| what was the hershey chase experiment trying to figure out |
|
Definition
When a virus (phage) infects a bacterium, is the infecting agent DNA or protein?
Is DNA the genetic information that is passed from the infecting virus to all of the progeny (new phages)? |
|
|
Term
| basic idea of virus replication |
|
Definition
| the virus injects dna into the cell, the dna can either be directly replicated by the cell to make virus proteins, or viral rna is recoded into dna by mechanisms in the cell and then production of viral proteins are made. either way the cells create virus stuff by hijacking the cells factories to make more virus |
|
|
Term
| what is metabolic labeling |
|
Definition
| this procedure uses radioactive building blocks to see what is made from those building blocks |
|
|
Term
|
Definition
| marks radioactive sulfur, sulfur is present in amino acids or methionine and ctsteine, proteins inturn have these amino acids, only marks the newly synthesized proteins, and dna does not have sulfur so no radioactivity on DNA |
|
|
Term
|
Definition
| uses radioactive phosphoruous, all DNA has phosphorous, therefore all newly synthesized DNA to be radioactive |
|
|
Term
| what was the procedure for the hershey chase experiment |
|
Definition
1 grow 2 kinds of phages
A) viruses grown in a culture of radioactive sulfur, protein coat is radioactive, dna is not
B) grow viruses in radioactive phosporus, DNA will be radioactive, coat is not
2)make 2 different bacterial cultures
A) infect one group with the culture fof A1 virsues
B) infect the other group with B1 viruses
3) check to see if the new viruses were made in the bacterial hosts and released from the progeny,kids, are radioactive |
|
|
Term
| what was the result of the hershey chase experiment |
|
Definition
| showed that DNA is passed on as the genetic material for viruses |
|
|
Term
| how did hershey chase know that it wasnt rna |
|
Definition
| rna is labeld with radioactive phosphorous, but you could just create 2 culture with one grown with radiactive t(DNA) and the other with radioactive u(RNA) |
|
|
Term
| list 5 things about the nucleus |
|
Definition
1. Defining boundary: Nuclear envelope. It is a double membrane with nuclear pores
2. Support Structures:
Nuclear Lamina (IFs)
Nuclear matrix (scaffolding?)
3. DNA and associated proteins
Chromatin in the nucleoplasm
4. Transcription “machinery”
Transcription in the nucleus
Translation in the cytoplasm
5. Nucleolus
Site of rDNA transcription and ribosomal subunit assembly |
|
|
Term
| describe ribosomal assembly |
|
Definition
1. Small subunit is assembled in the nucleus (nucleolus) from rRNA and rProteins
2. Large subunit is assembled in the nucleus (nucleolus) from different rRNA and rProteins
3. Large and small subunits are exported out of the nucleus to the cytoplasm
4. Functional ribosome is bound to mRNA in cytoplasm for translation |
|
|
Term
| what is produced in the nucleus |
|
Definition
| ribosomal subunits, these subunits are then exported out to the cytoplasm for further use |
|
|
Term
|
Definition
| it is not an organelle, it has no membrane |
|
|
Term
|
Definition
| supports the nuclear pore |
|
|
Term
| in which direction are ribosomes facing |
|
Definition
|
|
Term
| what are nucelar pores made of |
|
Definition
|
|
Term
| what direction do the cytoplasmic filaments face |
|
Definition
|
|
Term
| how do things get through the nuclear pore |
|
Definition
1.Importin joins with a protein that has a Nuclear Localization Signal (NLS protein).
2.This complex binds to nuclear pore cytoplasmic filaments.
3.The complex moves into the nuclear pore and then into the nucleus
4.Importin is brought back into the cytoplasm for another round |
|
|
Term
| why is NLS(nuclear localization signal) important |
|
Definition
for proteins to get into the nucleus NLS is the ticket to get inside
The NLS is part of the amino acid sequence of an NLS protein.
The NLS targets the NLS protein to go to the nucleus |
|
|
Term
| what is the difference between mls and cls |
|
Definition
MLS: Mitochondria localization signal
CLS: Chloroplast localization signal
these are tickets are used to get into chloroplasts or mitochondria |
|
|
Term
| describe the movement of ribosomes throughout the cell |
|
Definition
1. in the nucleus transcription and RNA processing creates rRNA mRNA and tRNA
mRNA and tRNA are sent out of the nucleus into the cytoplasm
rRNA is coded in the nucleus to make ribosomal subunits
2. now in the cytoplasm protein synthesis uses the things made in the nucleus like mRNA,tRNA and ribosomes to produce= ribosomal protins, proteins for replication and proteins for transcription. these items are then shipped back into the nucleus and the cycle begins again to make both the original elements created and DNA replication |
|
|
Term
|
Definition
the portion of the cell cycle between periods of M phase
DNA replication and transcription (gene expression) occur here.
