lecture 5 Flashcards
nucleus
stores genetic information
dna is packaged inside
how is dna packaged
first in nucleosomes
then into 30nm fibres
how are nucleosomes and 30nm fibres are set up with
histome protiens
nucleois
downtown
sight of rRNA transcription
endomembrane system
set of organelles connected via vesicles
start er to golgi to either plasma membrane or lysosome
organelle recycling
golgi to er
endoplasmic recticulum has two classes, what are they?
bound and free ribosomes
bound ribosomes
associate in cytoplasm side of er membrane
translate protien within endomembrane and secretion
free ribsomes
found in cytoplasm
translate all other protiens (mitochondrial, cytoplasm, nucleus)
not shipped through endomembrane system
in the golgi, what are the two ways that cargo travels in the cysternae
vesicle trafficking and cisternal maturation
evidence for vessicle trafficing
small vessicles are observed associating with golgi
cisternal specific enzymes
evidence for cisternal maturation
molecukes too big to fit in golgi associate with vessicles and go to golgi
what is the working model for the golgi
cisternal maturation moves cargo antergograde (cis to trans)
vessicle trafficking moves cargo reterograde (trans to cis)
lysosome
digestive
low pH prevents autophagy
cell stomach
autophagy
if an ezyme finds itself in cytoplasm and leaks, does not work there
can be intentional
tay sachs
lack an ezyme to digest a particular lipid
three sections of cytoskeleton
mictrotubles, microfillaments, intermediate fillaments
microtubules
polymers of tubulin (alpha and beta dimer)
assenble in protofilament (euk. flag)
what are the 2 motor protiens of microtubules
dyenin: - end directed, wlaks to nucleus interior
kinesin: + end directed, walk toward periphery (end) of cell
microfilaments
polymers of actin
rope-like stretch resistant
myosin acts as motor
intermediate fillament
heterogenous polymer
desmin - in desmosome
lamin - in nuclear in lamina
kertin - hair and nails
no motor protien
rope-like stretch resistant
