Cellular Compartments and protein sorting Flashcards
many organelles are bound by how many membranes?
One membrane such as vesicles, peroxisomes and lysosomes
What are vesicles in?
Vesicles - protein transport, exocytosis, golgi to and from ER
What are peroxisomes involved in?
Fatty acid breakdown
Phospholipid synthesis
Pentose PO4 pathway
What are lysosomes involved in?
Breakdown of proteins, nucelic acids, cell debris, carbs, lipids
Signalling
Membrane repair
Which organelles are topologically equivalent with the extracellular space?
Endosome, lysosome, Peroxisome, Golgi, ER
What are the 2 ways in which molecules can pass from vesicle to vesicle to EC space?
Molecules can pass directly between cisterna in Golgi and can pass across the cell via vesicles
One organelle can transform into another via what?
By vesicle budding and fusion
when a vesicle moves from the outside of the cell to the inside or vice versa. Is the organelle lumen topologically equivalent to the extracellular space?
Yes,
The inner face and outer face of an organelle can be referred to as what in comparison to the cytosol?
The inner face is non cytosolic
Outer face is cytosolic
What organelles have 2 membranes?
Nucleus, mitochondria and chloroplast
Interior of nucelus is equivalent to what and continuous with what?
Cytosol
what explains why nucleus and cytosol are equivalent?
Evolution, membrane bound ribosomes in ancient procaryotic cell moves inwards and pulls the membrane in which causes an ER to form around the DNA.
How did mitochondria and chloroplasts evolve?
By engulfment of prokaryotic cells, endosymbiosis theory
Where do all proteins begin synthesis?
On free ribosomes in cytosol
What are the 3 mechanisms for getting access to compartments and describe whether or not the areas are topologically equivalent?
1) Gated transport, movement between cytosol and nucleus (topologically equivalent)
2) Transmembrane transport between mitochondria, plastids and peroxisomes and ER, (Not topologically equivalent) so it uses protein translocators
3) Vesicular transport between ER and other organelles plus cell surface (topologically equivalent)