Interphase chromosomes are disperse, nuclear envelope is intact |
|
|
Term
|
Definition
The portion of the cycle where mitosis (nuclear division) and cell division occurs
Little or no DNA transcription and no DNA replication because the DNA is compacted into mitotic chromosomes. No nuclear envelope. |
|
|
Term
| what is disperse chromatin |
|
Definition
Single piece of double-stranded DNA with associated proteins, mostly histones
seen in interphase(46 of these in humans) |
|
|
Term
|
Definition
|
|
Term
| what are Mitotic Chromosome |
|
Definition
paired chromatids
seen in mitosis |
|
|
Term
|
Definition
| Chromatin that remains condensed during interphase. Compacted chromatin. Little or no transcription |
|
|
Term
| what is constitutive heterochromatin |
|
Definition
| Never transcribed. Seen in telomers and centromers |
|
|
Term
|
Definition
| Disperse, transcriptionally active |
|
|
Term
| what regions of DNA are not transcribed |
|
Definition
| telomeric and centromeric regions of DNA are replicated but not translated |
|
|
Term
| what other things do not code for proteins |
|
Definition
The DNA sequences that code for rRNA
The DNA sequences that code for tRNA
Others that we won’t cover in this class (like intron sequences) |
|
|
Term
| How to see euchromatin (actively transcribed chromatin) in a cell |
|
Definition
1.Metabolically label by adding 3H uridine (radioactive uridine). What will this label? Only newly synthesized RNA
2.Autoradiography. Identifying radioactive areas by film exposure |
|
|
Term
| what contributes to a hot spot on the film |
|
Definition
Radioactive uridine incorporation makes new RNA “hot”, this exposes film
This shows where newly made RNA is, in the nucleus |
|
|
Term
|
Definition
a nucleosome is made up of 8 histones
if functions as the particle that wraps the DNA |
|
|
Term
|
Definition
You got 2 domains to each histone core
1 hyrophobic- responsible for histone assembly to make the cor by hydrophobic aggregation
2 hydrophillic- positively charged, hydrophilic faces the water, this attracts dna because the hydrophilic side is positive and dna is hydrophilic and negative charged |
|
|
Term
| what is the role of nuclease |
|
Definition
| digests linker dna, kind like you severed the stings in between the beads so you just have beads |
|
|
Term
| how do you separate dna from its nucleosome |
|
Definition
| dissociation with high salts due to the ionic bonding between dna and the histone |
|
|
Term
| how do you break down the histone |
|
Definition
| run an sds page system to seperate the different histone particles |
|
|
Term
| how do you isolate the nucleus for nuclear matrix preperation |
|
Definition
Homogenize at low speeds
Triton is an uncharge detergent to break membranes and high salt to remove any other lingering charged molecules
Purify the nuclei, detergent extract with triton to remove membranes, add dnase, and rnase, add high salt= nuclear matrix |
|
|
Term
| what is the purpose of the endomembrane system |
|
Definition
Manufacturing and Distribution
Make proteins and lipids and ship them to their appropriate destinations by vesicular trafficking. Also, some recycling done to save energy |
|
|
Term
| what are the main parts of the endomembrane system |
|
Definition
RER (not SER)
Golgi
Transition vesicles
Lysosomes
Plasma Membrane |
|
|
Term
| what are the products of the endomembrane sysstem |
|
Definition
1. Secreted continuously (constitutive)
2. Regulated release
3. Stay inside lumen of ER, golgi or lysosomes
4. Membrane bound, integral protein on any membrane in this system |
|
|
Term
| how do soluble components get into a vesicle |
|
Definition
| soluble cargo attaches to receptors in the vesicle and becomes bound in the vesicle, then |
|
|
Term
| what are some functions of the SER |
|
Definition
Steroid hormone synthesis
Detoxification. Often converting bad hydrophobic (insoluble) compounds into hydrophilic (soluble) ones
Gluconeogenesis. Making glucose from stored glycogen
Ca++ sequestration and regulated Ca++ release
Other functions as well |
|
|
Term
| what are some functions of the RER |
|
Definition
Synthesis of integral membrane proteins
Synthesis of many (not all) soluble proteins, mainly secreted proteins and those destined to stay within the Endomembrane System
Processing (modifications) of newly synthesized proteins that were made by the RER
