Term
| Describe 3 roles of the plasma membrane |
|
Definition
recieve info
import & export molecules
move & expand cell |
|
|
Term
|
Definition
intracellular liquid
liquid and organelles (not nucleus) |
|
|
Term
| the lipid bilayer is impermeable to what? |
|
Definition
|
|
Term
| phospholipids are ampipathic. What does this mean? |
|
Definition
| hydrophobic & hydrophilic |
|
|
Term
| what is the most common phospholipid in cell membranes? |
|
Definition
|
|
Term
| What type of membrane movement with phospholipids is energetically unfavorable? |
|
Definition
| flip flopping -rarely happens |
|
|
Term
| What leads to greater fluidity at lower temperatures |
|
Definition
| Shorter hydrocarbon chains & cis-double bonds |
|
|
Term
| What does cholesterol do to lipid bilayers? |
|
Definition
makes membranes more rigid & less permeable
to small molecules |
|
|
Term
Where is Phosphatidylinositol found in the plasma membrane?
Where are glycolipids found? |
|
Definition
Phosphatidylinositol only in inner leaflet;
glycolipids only in outer leaflet. |
|
|
Term
What are integral membrane protiens?
What are peripheral membrane proteins? |
|
Definition
need to disrupt bilayer to release (detergents)
only need to disrupt protein-protein
interactions to release |
|
|
Term
| if a protien is spanning the lipid bilayer, what is is likely to be? |
|
Definition
|
|
Term
How many membrane-spanning domains are
needed to form a pore? |
|
Definition
|
|
Term
When there are Stretches of 20-30 amino acids with a high degree of hydrophobicity
what are they likely to be? |
|
Definition
| membrane spanning regions. |
|
|
Term
| are membrane protiens mobile? |
|
Definition
|
|
Term
| can lateral membrane mobility of membranes be restricted? |
|
Definition
|
|
Term
| Eukaryotic cells are lined with a layer of what? |
|
Definition
|
|
Term
| what to membrane transport proteins do? |
|
Definition
| transport small, water soluble molecules across the membrane |
|
|
Term
| How do small molecules and ions enter the cell? |
|
Definition
|
|
Term
another name for passive transport
what does it mean> |
|
Definition
facilitative diffusion
passing a molecule down it's concentration gradient |
|
|
Term
|
Definition
| Bind solutes, undergo conformational change & release solute on other side |
|
|
Term
| What do transporters carry? |
|
Definition
sugars, amino acids &
nucleosides across membrane. |
|
|
Term
| What are some ways active transport is powered? |
|
Definition
coupled driven- move them with ions going with their gradient
ATP driven
light driven (Bacteria & archae |
|
|
Term
| What does the Na/K pump do? |
|
Definition
moves them against elecrochemical gradients using ATP
3 Na OUT 2 K in |
|
|
Term
| what is the purpose of active transport? |
|
Definition
| maintain ion balance in a cell |
|
|
Term
What is a uniport?
symport?
Antiport? |
|
Definition
a) moves one ion at a time
b) moves 2 ions together
c)moves 2 ions opposite directions |
|
|
Term
| what does the Na/glucose symport do? |
|
Definition
uses Na+ gradient to
transport glucose into cell |
|
|
Term
What is the specivity of transporters?
WHat is the specivity of channels? |
|
Definition
ligand binding
size & charge |
|
|
Term
| What do channel proteins do? |
|
Definition
form pores to allow solutes to go through
allows many molecules to go through |
|
|
Term
| What kind of gated channels are there? |
|
Definition
ligand gated
voltage gated
stress gated |
|
|
Term
| How does that Na channel exclude K? |
|
Definition
| too narrow, so 10X more permeable to Na |
|
|
Term
| How is the K+ channel selective against Na? |
|
Definition
| Na is too small to interact with carbonly O2 |
|
|
Term
What are the forces that drive an ion across a membrane?
