Cell Bio III Flashcards
1
Q
Macropinocytosis
A
- Actin-based
- Nonspecific ingestion of fluid and solutes
- Can be triggered by bacteria
2
Q
Clathrin-mediated endocytosis
A
- Occurs at clathrin-coated pits
- Dynamin GTPase required to pinch off vesivle.
- Can be mediated by receptors - process to endocytose specific molecules
3
Q
Phagocytosis
A
- Ingestion of large particles, mediated by receptors
- Dependent on actin, not clathrin
- Phagosomes fuse with lysosomes
4
Q
Regulated pathway of exocytosis
A
stores product
5
Q
Constitutive pathways of exocytosis
A
constantly forms secretory products to go through exocytosis. Does not store
6
Q
Porocytosis
A
Quantal release of neurotransports
7
Q
Ribosomes
A
- Contain E, P, and A sites
- Have large and small ribosomal subunit
- Required for protein synthesis
8
Q
rER
A
- Cisternae are studded with polyribosomes
- Basophilic
- Continuous with outer membrane of nuclear envelop
9
Q
Function of rER
A
- Synthesis of proteins for secretion, insertion into membranes, and lysosomal proteins
- Synthesis of sER enzymes
- Protein modification - cells with a lot of protein syntheiss have a lot of rER
10
Q
Glycosylation
A
Attaches one carbohydrate to another, helps with protein folding
11
Q
ER stress
A
Accumulation of unfolded/misfolded proteins in the ER cisternia
12
Q
Unfolded protein response
A
- Increased chaperone synthesis to help repair misfolded proteins
- Decreased synthesis of proteins
- Misfolded proteins get exported from ER to cytosol where they are tagged for degradation by proteasomes
- Activate caspases - apoptosis
13
Q
Alpha1-antitrypsin deficieny
A
mutant protein aggregates in ER
14
Q
Function of sER
A
- Steriod synthesis
- Cholesterol homeostasis
- Synthesis of phospholipids
- Glycogen metabolism
- Drug detox
- Storagem release, and uptake of calcium ions in striated muscle
15
Q
Von Gierke’s disease
A
- Glycogen storage disease
- Mutation at either g-6-p transporter or glucose-6-phosphatase
16
Q
What can increase the volume of sER
A
phenonbarB, in alcoholics
17
Q
Co-translational translocation of proteins
A
- Have mRNA bound in ribosome. Also bound is protein strand with a recognition strand
- Signal recognition molecule sees recognition strand then binds
- Whole complex binds to signal recognition receptor
- Translocon gets “uncorked”
- Protein sequence can enter lumen of rER
- After protein sequence enters, signal peptidase cleaves off signal sequence, releases mature protein into rER lumen