Membrane biogenesis by synthesis of membrane lipids and membrane proteins
Glycosylation of proteins and lipids |
|
|
Term
| where can you find ribosomes in eukaryotic cells |
|
Definition
Free polysomes (polyribosomes) floating around freely in the cytoplasm
or
Bound to RER-Making proteins to travel in the endomembrane system |
|
|
Term
| what is a nascent peptide |
|
Definition
| Protein in the process of being made but not complete |
|
|
Term
|
Definition
| Protein released from the ribosome |
|
|
Term
| name 2 ways to make proteins in eukaryotes |
|
Definition
1. As soluble proteins in the cytoplasm on free polysomes
A. Some can stay in the cytoplasm (like tubulins, actin, etc.)
B. Some can be targeted to go to organelles with an NLS, MLS, CLS, etc.
2. Cotranslational translocation on RER
A. Integral membrane proteins
B. Proteins destined to stay inside the endomembrane system as either biosynthetic or degredative enzymes
C. Secreted proteins |
|
|
Term
| describe the pulse chase experiment |
|
Definition
1. Add a pulse of radioactive amino acids to growing cells for 3 minutes, then chase with “cold” (not radioactive) amino acids. Only newly made proteins will be “hot”
2. Do autoradiography at different times to see what areas are “hot” (radioactive)
3. Identify organelles by shape and location in cells
4. Express % radioactivity detected by autoradiography as a function of time after the chase |
|
|
Term
| what were the results of the pulse chase experiment |
|
Definition
shows the movement of proteins from RER to golgi and finally to secretory vesicles
we know this becausethat pulse of radioactive amino acids will have a set concentration in the rer and the radioactive will show the movement of proteins throuhgout the cell |
|
|
Term
|
Definition
| It helps to estimate the rates that the proteins leave each compartment |
|
|
Term
| what is differential centrifugation |
|
Definition
Separation based primarily on size and weight
A. Bigger things go into the pellet
B. Smaller things go into supernatant
C. Centrifugation speed (g force) and time determine what goes into pellet and supernatant
D. If two things are similar in density but have different sizes, use this to separate them |
|
|
Term
|
Definition
Separation based primarily on boyant density
A. If two things are similar in size but have different densities, use this to separate them |
|
|
Term
| how do you separate small vesicles microsomes by differential centrifugation |
|
Definition
Homogenize cells to break them open
2. Centrifuge homogenate at low speed
A. Pellet (P1) has big things
B. Supernatant (S1) has microsomes
Centrifuge supernatant (S1) at higher speed
A. Pellet (P2) has microsomes
B. Supernatant (S2) has soluble proteins
but this does not seperate ser from rer because |
|
|
Term
| how would you set up a density gradient centrifugation |
|
Definition
1. Homogenize cells
2. Differential centrifugation to obtain microsome fraction
3. Put microsomes on a density gradient
4. Centrifugation of microsomes on a density gradient separates RER from SER vesicles because RER are more dense than SER |
|
|
Term
| synthesis of soluble proteins in the endomembrane system |
|
Definition
1.If a nascent protein has a signal sequence, it binds to an SRP
2.The SRP-signal sequence complex binds to the SRP receptor, moving the ribosome to the RER
3.Translation resumes with the nascent protein in the translocon
4.Translation continues as the protein is translocated into the lumen of the RER |
|
|
Term
| synthesis of integral membrane protein on RER |
|
Definition
1.If a nascent protein has a signal sequence, it binds to an SRP
2.The SRP-signal sequence complex binds to the SRP receptor, moving the ribosome to the RER
3.Translation resumes with the nascent protein in the translocon
4.Translation continues as the protein is translocated into the lumen of the RER
4. If the nascent protein has a hydrophobic STOP TRANSFER SEQUENCE it will stop further translocation during translation and make it an integral membrane protein.