What equation represents the ballance between the two of these? |
|
Definition
elecctrical membrane potentiial
Concentration gradient of the ion
Nernst equation |
|
|
Term
| What is the Nernst equation? |
|
Definition
V=62log10 (c0-Ci)
V= membrane potential
C0 & Ci =out & in ion concentrations
all at 37 degrees |
|
|
Term
| What do mitochondria, chloroplasts & prokaryotes use to harness energy? |
|
Definition
|
|
Term
| What is cChemiosmostic coupling? |
|
Definition
electron transport drives pump to move protons across membrane
then proton gradient is harness by ATP synthase to make ATP
(electrochemical energy converted to chemical energy) |
|
|
Term
| Chemiosmotic coupling gives energy for what processes? |
|
Definition
active membrane transport
ATP synthesis
Flagella rotation |
|
|
Term
| mitochondria & chloroplasts both use what to harvest energy? |
|
Definition
| electron stransport processes |
|
|
Term
| what are the folds in mitochondria called? |
|
Definition
| christae- forms inter membrane |
|
|
Term
| what structure is mitochondria like? |
|
Definition
|
|
Term
How are more mitochondria and chloroplasts made?
do they have their own genome? |
|
Definition
|
|
Term
| what does oxidative phosphorylation do? |
|
Definition
turns NADH to NAD+ and H20
turns ADP + P to ATP |
|
|
Term
| what dontes electrons to the electron transport chain? |
|
Definition
|
|
Term
| why is the E transport chain slow and step by step |
|
Definition
| to harnes as much energy as possible |
|
|
Term
| what three enzyme complexes pump protons across membranes from the metrix to intermembrane space? |
|
Definition
NADH dehydrogenase complex
cytchrome b-c1 complex
cytochrom oxidase complex |
|
|
Term
| what happens when protons are pumped across the inner membrane? |
|
Definition
| creates an elecrochemical proton gradient |
|
|
Term
| does redox potential increase or decrease along ETC? |
|
Definition
|
|
Term
| Where is the ETC in a chloroplast? |
|
Definition
|
|
Term
| What to antenna pigments do? |
|
Definition
| absorb light & transfer energy to a special pair of chlorophpyl molecules in reaction center |
|
|
Term
| light energy is harvested by what? |
|
Definition
| reaction center in chlorophyll molecules |
|
|
Term
| where do high energy electrons travel down the ETC? |
|
Definition
|
|
Term
| the light reaction generates what molecules? |
|
Definition
|
|
Term
| what generates high energy electrons for reducing NADP+ to NADPH? |
|
Definition
|
|
Term
| what can produce ATP w/o NADPH or O2? |
|
Definition
| cyclic photophosphorylation |
|
|
Term
| Chloroplast ATP synthase is driven by what? |
|
Definition
| PH NOT membrane potential |
|
|
Term
| Thylakoid membrane is permeable to what ions? |
|
Definition
|
|
Term
| what organelles make ATP in plants? |
|
Definition
| BOTH Chloroplasts and mitochondria |
|
|
Term
| what is most of the cell composed of? |
|
Definition
|
|
Term
what is the nuclear compartment topologically equivalent to?
