Cells and Organelles Flashcards
what is the function of a flagellum
help with movement
what is a flagellum made of
microtubules
list the cilia types
respiratory epithelial cells
brain ependymal cells
epithelial cells lining the fallopian tubes
what are erythrocytes and what is their structure
red blood cells
anucleate and biconcave
what is the role of keratinocytes and how is its structure supporting this
makes a lot of protein = extensive RER
what are microtubules and what is their role
dynamic structures (cell movement/ intracellular transport of organelles/ mitotic spindle (mitosis))
what are microtubules made of
polymers of a and b tubulin
what stabilises microtubules
proteins
tau protein
condition when cilia are defective
kartagener’s syndrome
condition when microtubules are defective
Alzheimer’s disease
what is the cause of Tay Sachs disease and list its symptoms/ outcomes
build up of gangliosides in the brain and spinal cord; caused by gene mutations; seizures/sight/hearing/unlikely to live past 5
how are mitochondrial disorders inherited and what does it cause
dysfunction of the mitochondrial respiratory chain; clinically heterogenous group (down female line)
mitochondrial inheritance comes from the ovum
3 donor babies
where are tight junctions and what is their function
apical
gate = regulation of paracellular permeability (ions/solutes/water)
fence = formation of apical and basolateral intramembrane diffusion barrier (makes polar)
tight junctions (gate defective)
hypomagnesaemia (intestinal/ renal permeability; enteric pathogens; obesity; coeliac disease
tight junctions (fence defective)
loss of polarity; less differentiated; cells can detach; progression towards cancer
what are cellular junctions
transmembrane protein complexes
list the cell-cell junctions
adherens (actin)
desmosomes (ifs)
list the cell-ECM junctions
focal adhesions (actin)
hemidesmosomes (ifs)
give an example of a channel forming junction
GAP junctions - cell-cell contact; composes of hexamers of Connexins; allow passage of small molecules
what does defective hemidesmosomes lead to
epidermolysis bullosa (butterfly skin)
caused by genetic defects
what are cytoskeletons
intermediate filaments - structural role/ mechanical strength
how does a cytoskeleton function as a motor protein
kinesins move cargo away from the centrosome (adjacent of nucleus, centre where microtubules are anchored and initial polymerisation)
dyenins move cargo towards
what are axonemes
the cytoskeletal component of cilia and flagella
allow for bending
what are axonemes comprised of
microtubules and dyenin actin filaments (microfilaments)
polymerised actin
myosin (allows movement)
