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56 Cards in this Set
- Front
- Back
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... or ... is the mechanism by which a cell transports proteins to the appropriate positions within the cell or outside of it (secretion).
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protein targeting
protein sorting |
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typical mammalian cells contain up to # different kinds of proteins
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10,000
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protein targeting is guided by ... within the polypeptide chain itself
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targeting signals
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A short amino acid sequence at the N-terminal end of a polypeptide chain that acts as a postal code for the target organelle is called a ...
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signal peptide
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separate portions of the peptide chain that are brought together when the protein folds and act to target proteins to specific cellular locations is called ...
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signal patch
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what kind of ribosomes make proteins that are destined to go to the nucleus, mitochondria, chloroplasts, and peroxisomes?
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free ribosomes in cytosol
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what kind of ribosomes make proteins that are destined to go to the plasma membrane, secretory vesicles, and lysosomes?
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membrane bound ribosomes
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exocytosis involves what type of transport?
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anterograde transport
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what are the 2 types of secretory pathways?
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constitutive
regulated |
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Resident enzymes are differentially distributed across the golgi stacks. For example, sialyltransferase is only located in the ... golgi
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trans
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the forming face of the golgi is the ... face
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cis
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the maturing face of the golgi is the ... face
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trans
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the golgi is polarized: The ... or entry side faces the rough ER; the ... or exit side faces secretory granules or vesicles and centrioles
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cis
trans |
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the golgi is exclusively responsible for a number of ... of proteins
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post-translational modifications
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the cell is divided into many ..., usually membrane bound, which possess different functions.
These functions relate to functions of the organism at the gross level |
compartments
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The process of membrane trafficking begins with the transport of material from the ... to the ...
This is performed by the budding off of membrane-bound vesicles called ... vesicles |
rER
Golgi transport |
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during the membrane trafficking process, membrane components and materials in the lumen of these vesicles are transported to a ... of an organelle, or in this case from one organelle to another
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new region
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The vesicles formed from the rER are coated on the cytoplasmic side of the membrane by ... protein.
This protein helps transport the vesicle into the proper spot from the rER to the golgi. |
COPII
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The membranes of the transport vesicles lose their coat and fuse with the membranes of the ... of the golgi
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cis-face
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The transported material and membranes are then further transported through other stacks of the golgi by a similar process of ... and ...
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budding
fusion |
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along the way the cargo proteins are modified by various ... found within the different stacks of the golgi
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enzymes
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Terminal N- and O-glycosylation and phosphorylation of lysosomal enzymes occur on the ... face of the golgi network
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cis
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The different stacks of cisternae in the golgi can be identified by ... techniques
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cytochemical
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The cis-most cisternae contain a higher content of lipid in their membranes and thus can be identified by ...
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osmium tetroxide reduction
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the middle and trans-side cisternae contain a higher content of ... enzymes and can be identified by reactions for these enzymes activities.
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glycosylation
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the trans-most cisternae (trans golgi network) is the site where ... are produced and contain ... marker activities
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lysosomes
lysosomal |
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The golgi is the major center for trafficking of what 3 things?
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membrane proteins
secretory proteins lysosomes |
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along with this forward transport of membrane and luminal components, there is also a ... transport between the golgi stacks and the rER.
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retrograde
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This retrograde transport from the golgi to the rER involves an ER receptor and a coating protein called ...
Thus, the golgi is also the source of mature proteins for the rER |
COPI
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From the golgi, proteins are delivered to the membrane, either as ... proteins, ... proteins, or to the ... compartment
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integral membrane
secretory lysosome |
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... cells (aka exocrine cells) sort products into storage vesicles in the trans Golgi network.
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secretory
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There are 2 types of secretory proteins.
