B: Endocytosis, Autophagy, Cytoskeleton (21) Flashcards
What does COP stand for
COat Protein complex = COP
What is the purpose of the COT
Help with the traffic between the ER and golgi
Coat proteins that help to form transport vesicles, select cargo, and direct them to a target compartment
How do coatamer proteins work
Works by recognizing transmembrane protein, binding with them and making vesicle that moves in that direction
COP released once vesicle made
What is the AP complex
Adaptor protein complex
What are adaptor proteins and calathrin
2 types of coatamers
What is the role of Calathrin and AP
AP/Clathrin -coated vesicles move from TGN (trans-golgi network) to other vessicomes (lysosomes, endosomes, ect)
Where does catherin move vesicles
Catherin moves golgi to late endosome
What are the 2 key functions of lysosomes
- Autophagy
- Degradation of internalized material
Where does the AP complex move vesicles
AP complex moves golgi to plasma membrane
What is autophagy
Autophagy: normal disassembly of unnecessary of dysfunctional cellular components - organelle turn over
Explain how lysomes help the degredation of internalized material
Recycling of plasma membrane components like receptors and extracellular materials
Destroy pathogens like bacteria and viruses - only in phagocytic cells
Explain the structure of plant vacoules
Vacuoles are fluid-filled, membrane bound
They can take up about 90% of plant cells
What are the function of plant vacoules
- Intracellular digestion
- Mechanical support
- Storage
Explain intracellular digestion in plant vacoules
- Comparable to lysosomes in animal cells
- acid hydrolisis
Explain mechanical support in plant vacoules
Supports soft tissue
Stretches cell wall during growth
Explain storage in plant vacoules
Chemical storage of toxic compounds and pigments
What is the cytoskeleton
Dynamic network of interconnected filaments and tubes that extend through cytosol (and some organelles) of eukaryotes
What are the 4 functions of the cytoskeleton
- Structural support
- Spacial organization within cell
- Intracellular transport
- Contractility and motility
What are the 3 components of cytoskeletons
Microtubules - highway (25 nm)
Intermediate filaments - exits (10 nm)
Microfilament - roads (7-9 nm)
What are microtubules made of (in the cytoskeleton)
Polymer of 2 different proteins (monomers): alpha and beta tubulin
What are the 2 major types of microtubules (in the cytoskeleton)
- Axonemal MT
- Cytoplasmic MT
What are the charges on microtubules, how does it affect function?
Negatively charged end connected to centrosome
Positive end can expand and contract rapidly
What is the structure of microtubules
- Alpha/beta heterodimers form long protofilaments
- 13 protofilaments form longitudinal array creating hollow cylinder
What is the role of the MTOC
Microtubule-organizing center (MTOC) is a central site of MT assembly
What does MAPs stand for
Microtubule-associated proteins
- Several different proteins that bind MTs
What are the 2 classes of MAPs
- Non-motar MAPS
- Motar MAPS
What is the role of non-motar maps
Control MP organization in cholesterol
What are the role of motar MAPS
Use ATP to generate force
Can move material along MT track
Can generate sliding forces between MTs
