Cell structure pt. 2 (exam 2) Flashcards
what’s the difference between translating mRNA on a ribosome on the rough ER vs a ribosome that’s loose in the cytoplasm
- if you’re being made on the membrane you’ll have something to do with the membrane
ex: - embedded in membrane
- secreted
- part of organelles that are surrounded by a membrane
ex: free enzyme or a protein used by the exoskeleton
function of ribosomes found on the surface of the rough ER
they carry out translation
function of kinesin in microtubules
- transport of vesicles
anterograde vs retrograde
anterograde
toward cell membrane (moving something out of the cell)
retrograde
toward cell body
_____ triggers retrograde
rabies
list the structure of a kinesin
tail = affinity for transport vesicles
stalk= 2 strands, twisted,tension buildup
head
briefly explain how kinesins work
- “walks along a microtubule track”
- walks the vesicle all the way to the end
vesicle transport is _____
highly enzyme dependent
microtubules: centrosomes and kinetochore
FUNCTION
- direction of chromosome movement
- highly ATP dependent
centrosome
- microtubule
- contains the centrioles from which the spindle fibers develop
kinetochore
- microtubule
- provides the major attachment point for the spindle microtubules during mitotic or meiotic division to pull the chromosomes apart
Colchicine at higher doses
- treat inflammatory response
- for cancer
- interferes w microtubule formation, therefore can’t form spindle fibers and stops mitosis
colchicine at lower doses
- can harm immune cells
- blocks the highway, affects transport
- used for immune diseases
which cells are the most susceptible for colchicine
the ones that are doing the most work
cilia, flagella, and dynein
- directs movement of cell or movement of material over cell surface
- microtubules
Dynein
- partly embedded in tubulin fiber
- microtubule based
- power a wide variety of motile processes within eukaryotic cells (includes cilia and flagella)
cilia
- 2 types: non motile and motile
- on the surface of many cells
- hair like, helps move things across the surface of a cell
flagella
- motility organelle that enables movement and chemotaxis
basement membrane and function
- this is in the ECM
- anchors down the epithelium to its loose connective tissue
location of basement membrane
between the epidermis and the dermis.
integral membrane proteins
proteins that span the entire length of the membrane
what connects the ICM to the ECM
laminin
fibronectin
what happens when you increase the laminin ratio
increases cellular quiescence (when cells don’t replicate)
passive or active transport?
endocytosis
active
passive or active transport?
exocytosis
active
passive or active transport?
cell membrane or the sodium-potassium pump
active
passive or active transport?
osmosis
passive
passive or active transport?
diffusion
passive
passive or active transport? facilitated diffusion
passive
diffusion
the movement of molecules with a gradient
- passive process
- doesn’t require energy
osmosis
- the diffusion of water across a membrane
- small quantities of water do diffuse
what does kidney filtration depend on?
certain cells being impenetrable to water
facilitated diffusion is also known as
carrier-mediated transport
facilitated diffusion
- passive transport
- uses integral membrane proteins as channels
- demonstrates specificity (Ex: Na+, K+, water, etc)
- can be open to allow free diffusion or closed (Gated) to restrict diffusion
aquaporins
- non gated
channels that allow for osmosis - open channels
distribution of aquaporins in kidney membranes are regulated by..
hormones
active transport
- moves against gradient
- uses pumps to concentrate molecules
- requires energy
- utilizes integral membrane proteins
receptor mediated endocytosis
- stimulated by specific ligand binding receptor molecules
- receptors have G protein signaling (use 2nd messengers)
- triggers vesicle formation by clathrin
- requires energy
explain clathrin binding
- clathrin binding is stabilized by adaptors.
dynamin
- clips off the vesicle in receptor mediated endocytosis
pinocytosis
- endocytosis
- intake of extracellular fluid
- requires energy
vesicle formed through the action of actin fibers
explain endocytosis via receptor mediated/viral attack
- viral particles bind to receptors
- tricks cell into internalizing virus
- virus entry is specific to cell receptors (there’s specificity to attack)
requires energy
exocytosis
- transport vesicles released from golgi
- anchored to membrane by SNARE complex
- fusion causes secretion of contents
- can be constant or unregulated
regulated exocytosis
requires a signal Ca2+
- has to trigger SNARE