what babout the ER? |
|
Definition
cytosol
extracellular space |
|
|
Term
| what organelles are involved in secretory & endocytic pathways? |
|
Definition
| ER, golgi apparatus endosomes, lysosomes, transport vesicles |
|
|
Term
| what are 4 distinct compartment types? |
|
Definition
Nucleus & cytosol
mitochondria
Plastids
organelles in secretory & endocytic pathways |
|
|
Term
| what organelles are plastids? |
|
Definition
| chloroplasts, storage plastids, chromoplasts |
|
|
Term
| where is the info for making new organelles stored? |
|
Definition
| not in DNA, but in organelle itself |
|
|
Term
| what half of the the ER membrane are phospholipids added to? |
|
Definition
|
|
Term
| How does the ER membrane move to other membranes? |
|
Definition
|
|
Term
| what are the 3 ways membrane enclosed organelles import proteins> |
|
Definition
nuclear pores
across membranes
vesicles |
|
|
Term
| what do sorting signals do? |
|
Definition
| target prteins to diff compartments of the cell |
|
|
Term
| what is a signal sequence? |
|
Definition
target protiens to correct destination
located on end |
|
|
Term
| What goes on in the nulceus? |
|
Definition
| DNA storage, DNA replication, RNA replication, RNA processing |
|
|
Term
| where does translation occur? |
|
Definition
|
|
Term
| what does the nuclear envelope do? |
|
Definition
| encloses DNA & defines nuclear compartment |
|
|
Term
| what does the nuclear envelope do? |
|
Definition
| encloses DNA & defines nuclear compartment |
|
|
Term
| what do nuclear pore complexes do? |
|
Definition
| regulate transport into & out of nucleus |
|
|
Term
| how is the outer nuclear membrane similar to ER |
|
Definition
|
|
Term
| what does the inner nuclear membrane do? |
|
Definition
| has anchoring sites for nuclear lamina (protein meshwork for support) |
|
|
Term
| what is the nuclear lamina composed of> |
|
Definition
| intermediat filaments or lamins that form a lattics for shape |
|
|
Term
| what oes the nuclear lamina bind to? |
|
Definition
| inner membrane & chromatin |
|
|
Term
| where are telomeres and centromeres typically found? |
|
Definition
| attached ot nuclear envelope |
|
|
Term
| what specifically is too large to pass through NPCs by diffusion? |
|
Definition
|
|
Term
| what is a NPC composed of? |
|
Definition
| 30 NPC proteins called nucleoporins |
|
|
Term
| what in the nucleus blocks diffusions of large molecules? |
|
Definition
| tangled mesh of central pores |
|
|
Term
| what promotes the transport of folded proteins into the nucleus? |
|
Definition
| Nuclear localization signal |
|
|
Term
|
Definition
| 1 or 2 short stretches of basic amino acids |
|
|
Term
| what family are nuclear import receptors or importins from? |
|
Definition
| kyryopherin protein family |
|
|
Term
| what drives nuclear imports? |
|
Definition
|
|
Term
What imposes directionality on
transport via NPCs? |
|
Definition
|
|
Term
| How is Ran-GDP imported into nucleus? |
|
Definition
| uses its own transporter. |
|
|
Term
| what is Export from nucleus mediated by? |
|
Definition
nuclear
export receptors or exportins |
|
|
Term
| Dephosphorylation of what permits nuclear entry? |
|
Definition
|
|
Term
| Cell signaling induces IκB degradation allowing what to enter? |
|
Definition
|
|
Term
| Mature mRNAs are exported from nucleus as |
|
Definition
|
|
Term
Membrane-enclosed organelles import proteins
by of one of three mechanisms |
|
Definition
transport through nuclear pores
across membranes
vessicles |
|
|
Term
| what mechanism drives nuclear import? |
|
Definition
|
|
Term
|
Definition
| imposes diecetionality on transport by using NPCs |
|
|
Term
| what are all protiens initially translated by? |
|
Definition
|
|
Term
| what directs protiens to correct destination? |
|
Definition
| signal sequences on N terminus protein |
|
|
Term
| what forms the amphipathic a helix? |
|
Definition
| matrix miochondrial signal sequence |
|
|
Term
| what are soem mitochondrial prtoein translocators? |
|
Definition
|
|
Term
| what are soem mitochondrial prtoein translocators? |
|
Definition
|
|
Term
| what state are proteins in when translocated across mitochondrial membrane? |
|
Definition
|
|
Term
what chaperone prevents folding in the cytosol?
