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stacks of flattened cisternae lacking ribosomes
The ______ face of the Golgi faces the ER
The _______ face is on the opposite end of the stack
Golgi networks are processing and sorting stations where proteins are....NAME 2 FUNCTIONS
Modified with various molecular additions or subtractions.
Segregated and then shipped in different directions using signals receptors and cytoskeletal elements.
THE CIS SIDE FACES WHAT?
NAME THE 5 LEVELS OF THE GLOGI
Sorts proteins for the ER or the next Golgi station
- Cis Golgi network (CGN)
- THE LOWER REGION
Sorts proteins to various cellular destinations
- Trans Golgi network (TGN)
- THE UPPER REGION
reduced osmium tetroxide...WHERE CAN IT BE FOUND?
reduced osmium tetroxide in cis cisternae
enzyme mannosidase II IS WHERE IN THE GC?
enzyme nucleoside diphosphatase WHERE IN THE GC?
trans region only
Oligosaccharides attach to ________ & ______ in the Golgi
glycoproteins and glycolipids
Synthesis of complex _________ takes place in the Golgi
Glycosylation in the Golgi Complex. HOW MANY STEP AND HOW LONG AT EACH REGION?
Vesicular transport within the Golgi complex: Two views..NAME THEM
- Vesicular Transport. OUTSIDE EDGES BOTH UP & DOWN.anterograde movement of vesicles cis to trans.
- Rothman Stanford, 1983.
Cisternal Maturation. THRU CNTR OUT AND OUTSIDE TOWARDS CIS. 1990s
WHAT IS THE Cisternal Maturation model
A more recent version of an older model holds that cisternae formed on the cis face are transient and physically move to the trans face; 1990s data shows retrograde trans to cis movement of vesicles i.e. backwards.
WHAT IS THE Vesicular Transport model?
Material moves through permanent Golgi stacks in the vesicles; James Rothman, et al. (Stanford, 1983) showed anterograde movement of vesicles cis to trans
DEFINE vesicular (retrograde) and cisteral (anterograde) movement. WHAT MODEL DOES IT COENSIDE WITH?
- vesicular (retrograde)...BACKWARDS
- cisteral (anterograde)...FORWARDS
- cisternal maturation model.
Materials carried between membrane compartments by membrane-bound vesicles. SIZE
typically 50 - 75 nm dia
T OR F ?
Most budding vesicles covered on cytosolic surface by fuzzy, electron-dense layer.
TRUE. REMEBER THAT PROTEINS ARE PART OF THE MIX
Protein coats have at least two distinct functions, NAME THEM.
- They act as a mechanical device that causes the membrane to curve & form a budding vesicle.
- They provide a mechanism for selecting components (& thus soluble cargo) to be carried by vesicle
COPI & COPII, WHAT THE HELL ARE THEY AND WHAT DO THEY DO?
- PROTEIN COATS.
- COP II GOES FROM RER TO GC
- COP I FROM GC TO RER
WHICH WAY DOES THE COP1 & COPII TRAVEL?
DOES THE COPI AND COPII LEAVE THE GC?
- CLATHRIN TAKES IT FROM THE TRANS FACE OF THE GC.
Components selected for transport can include WHAT? NAME 3
secretory, lysosomal, & membrane proteins.
Binding of SarI-GTP to ER membrane initiates assembly...OF WHAT?
- COPII subunits to form vesicle coat.
COPII subunits to form vesicle coat, WHEN THIS IS OCCURING THE CARGO PROTEINS OF ER LUMEN BIND TO LUMINAL ENDS OF ______ CARGO RECEPTORS.
WHAT 2 UNITS BIND TO THE ER MEMBRANE INITIATES THE ASSEMBLY OF COPII SUBUNITS THAT FORM A VESICLE COAT?
- Binding of SarI-GTP
___________ & its derivatives __________ can recruit particular proteins to specific sites on membrane surfaces during membrane trafficking
Phosphatidylinositol & (phosphoinositides)
the protein dynamin is recruited to clathrin-coated vesicles, in part, by the presence OF WHAT? WHAT IS THIS A GOOD EXAMPLE OF?
the presence of the phospholipid PI(4,5)P2 in the membrane at budding sites.
THIS IS A GOOD EXAMPLE OF MEMBRANE BEING USED FOR TRAFFICKING & CONCENTRATIONS.
A lipid species like PI(4,5)P2 can have a dynamic regulatory role because it can be rapidly formed & destroyed by enzymes that are localized at particular places & times within the cell.
protein dynamin...WHAT DO YOU THINK OF?
Distinct classes of coated vesicles...NAME 3
COPII, COPI, and Clatherin
DEFINE COPII-coated vesicles
Move materials forward from ER to ERGIC (intermediate compartment between ER & Golgi) & Golgi complex; COP is acronym for coat proteins
COP is acronym for _____ ______.
COPI IS ASSOCIATED WITH WHAT MOVEMENT?
- RETOGRADE. ON THE SIDE.
- ERGIC & Golgi stack backward toward ER
Also thought to transport materials through Golgi from TRANS to CIS face
ENZYME PATHWAY THAT BREAK DOWN THINGS.
