BMS 124 Osmosis terms Q2

what can pass the semipermeable membrane?

1. O2 and CO2? small and nonpolar?

2. H20 small and polar?

3. large and nonpolar?

4. large and polar?

5. highly polar charged?
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what can pass the semipermeable membrane?

1. O2 and CO2? small and nonpolar?

2. H20 small and polar?

3. large and nonpolar?

4. large and polar?

5. highly polar charged?
1. yes
2. yes, slow
3. yes, slow
4. no
5. no
w/o cholesterol, the phospholipid is _________ at low temps and is _________ at high temps
brittle and less fluid at low temps

leaky and weak at high temps
function of cholesterol?
at high temp?
at low temp?
makes the cell membrane more fluid and durable regardless of temp


at low temp, it keeps the phospholipids from packing too tightly together, increasing fluidity

at high temp, it pulls tgt the phospholipids,
two types of transport proteins
channels, carrier proteins enzymes (ATPases)
transport proteins
move molecules that cant freely diffuse across the membrane
_________ receptors that take input from outside and bring it inside of cell
e.g hormones, cytokines, or growth factors
cell surface receptors
_________ and _________ are unique to each cell

they help cells recognize each other
glycoproteins and glycolipids
are proteins and cholesterol static in the cell membrane?
no, they move around!
_________ anchor to neighboring cells
adherens junctions
what are the 3 types of passive transport
diffusion, facilitated diffusion, osmosis
_________ is driven by the difference in concentration gradient - will stop once equilibrium is reached - for small and nonpolar moleculesdiffusion_________ is for large and polar molecules -involves channels and carrier proteinsfacilitated diffusion_________ is the movement of water across the membrane, driven by _________osmosis, osmotic pressure_________ requires molecules to be transferred against their concentration gradientactive transport_________ active transport directly uses ATP as fuel e.g _________primary active transport, Na+/K+ ATPase (double action pump)_________ active transport does not directly require ATP, instead it uses an electrochemical gradient e.g _________secondary e.g sodium- glucose transporter_________ is when cells take in large substances such as proteins, fat droplets, and other cellsbulk transportbulk transport uses _________ and _________endocytosis and exocytosiscell to cell junctions are ONLY found between _________ cells and are most abundant in _________tissueimmobile, epithelialwhat are the 3 types of cell to cell junctionstight junctions, adherens junctions and gap junctions_________ junction anchor cells together and prevent separationadherensthree component of the adherens junctionscadherins, protein plaques, and actin filaments_________ create continuous networks of interconnected cells via actinadherens junctionswhich junction is important for tissue exposed to constant shearing and abrasive forces?adheren junctions_________ junctions seal 2 plasma membrane of adjacent cells tgttight_________ junctions are important in gastrointestinal tract to prevent bacteria from entering and water from seeping outtightthe blood brain barrier utilized _________ junctions to prevent harmful material in the blood from reaching the CNStight_________ and _________ in leaky junctions have _________ pores that allow ions to pass through e.g in the proximal tubule of the kidneyclaudins and occludins, ion_________ junctions allow cells to communicate w/ each othergap_________ engulf extracellular materialendocytosis_________expel material into extracellular spaceexocytosisdo enocytosis and exocytosis require ATP?yeswhat are the 3 types of endocytosisphagocytosis, pinocytosis, receptor-mediated endocytosisduring phagocytosis, _________ is formed to engulf the bacteriaphagosomeduring phagocytosis, the phagosome and lysosome combine to form _________, which contain enzymes to destroy bacteriaphagolysosome_________ means the "cell drinks"pinocytosis_________ is when the cell plasma membrane invaginate and forms vesicle --> then release into extracellular spacepinocytosisduring receptor-mediated endocytosis, the endosome separates the _________ from _________, by using _________ to lower the pHLDL from receptors, ATPhow do vesicles move during exocytosis?rely on the