what binds prteins & pulls them through the membrane? |
|
Definition
Cytosolic Hps70
Mitochondrial Hsp70 |
|
|
Term
| what process of protein import is similar to that in chloroplasts? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| what is produced in the ER? |
|
Definition
| lipids, transmembrane prteins & secretory proteins |
|
|
Term
|
Definition
|
|
Term
| where is the entry point for a secretory pathway? |
|
Definition
|
|
Term
| what is the pulse-chase experiment? |
|
Definition
| found the secretory pathway of amino acids by labeling some radioactivly |
|
|
Term
| where does translation of ER bound prteins begin? |
|
Definition
|
|
Term
| waht escorts ribosomes to SRP receptors on the ER membrane? |
|
Definition
|
|
Term
|
Definition
| acts like ratchet to pull prteins throough ER (need atp) |
|
|
Term
start and stop transfer sequences
hydrophilic or hydrophobic? |
|
Definition
|
|
Term
| if more positively charged amino acids PRECEDE the start transfer sequence, what what enters the ER lumen first? |
|
Definition
C terminus
if follow STS, then N terminus |
|
|
Term
| what is an example of a serpentine transmembrane protein? |
|
Definition
|
|
Term
|
Definition
| form vesicles from membrane |
|
|
Term
| what are two fucnctions for a coat? |
|
Definition
concentrates specific membrane proteins in a patch
shapes forming vesicle |
|
|
Term
what does
COPII do?
COPI?
Clatherin? |
|
Definition
transitional ER to Golgi
golgi to ciesternae or ER
endocytosis or golgi to endosomes |
|
|
Term
| what links membrane proteins & clatherine? |
|
Definition
|
|
Term
| what does dynamin GTPase do? |
|
Definition
| pinches off coated vesicles |
|
|
Term
|
Definition
| actsto sort transport vesicels to the correct membranes |
|
|
Term
|
Definition
| catalyze membrane fusion reactions and medidate membrane fusion |
|
|
Term
| where does proteolytic processing of unsulin occur? |
|
Definition
|
|
Term
| what mediates prtoein folding & multiprotein complex assembly? |
|
Definition
Bip
(keeps unfolded proteins in ER |
|
|
Term
| what facilitates the correct disulfide bonds? |
|
Definition
|
|
Term
| What anchors proteins to the plasma membrane? |
|
Definition
|
|
Term
| what occurs as proteins enter the ER? |
|
Definition
|
|
Term
| what is used as a tag to monitor protein foldin the ER? |
|
Definition
|
|
Term
| what happens to proteins that fail to fold? |
|
Definition
| exported & degraded by proteasome |
|
|
Term
| what does Activated IRE1 do? |
|
Definition
| initiates splicing reactions to produce functional transcription factor |
|
|
Term
|
Definition
lumenal protein
membrane protein
both are resident ER proteins with retrieval siglans to return |
|
|
Term
|
Definition
| sorting & dispatch for proteins received from the ER |
|
|
Term
glycosltransferases do what?