Resident proteins of ER have _____________used to retrieve them from Golgi if accidentally sent
C terminous aa sequences
Resident proteins of ER have C terminous aa sequences used to retrieve them from Golgi if accidentally sent..NAME 2
- Soluble ER proteins have KDEL retrieval signal.
- KDEL receptors in cis Golgi compartment “lys-asp-glu-leu”
ER membrane proteins have KKXX signal “lys-lys-x-x” Bind to proteins of COPI-coat
KDEL receptors in Golgi compartment.
WHAT REGION OF THE GOLGI?
WHAT IS THE AA SEQUENCE?
- CIS REGION
KDEL & KKXX RETRIEVAL SIGNALS.
WHICH ONE IS SOLUBILE?
WHICH ONE IS ASSOCIATE WITH MEMEBRANES & COPI COATS?
KKXX..MEMBRANE PROTEINS. BINDS TO PROTEINS OF COPI COAT.
IF KDEL OR KKXX IS ACTIVACTED, WHERE DOES IT GO?
BACK TO THE ER.
GROUP OF SUGARS
DEFINE Clathrin-coated vesicles
- Move materials from TGN to endosomes, lysosomes & plant vacuoles
- Also move materials from plasma membrane to cytoplasmic compartments along endocytic pathway
- Also implicated in trafficking from endosomes & lysosomes
WHEN DEALING WITH LYSOSOME DESTINATIONS, WHAT IS THE MAIN RECEPTOR?
Targeting lysosomal enzymes to lysosomes.. NAME THE 6 STEPS
- 1.Phosphorylation of mannose in Golgi.
- 2. Moved to clatherin-coated vesicle in TGN.
- 3. Interact with cytosolic adapters in vesicle.
- 4. Mannose-6-P receptors separate from enzymes, Enzymes move to endosome and then to lysosome.
- 5. Return to Golgi.
- 6. Secreted extracellular lysosomal enzymes can be captured and retrieved and directed to endosome.
WHERE DOES THE PHOSPHORYLATION OF LYSOSOMAL ENZYMES OCCUR IN THE GC?
- CIS GOLGI CISTERNA
WHERE DOES THE FORMATION OF THE CLATHERIN COATED VESICLES OCCUR?
SO HOW DOES A TRANSPORT VESICLE KNOW WHERE TO GO AND BIND TO?
- a) Rab proteins on vesicle target membrane recruit tethering proteins for initial contact with target membrane.
- b) Docking and fusion involve various SNARE proteins where helixes interact to allow fusion.
WHAT IS THE FUNCTION OF "SNAREs"
- membrane fusion and exocytosis.
NAME 3 TYPES OF SNAREs
- Syntaxin (red)synaptobrevin (blue)SNAP-25 (green)
- contain acid hydrolases that can digest every kind of biological molecule.
- Internal proton concentration is kept high by H+-ATPases
WHAT IS THE INTERNAL PROTON CONCENTRATION IN LYSOSOMES?
Internal proton concentration is kept high by H+-ATPases. PROTON PUMPS
HOW DOES A LYSOSOME PROTECT ITSELF FROM SELF DIGESTION?
- Glycosilated(SUGAR COATED) proteins,
- Igp-A and Igp-B, may protect the lysosome from self digestion
WHAT ENZYME IS USED TO ID LYSOSOMES?
THE LYSOSOMAL ENZYME B-GALACTOSIDASE BREAKS DOWN WHAT SUBSTRATE?
WHAT LYSOSOMAL ENZYME BREAK DOWN DNA/RNA?
- RNA...ACID RIBONUCLEASE
- DNA...ACID DEOXYRIBONUCLEASE
Lysosomes are involved in two major cell functions..NAME THEM
DEFINE lipofuscin granules
IT'S A GRANULE THAT THE LYSOSOME CANT BRAEK DOWN. LIKE WHEN IT TRIES TO AUTOPHAGE A MITOCHONDRIA AND CANT BREAK IT DOWN COMPLETELY.
WHERE DOES THE FORMATION OF THE AUTOPHAGIC VACUOLE OCCUR?
Disorders from Lysosomal Defects...NAME 3
- lysosomal uptake of indigestible fibers.
- (Silicosis and asbestosis)
Lysosomal storage disorders result from the absence of specific lysosomal enzymes.
THE DAMN THING BREAKS OPEN & FUCKS UP THE CELL & THE SURROUNDINGS
TAY-SACKS IS CAUSED BY WHAT?
lack of hydrolytic enzyme for ganglioside GM2 & deficiency of the enzyme N-hexosaminidase A
leads to accumulation of undigested glycolipids and mental retardation, no degradation of gangliosides in the brain.
NAME 2 WAYS THAT YOU CAN GET RIDE OF A PROTEIN IN A CELL.
LYSOSOMES & PROTEASOMES
- Degrade individual cellular proteins that are no longer needed.
- Proteins have characteristic longevity, correlated to its function.
LYSOSOMES IN ANIMAL ARE LIKE ____ IN PLANTS.
