Endomembrane Transport + Cytoskeleton Flashcards
What are cytoskeletal filaments made out of?
Protein
Actin filaments
Smallest filament
Maintain cell tension by resisting pull
Used for muscle contractions and cytokinesis
Moves organelles
What does actin interact with?
Myosin
To facilitate movement
What does myosin do?
Hydrolizes ATP to walk along actin
Intermediate filaments
Thicker than actin and can resist more pull
Anchor nucleus and other organelles
Microtubules
Largest in diameter and make hollow tube
Resist compression
Move cells via flagella or cilia
Move chromosomes during cell division
Provide tracks for intracellular vesicle transport
Kinesin
motor protein that helps vesicles move along microtubule track
Cili and flagellum
made up of microtubules
roughly the same size
Primary cilia
Abreu’s line of work
Single cilia that pops up and receives sensory information
Nuclear envelope
nuclear pore complex allows mRNA and ribosomes out
allows nucleotides and proteins in
Where does the endomembrane transport system start?
The rough ER
Where do the ribosomes that stud the rough ER come from?
They were free floating ribosomes, but then a protein coded for them to attach to the ER since they were producing a protein designated for secretion
Signal recognition particle (SRP)
ER signal sequence binds to the SRP, which then binds to the rough ER membrane
Cis- cisterna
front side of the golgi
faces the rough ER
Trans- cisterna
back side of the golgi
produces vesicles
Glycosylation
carbohydrates are attached to proteins through a covalent bond in golgi
this identifies proteins and tells them where to go
Mannose-6 phosphate
a sugar tag that specifically sends things to lysosome
What do the sugar phosphate tags work with?
Receptors on golgi vesicle’s membrane
Endosome
a vesicle that the cell uses to engulf macromolecules to take them into the cell
Reasons for endocytosis
need materials
need to break down a harmful substance
What happens to the endosome once in the cell? Why?
Endocytic vesicle fuses with the endosome and lowers the endosome’s pH
this is because the lysosomes have a low pH
Where are endosomes transported to?
The lysosomes so it can break them down
Autophagy
old organelles are broken down by lysosome
Phagocytosis
engulf an entire prokaryotic cell