glycosidases do what? |
|
Definition
add sugars to golgi
remove sugars from golgi |
|
|
Term
| what are 3 ways out of trans golgi network? |
|
Definition
secretory vesicles
constitutive secretory pathways
regulated pathways |
|
|
Term
| proteins can be targeted to apical or basolateral domains by what two mechanisms? |
|
Definition
direct sorting of protiens
indirect sorting by endosomes |
|
|
Term
|
Definition
|
|
Term
| what two things come together to form a lysosome? |
|
Definition
| fusion of endosomes & transport vesicles |
|
|
Term
| what directs proteins to a lysosome? |
|
Definition
| phosphorlylation of mannose |
|
|
Term
|
Definition
|
|
Term
| receptor mediated endocytosis is a form of what? |
|
Definition
|
|
Term
| what receptor imports cholesterol into the cell? |
|
Definition
|
|
Term
| what is an early endosome>> |
|
Definition
| sorting station for endocytic vesicles |
|
|
Term
| what is synaptic signaling? |
|
Definition
| a specialized type of paracrine signaling |
|
|
Term
| differences between endocrine & synaptic signalling |
|
Definition
slow & fast
specifivity determined by receptors or synapses |
|
|
Term
| what do GAP junctions do? |
|
Definition
| give fast & symetric communication between cells |
|
|
Term
| what does nitroglycerine do? |
|
Definition
| converted to NO & used to treat heart pain |
|
|
Term
|
Definition
| by directly activating intracellular receptors |
|
|
Term
| what does thyroid hormone binding do? |
|
Definition
| converts receptor from a repressor to an activator |
|
|
Term
| can the same molecule be uses for endocrine or paracrine signaling? |
|
Definition
|
|
Term
| how would you describe steroid & thyroid hormones? |
|
Definition
| small, hydrophobic signaling molecules |
|
|
Term
| do nuclear receptors activate or repress gene transcription? |
|
Definition
|
|
Term
| what are two types of molecular switches in signaling pathways? |
|
Definition
signal w/ phosphorylaiton
or by GTP binding |
|
|
Term
| what do scaffolding proteins do? |
|
Definition
| increase local concentration of signaling factors & reduce cross talk between pathways |
|
|
Term
| in response to ligand binding. what serves as a docking site for signal proteins? |
|
Definition
| phosphorylation of cytosolic tail of receptors |
|
|
Term
| what do modular domains do? |
|
Definition
| mediate binding between signal transduction pathways |
|
|
Term
| what do coincidence detectors do? |
|
Definition
| integrate signals from multiple pathways |
|
|
Term
| what are 3 types of surface receptors? |
|
Definition
ligand binding
g protein coupled receptors
enzyme-coupled receptors |
|
|
Term
| sompe peptide signaling molecules? |
|
Definition
|
|
Term
|
Definition
| lipid signaling molecules that bind to cell surface receptors |
|
|
Term
valium does what?-
Nicotine
Morphine & Heroine? |
|
Definition
relieves anxiety
constrict blood vessels/Inc. BP
euphoria (stimulates g protein opiate receptors) |
|
|
Term
| what to G protein copuled receptors do? |
|
Definition
| activate trimeric GTP binding proteins (Gproteins) |
|
|
Term
| half of all drugs work through what receptors? |
|
Definition
|
|
Term
| how do GPCR's activate G proteins? |
|
Definition
| by causing exchange of GTP for GDP |
|
|
Term
| hydrolysis og GTP does wha to a Ga subunit? |
|
Definition
|
|
Term
| what does a Gby complex do? |
|
Definition
| activates K channels to dlow down heart in response to acetylcholine |
|
|
Term
| what does a Gby complex do? |
|
Definition
| activates K channels to dlow down heart in response to acetylcholine |
|
|
Term
| what does a Gby complex do? |
|
Definition
| activates K channels to dlow down heart in response to acetylcholine |
|
|
Term
|
Definition
| a second messenger in hormone signaling |
|
|
Term
| do G proteins stimulate or inhibit adenylyl cyclase? |
|
Definition
|
|
Term
| what does protein Kinase A do? |
|
Definition
| mediates most effects of cAMP |
|
|
Term
| what does adrenaline do to skeletal muscle? |
|
Definition
| stimulates glycogen breakdown in it |
|
|
Term
| what does prtoein phosphatase 1 do? |
|
Definition
| counteracts protein kinase A |
|
|
Term
| sperm entry trigers what wave? |
|
Definition
| Ca wave that initiates development |
|
|
Term
|
Definition
high affinity Ca receptor
(activates CaM kinases) |
|
|
Term
| Ras, Faf MEK & ERK are all what? |
|
Definition
| growth factors that help with proliferation & differentation of cells |
|
|
Term
| where do protein X & Y act in comparison to Ras? |
|
Definition
X acts upstream of Ras
Y acts downstream |
|
|