A TONOPLAST HAS 3 FUNCTIONS
- TRANSPORT INTO VACULE
- TURGER PRESSURE
NAME THE OPSONINS THAT MAY STIMULATE PHAGOCYTOSIS.
MAKES SOMETHING THE CELL WOULD CONSUME MORE PALETABLE TO EAT.
ANOTHER NAME OF CELLULAR UPTAKE IS...
Phagocytosis is the cellular uptake of particulates.
WHAT IS THE DIFFERENCE BETWEEN PHAGOCYTOSIS & ENDOCYTOSIS?
- PHAGO: Particles and macromolecules.
- ENDO: material dissolved or suspended in fluid
the cellular uptake of material dissolved or suspended in fluid
2 TYPE OF ENDOCYTOSIS ARE.....
Bulk phase endocytosis does not require surface membrane recognition.
Receptor mediated endocytosis (RME) follows binding of substance to membrane receptors
Involves clatherin coat and complete vesicle formation and removal from the plasma membrane...WHAT PROCESS IS THIS?
T OR F?
CLATHERIN IS INVOLVED IN BOTH ENDOCYTOSIS & ENDOCYTOSIS
DEFINE Ligand bound receptors
Collect in specialized regions of the membrane forming coated pits. EXTERIOR (OUTSIDE) OF CELL.
DEFINE CLATHERIN STRUCTURES
- Contains three chains that form a triskelion
- Can change from a flat sheet to a cage like scaffold surrounding the vesicle.
- The formation of clatherin-coated endocytic vesicle requires an additional GTP-binding protein
WHAT HOLD A PLASMA MEMBRANE COMPOSED OF CLATHRIN TOGTHER?
- ADAPTOR PROTEIN (AP2) COMPLEX
THE 3 ENDS OR "HOOT" OF A TRISKELION , WHAT TERMINAL END OF THE CLATHRIN HEAVY CHAIN IS IT?
WHAT IS THE FUNCTION OF DYNAMIN IN REGURDS TO CLATHRIN PLASMA MEMBRANE PROCESS?
DEFINE THE ENDOCYTIC PATHWAY
- 2 PARTS EARLY AND LATE ENDOSOME!
ENDOCYTIC PATHWAY...NAME THE PHASE AND WHAT HAPPENS IN EACH.
early and late endosomes.
- Materials in early endosomes are sorted and integral membrane proteins are shipped back to the membrane.
- Molecules that reach the late endosomes are moved to lysosomes,which include other dissolved materials and bound ligands.
______ is associated with lowering cholesterol levels.GOOD.
_______are associated with high blood cholesterol. Formation of atherosclerosis. BAD.
IN CELLULAR UPTAKE, WHAT IS THE FUNCTION OF THE ENDOSOMES?
THEY ARE THE CONTAINERS FOR WHAT JUST CAME INTO THE CELL. THEY DONT BREAK DOWN, THATS THE LYSOMES FUNCTION.
Cholesterol is transported by the blood in ________complexes
LDLs are taken up by _______ and delivered to lysosomesReleases the cholesterol for use by cells
RECIEPTOR MEDIATED ENDOCYTOSIS (RME)
HDLs transport _______
From tissue to the liver.
OF THE TWO TYPES OF CHOLESTEROL, WITH ONE IS INVOLED WITH RME?
- LDLs are taken up by RME and delivered to lysosomes.
- Releases the cholesterol for use by cells
T OR F?
HORMONES ARE MADE BY LDL IN THE CELL.
T OR F?
HDL TRANSPORT CHOLESTEROL THRU BODY REGIONS
Formation of atherosclerosis...HIGH LEVELS OR HDL OR LDL?
WHAT THE HELL IS ESTERIFIED CHOLESTEROL?
- CHOLESTEROL PACKAGED FOR TRANSPORT
atherosclerosis plaque formation....WHAT ARE THE 4 STEPS?
WHERE IN THE FUCK DID YOU HEAR THE TERM"FOAM CELL"
atherosclerosis plaque formation..FORMS IN THE ENDOTHELIAL INJURY SITE WHERE LDL FORM A CLOT.
WHEN A PROTEIN IS MADE IN THE CYTOSOL, HOW IN THE HELL ODES IT GET INTO THE MITOCHONDRIA?
- CHAPERONES BRING IT TO THE OUTER MEMBRANE, THEY GET TRANSPORTED THRU THE TOM/TIM COMPLEXES INTO THE MITOCHONDRIA MATRIX.
- POS CHARGE OF PROTEIN FIRST THRU PORES
NAME TWO CHAPERONE THAT ARE INVOLED IN TRANSPORTING PROTEINS TO THE MITOCHONDRIA MADE IN THE CYTOSOL.
- CYTOSOLIC CHAPERONE Hsp70
- MITOCHONDRIA CHAPERONE: mtHsp70
HOW MANY STEPS ARE THEIR TO TRANSPORT A PROTEIN PRODUCED IN THE CYTOSOL THAT NEEDS TO GOTO THE MITOCHONDRIA?