Which type of secretion is direct to the surface and is constantly going on? Which type of secretion requires secretory granules (storage vesicles) and has something controlling its release? |
Constitutive
regulated |
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which type of secretion is
-continuous and unregulated -directly to the cell membrane for immediate exocytosis -in all cells it is a default pathway that carrier whatever is left over after other products are sorged to specific locations |
constitutive secretion
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In constitutive secretion, the glucose transporter and blood proteins go to the ... membrane domain.
the basil lamina components go to the ... domain. |
apical
basolateral |
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regulated secretion is triggered by an external signal or ... (usually involved in the release)
proteins are packaged into ... coated transport vesicles These vesicles fuse to form ... vesicles |
hormone
clathrin condensing |
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In regulated secretion, vesicles emptied of their content return in transport vesicles to the ...
This concentrates the secretory content and maintains the amount of membrane in the ... |
Golgi
Golgi |
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which type of secretion can get a big surge in what is being released in response to a hormone?
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regulated secretion
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what type of cell is this?
-Cholocystokinin triggers zymogen secretion -30X cell area added by vesicles in minutes -must be same area removed by endocytosis |
pancreatic acinar cell
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Following fusion with the plasma membrane, the integral membrane proteins in the lipid bilayer of the secretory ... (released by constitutive) and ... (released by regulated pathway) are inserted into the plasma membrane of the cell
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vesicles
granules |
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glycosylation:
N-linked (NH2 on ...) glycosylation |
asparagine
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Sorting of hydrolytic enzymes into lysosomes:
-All lysosomal enzymes are ... glycoproteins -phosphotransferase in the ... golgi compartment recognizes acid hydrolases -It phosphorylates ... on mannose position 6 (mannose 6 phosphate or M6P) |
N linked
cis oligosaccharide |
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... is the routing signal for lysosomes
Lysosomal proteins are transported to primary lysosomes by a ... receptor system. This transport occurs at the ... golgi network |
M6P
M6P trans |
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phosphate is attached to mannose 6 in the CGN by ...
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phosphotransferase
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what disease is this?
-caused by a deficiency of the ability to phosphorylate mannose -characterized by skeletal abnormalities, restricted joint movement, coarse facial features, and severe psychomotor impairment -death usually occurs by age 8. |
I-cell disease
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lysosomes contain ... (more than 40 identified) and are (less/more) acidic than the cytoplasm
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acid hydrolases
more |
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lysosomes are ... membrane-bound organelles (.05-.5 micrometers diameter)
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single
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the 2 subcategories of lysosomes are ...
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primary lysosomes
secondary lysosomes |
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which subcategory of lysosome is this?
-0.2 - 2 micrometer diameter -digestion has began -contains heterogeneous material in matrix (substances being digested) |
secondary lysosomes
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which subcategory of lysosome is this?
-0.05-.3 micrometer diameter vesicle with dark matrix -located near golgi complex -contains hydrolytic enzymes but has not yet began digestive process |
primary lysosomes
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what are these?
-large vacuoles containing undigested (undigestible) material -become lipofuscin (undigested material) or age pigments which accumulate in certain cells |
residual bodies
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the enzymes contained in lysosomes are capable of breaking down most biological ... into molecules useful to the cell.
these enzymes include acid phosphatases, ribonucleases, deoxyribonucleases, cathepsins, sulfatases, lipases, beta glucuronidase, etc. |
macromolecules
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Another function of lysosomes is ... of extracellular substances, intracellular organelles (autophagy).
Enzymes can be released by ... lysosomes into the extracellular space (e.g. osteoclast-to break down bones) |
digestion
primary |
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lysosomal enzymes and lysosomal membrane proteins are transported to primary lysosomes by a ... receptor system
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mannose-6-phosphate
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several highly glycosylated ... glycoproteins have been identified in lysosomes which have been found to be resistant to degredation by lysosomal enzymes.
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integral membrane
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An example of an integral protein that is resistant to degredation by lysosomal enzymes is an ..., which is believed to be responsible for the maintenance of the pH < 5 found in the lumen of the lysosome.
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ATP-driven proton pump
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what are these?
-defects in genes that code specific enzymes -molecules to be degraded build up and are stored in lysosomes -some organs affected more than others -most often kidney, liver and brain -symptoms mild to death -I cell disease: defect in M6P phosphotransferase - enzymes secreted |
lysosomal storage diseases
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