M1 L5 Endomembrane system and Bulk transport Flashcards
Define what is meant by the endomembrane system. • Describe the function of the components of the endomembrane system . • Outline the bulk transport processes of endocytosis (phagocytosis, pinocytosis, receptormediated endocytosis) and exocytosis (constitutive and regulated). • Outline the role of the lysosome.
Endomembrane system
- Several different organells that are membrane bound, located inside the plasma membrane.
- nuclearenvelope
- endoplasmic reticulumn
- glogi apparatus
- vescile
- lysosomes
- vacuoles
- plasma membrane
Endoplasmic reticulumn
- rough and smooth ER
- flattened sack with stacked continues with nuclear envelope.
rER
- has ribosomes which gives rER rough surface
- protein is synthasised here (mainly for exocytosis)
- some Protein stay, some are excreted and some will become membrane bound membrane.
Lumen is the interiror of the rER. –> the proteins enter lumen —> they get preocessed in rER
Smooth ER
- has no ribosome
- metabolise carbohydrates
- synthasis lipids for memrane
- storage of calcium ions
signals and for chnages in the cells - detoxifying of blood and hipotocyte.
- can exists in larger quantities which depends on the needs of the cell.
Golgi complex structure
- series of sacs wit associated vasicle.
- cis arrival and trans leaving site
Lysosome (only in animals)
- Degrades proteins, lipids, carbohydrates, nucleic acid.
Golgi complex functions
- Glycosylation
- sorting proteins
- directing proteins
- other functions
Glycosylation at Golgi
- add or modify carbohydrates on protein
- important for cell recognition proteinss
sorting proteins at golgi proteins
- molecular proteins have markers attached to them
- directs proteins to the correct vesicle for transporatation.
directing vescile at Golgi
- molecular tags added to vascile to direct them to target.
- markers and tags are short proteins on vesicle surface.
cellular structure - eukaryotes
cytoskeleton
cilia or flagella
centrasome
Cytoskeleton
Made up of microtubules, microfilaments, intermediate filament
maintains cell shape,
direct movements or organells, transmit signals
dynamic - not static
cilia and flagella
helps with motality
centrosme
important for DNA replication, mitosis and meiosis
Moving back to cells –> cellular functions
exocytosis endocytosis pino cytosis receptor mediated endocytosis endosome lysosome pathway