lecture 10 endocytosis

CELB30090

What is endocytosis

the process in which cells engulf large molecules like pathogens and bacteria

what are Pis

these are lipids that are used as identity to different membrane n the cell allowingfor the bindin of different proteins

what is Phagocytosis

• the breakdown of large particles like bacteria

what is the macriounicytosis pathway

Internalisation of large amounts of fluids and growth factors

what is clathrin dependent endocytosis pathway

Interalisation of receptors and extra cellular molecules

what is caveoline dependent endicytosis pathway

Internalisation of specific lipid associated molecules

what is caveolin and calathrin indpenedent pathway

Membrane internalisation and small fluids

what process drives phagocytosis

Actin cytoskeleton

what is a pseudopod

A pseudopod membrane is a membrane that extends outward to engulf large particles driven by gtpase RHO family ( rac and cdc42)

what are the family GTPaes invovled in phagocytosis and what od they stimulate

RHO, RAC, cdc45 - stimulates nuculation and polymerisation

exaplin the steps invovled in phagocytosis

a. Receptors of pseudopod membrane recognise

b.Receptors active RHO family stimulate @ulceration and polymersations

c.A'ctin is depolymerised at the base of this cup due to a local change in lipids driven by kinase activity PIK3 recruited myosin motor proteins leads to contraction

what does transiently-lived membrane

refers to a type of cell membrane that forms temporarily during processes such as endocytosis, particularly during membrane fusion events associated with vesicle transport

what are phagolysosome

phagocytes and lysosomes

what do phagolysosomes use to break down particles

Degrative enzymes and free radicals degrade the particles

how does caveolin-dependent endocytosis work

Form from lipidraft hydrophobic loop they pinch off their cargo into compartments called cavesome these stay associate with the membrane

what does endocytosed mean

how is caveolin-1 made and how does it leave the golgi

it enters the ER travels to the golgi and leaves the golgi through

what do clathrin-coated pits form and how

a ligand binds to a receptor along the membrane these receptor recrite adaptor proteins, these adaptor proteins form a cap this process continues until dynamin acts like a band and buds this ring of calatherin. with the caps are removed leaving a naked ring that enters the cell

what steps are involved in clathrin-dependent endocytosis

what would you expect to happen if adaptor protein omited from clatherin-coated pits

if adaptor were proteins were ommited a coat it would not recruit proteins to form a ring

what would you expect to happen if protein omited

if proteins couldnt be recruited a ring could not form

what would happen if clathrin omitted

if clathrin was omitted it wouldn’t function

what would happen if dynamin was omitted

it could not bud off and would create a continuous pit

prokaryotic membrane fragments were used

it would not function as this pathway is not present in prokaryotic cells