If it doesn’t have a stop-transfer sequence, it will be a soluble protein instead of an integral membrane protein
5. Some translation may continue until complete
6. The translocon opens, leaving the integral membrane protein stuck in the membrane
Two amino acid sequences are necessary for the synthesis of an integral membrane protein: Signal sequence and stop-transfer sequence |
|
|
Term
| what is the purpose of targeting sequences |
|
Definition
| Specific amino acid sequences target a protein to its appropriate destination. They can be long, short, hydrophobic or at either end. A change in sequence could change the protein’s localization |
|
|
Term
| Do the amino ends of all transmembrane proteins face the lumen of the RER? |
|
Definition
| Not all the amino ends of all transmembrane proteins face the lumen of the rer |
|
|
Term
| describe the orientation of the protein as it is made |
|
Definition
each protein has an amino and carboxyl end
the amino end comes out first and the carboxyl end is the last part to exit the ribosome |
|
|
Term
| describe RER glycoylation summary |
|
Definition
1-2. Start adding carbohydrates to the dolichol carrier on RER. Dolichol is a lipid
3-4. When the core carbohydrates is complete, flip it inside the RER
5. Inside the RER, transfer the core to a protein (or even a lipid)
6. Bud off a vesicle with the glycoprotein in it and send it to its destination |
|
|
Term
| how do you make a glycoprotein or glycolipid |
|
Definition
To make a glycoprotein or glycolipid, the core complex carbohydrates are assembled in the cytoplasm but added to the protein or lipid inside the RER
Sugars are added to dolichol (a lipid) one at a time by specific glycosyltransferases |
|
|
Term
| How do Complex Carbohydrates get on Glycoproteins so that they are facing the Outside of the Cell? |
|
Definition
| They travel through the Endomembrane System and end up on the outside when the transition vesicles turn inside-out |
|
|
Term
| what are the three main parts of the golgi body |
|
Definition
cis- is the closes to the nucleus
medial
trans golgi is the farthest from the nucleus
Golgi sorts proteins to go into vesicles destined for other locations
Proteins move between cis, medial and trans Golgi in transition vesicles |
|
|
Term
| what are some key points about the golgi |
|
Definition
There are many different glycosyltransferase enzymes, each transfers a specific sugar to the complex carbohydrate. Some enzymes take sugars off
Certain glycosylations only take place in the cis-golgi, others only occur in the medial-golgi and others only in the trans-golgi
There are different compartments for different glycosylations |
|
|
Term
| what is Clathrin and what is its role in the movement of transport |
|
Definition
| Moves materials from TGN to lysosomes, endosomes and plant vacuoles. Also from plasma membranes to endosomes |
|
|
Term
| what is the function of COP1 |
|
Definition
| coat proteins for retrograde movement toward RER |
|
|
Term
| what is the function of COP2 |
|
Definition
|
|
Term
| what is the function of VTC |
|
Definition
Vesicular Tubular Clusters (not vesicles)
moves from RER to CGN big blobs of stuff |
|
|
Term
|
Definition
Endoplasmic Reticulum Golgi Intermediate Compartment
the area between CGN and the RER |
|
|
Term
| What do the COP proteins and Clathrin do? |
|
Definition
1. Help to form vesicles by causing membrane curvature and budding
2.Help provide a mechanism for selecting proteins to go into vesicles
3. Help provide a mechanism for vesicle identification so they can go to the right place |
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Term
| what are the steps for transmembrane receptor binding |
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Definition
1.Transmembrane receptor in its native conformation.
COP can’t bind
2.Cargo binds to receptor.
Conformation of receptor changes
now COP can bind |
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Term
| how does Trafficking of soluble proteins in vesicles from RER |
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Definition
1. A transmembrane cargo receptor, facing the lumen of RER, binds specific cargo only inside the RER
2. The other end of the receptor protein, the part facing the cytoplasm, binds a specific coat protein. This labels the outside of the vesicle to tell anything in the cytoplasm what is inside
3. The coat protein can help the membrane to bud off and may help to traffic the vesicle to its appropriate destination |
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Term
| How to sort and retain proteins from Golgi into COPII coated vesicles |
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Definition
1. Soluble proteins (cargo) in the lumen bind to specific transmembrane cargo receptors which face the lumen. This targets them to go into the vesicles.
2. COPII proteins bind to the cytoplasmic part of the cargo receptor
3. The exterior COPII targets the vesicle to move in an anterograde direction |
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Term
| how does Synaptic transmission by regulated vesicular release work |
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Definition
1. Action potential (nerve impulse) travels down axon
2. This stimulates presynaptic Ca++ channels to open
3. Ca++ entry stimulates release of neurotransitter from vesicles
4. Postsynaptic recognition by a receptor triggers response of that cell
some drugs stop neurotransmitter release other block reuptake |
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Term
| what is the difference between V-snare and T-snares |
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Definition
V-SNARE: Protein on vesicle
T-SNARE: Protein on the target membrane |
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Term
| what kinds of bonding are necessary for vesicle fusion |
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Definition
Many different kinds of bonding are necessary for vesicle fusion.
For some kinds, like this one, ionic bonds are important
to test you could add high salt to see if that disrupts the ionic bonds break |
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