cytoskeleton_________, _________, _________ provide structural stability for the cytoskeletonmicrofilaments, microtubules, and intermediate filaments_________ junctions are made of a tubular protein called connexonsgapwhat is the purpose of connexons? (a type of gap junction, which is involved in cell communicaion)they permit electrical communication w/ ions to coordinate muscle contraction in smooth muscle cells and cardiac myocytestight junctions are made of _________ and _________ . they function to prevent movement of solutes between cells.claudins and occludinsAn investigator is studying the myometrial cells of the uterus during pregnancy. Just prior to and during labor, it is noticed that the myometrial cells upregulate cell junctions to facilitate synchronization of uterine contraction. These cell junctions are made of which of the following protein(s)?connexonshemidesmosomes are made of ____________, which connect keratin (intermediate filament) in the basal cells to the underlying basement membraneintegrinsdesmosomes are made of ____________ and ____________.intermediate filaments and cadherinsAn investigator is studying bacterial virulence factors that help specific bacteria evade the host immune response . Group A streptococci are found to express M protein, which helps the bacteria to avoid being endocytosed by immune cells. Which of the following structures are unique to this endocytosis pathway?phagosomeswhat are the 3 components of the ECMadhesive proteins, structural proteins, and proteoglycans_______ is the most common structural protein, resist tension, and stretchable. it is also released as procollagencollagenProcollagen turns into________ after collagen peptideases snip off the endstropocollagen4 most common types of collagen I- Be So Totally II- Cool III- Read Books IV- BroI- bone, skin, tendons , II- cartilage III- reticular fibers IV- basement membrane_____ has a protein core and chains of sugar (GAGs)proteoglycansGAGs are _____ fill space between cells and attract____glycosaminoglycans, waterwhat are the 3 structural/fibrous proteins in ECM?collagen, elastin, and keratinadhesive proteins includeintegrin and cadherinsemipermeable depends on _________,_________,_________size, polarity and charge_________ regulates what comes in and out of cellcell membrane________________ signals are from cell to its OWN receptorsautocrine________________ signals are to target cells nearbyparacrine________________ signals go to target cells that are FURTHER awayendocrinehormones secreted into the bloodstream and cytokines released at site of injury are examples of ________________ signalsendocrine________________ are signaling molecules that are either hydrophobic or hydrophilicligandscan hydrophobic signaling molecules (ligands) freely float in the extracellular space?nohow are hydrophilic signaling molecules transported into target cells?bind to receptors (transmembrane protein) on the cell surface bc they cannot diffuse pass the cell membrane --> the transmembrane prot trigger a intracellular signaling pathway inside the cellhow are hydrophobic signaling signaling molecules (ligands) transported into target cells?they are transported into the target cells by carrier proteins --> and then diffuse pass cell membrane and bind to receptor proteinwhat are the three stages of cell signaling pathways?reception, transduction, and cell's response to the signalwhat happens during reception? (rmr this is the first stage of cell signaling pathway)when the target cell's receptor binds to a ligand (think of key fitting into a lock)what happens during transduction?the receptor protein changes in some way and that activates intracellular molecules (the 2nd messengers)what are the 3 classes of transmembrane proteins?G protein coupled receptors, enzyme-coupled receptors, and ion channel receptors___________________ are 7 pass transmembrane receptors they are really long proteins that have one extracellular end (which binds to the ligand), snake like protein dips (going in and out of the cell membrane 7x) and eventually ends on the inside of the cellg protein coupled receptorsthe end of the G-protein coupled receptors (that is w/in the cell) activates intracellular prots called______________guanine nucleotide- binding prots or G protsG proteins are made up of 3 subunits called?alpha, beta, and gammathe _________ and _________ subunits of the G-protein are anchored to the _________ and keep the G protein right next to the receptorsalpha and gamma cell membraneG prot (_________ subunit) binds to _________ when they are inactive --> makes the 3 subunits stay tgtalpha, guanosine diphosphate aka GDPwhat happens when a ligand binds to the G- protein coupled receptor?1. G-protein coupled receptors changes its shape 2. this allows the G prot (alpha subunit) to release GDP and bind to GTP instead 3. when alpha is bind to GTP, alpha separates from the other two subunits (beta and gamma) 4. alpha is free --> can interact w/ other prots (can stimulate/inhibit them)what happens to the alpha subunit if it acts on other prot?it turns GTP into GDP --> then alpha will join beta and gamma --> forming the 3 subunit again (meaning G prot will be turned off)how many types of G prots are there?Gq, Gi, and GsGq protein activates _________ Gs stimulates _________ Gi inhibits _________phospholipase C, which is found on the cell membrane adenylate cyclase adenylate cyclasewhat happens when Gq protein activates _________ ? what happens to Ca2+ concentration in the cytoplasm? how does this affect kinase C ?phospholipase C --> cleaves a phospholipid into inositol trisphophate and diacylglyercol --> inositol trisphosphate go to ER (endoplasmic reticulum where Ca2+ channels open) --> Ca2+ flow into cytoplasm --> changes electrical charge of cell (depolarization) meanwhilee --> diacylglyercol remains attached to cell membrane and binds to kinase C --> w/ increase of Ca2+ lvls bc inositol, Kinase C can now activate other prots bc phosphorylating themwhat happens after adenylate cyclase is stimulated by prot Gs?--> adenylate cyclase converts ATP to cAMP -->cAMP binds to kinase A (has 2 parts: regulatory and catalytic subunits) --> separates those subunits on Kinase A --> catalytic subunit of Kinase A can now phosphorlyate target prots and trigger a cell responseGi prots act on the same enzyme (adenylate cyclase) as Gs prot, why is this impt?impt in inactivating cells causes a negative feedback on prot Gs_______________ are usually single pass transmembrane prot, meaning they have only one transmembrane segment, and their intracellular end has intrinsic enzyme activityenzyme- coupled receptorsenzyme- coupled receptors have two parts- one domain is the ________ and the other domain is ________receptor, enzyme (usually a pro kinase that phosphorylates the receptor domain)3 main types of enzyme coupled receptorreceptor tyrosine kinase, tyrosine kinase associated receptors, and serine/threonine kinasemost common enzyme coupled receptorsreceptor tyrosine kinaseshow do receptor tyrosine kinases work? what happens when a ligand binds? is dimerization involved? why?they cant phsophorylate their own tyrosine side chains --> so when a ligand binds, two receptor chains come tgt --> dimerize and cross-phosphorylate --> triggers confromational change--> high affinity binding sites for 2ndary messengers (which become activated) --> triggering signaling pathwayreceptor tyrosine kinases vs tyrosine kinase associated receptorstyrosine kinase associate receptors- have no intrinsic activity, instead they are associated w/ cytoplasmic tyrosine kinases (which phosphorylates target prots)receptor serine/threonine kinases have two classes: ______ and ______ how are they involved in signaling pathways when a ligand binds?type 1 and type 2 ligand bind--> two types come tgt --> type 2 receptor phosphorylate and activate type 1 receptors (which phosphorylates target prots)ion channel receptors are usually ______ unless bind to a ligandclosedion channels allow ________, _________, _______ to PASSIVELY flow down their gradient --> which leads to a shift in electrical charge--> triggering a cell response!chloride, calcium, sodium3 types of transmembrane proteins G-coupled protein receptors --- Enzyme-coupled receptors --- ion channel receptorsG-coupled protein receptors - Gp- activates... Ca2+ lvls go up --> kinase C - Gs - activates... adenylate cyclase.. ATP--> cAMP.. catalytic subunit of kinase A - Gi - inhibits adenylate cyclase, neg feeback of Gs enzyme coupled receptors - single pass transmembrane proteins -intrinsic enzyme activity - based on AA at which receptor is phosphorylated ion channel- allow chloride, calcium, sodium to passively flow down their gradient