M+C lecture 1 Flashcards
what are 3 functions of cell membranes within eukaryotic cells?
1) different environments
2) metabolic regulation - keeping enzymes and substrates in different locations
3) sequestration of toxic substances
why do internal compartments of mitochondria and chloroplasts have an acidic PH?
to drive ATP synthesis by causing a proton gradient
what are 3 processes which take place in the genome?
1) DNA replication
2) transcription
3) RNA processing
where does translation take place?
in the cytoplasm
where does RNA splicing take place?
in the nucleus
why is the cytoskeleton important for animal cells and what does it do?
because they don’t have cell walls so they provide rigidity shape and structure (cytoskeleton)
how do vesicles travel from the ER to the golgi?
along skeletal trackways
what comprises 10% of total cell protein?
actin
what do microfilaments do?
contraction - actin fibres glide and contract with myosin
what do microtubules do?
provide a trackway for movement of organelles and vesicles and determine cell shape
what do intermediate filaments do?
anchor and position nucleus and give the cell flexibility
what do motor proteins do?
powered by ATP move molecules and organelles around the cell by attaching to receptors and walking them along microtubules
which way does Kinesin travel?
AWAY from nucleus towards plus end
which way does dyenin travel?
TOWARDS nucleus and minus end
what are microtubules made out of?
alpha and beta tubulin
what are microfilaments made out of?
twisted actin subunits
what are intermediate filaments made out of?
supercoiled fibrous proteins changes depending on cell type
what is the nuclear lamina?
lining of inner surface of nuclear envelope
what is responsible for the bending movement in cilia/flagella?
dyenin motor proteins in between each microtubule doublet
what is the microtubule pattern in plant cell walls?
microfibrils made of the polysaccharide cellulose embedded in a matrix of polysaccharides and protein
what is the job of cortical microtubules?
form a template for deposition of cellulose in bands
