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105 Cards in this Set
- Front
- Back
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Once again, the 4 basic tissue types
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Epi, CT, muscle and nervous
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What's the metabolic understanding of cell theory?
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Ignoring H20, nearly every molecule in a cell is based on carbon: nucleic acis, carbs, lipids, proteins.
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The highest resolution capacity of TEM?
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details that are .2 nm apart
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Important life processes of the human body
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Metabolism, differentiation, growth, responsiveness, movement. DUH
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Hypertrophy versus hyperplasia
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Hypertrophy is the increase in size of something, hyperplasia is the excessive proliferation of cells.
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Ribosomal units of eukaryotic cells
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80S (60+40) (know that this is bigger than bacteria)
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Passive versus active cellular processes
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Passive: Simple diffusion, osmosis, filtration, facilitated diffusion (channels that do not require energy)
Active: 1 and 2 active transport, exocytosis, endocytosis |
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4 components of cytoplasm
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Cytosol, Organelles, Cytoskeleton, Inclusions
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What does gel-sol really mean?
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Think about it. Cells appear roundish, why? The outer rim, or cortex, of a cell is gelatinous. All the stuff in the middle is gooey and mutable, or sol state. So all those vesicles and packaged proteins can move to the membrane.
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What 3 things are in chromatin?
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DNA, histones, non-histone bound proteins.
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What is the central dogma?
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That the nuclear envelope is what separates us from bacteria: transcription and translation occur in different places.
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What is a centriole? How many are there in a cell? Why is this relevant?
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A hollow tube made of nine triplets of microtubules. There are two set at right angles, a diplosome. They are at the center of a dense sphere from which microtubules radiate. How the cell stays round, how proteins can be shuttled towards the center or towards the membrane.
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When a lysosome digests an organelle? When it eats the entire host cell?
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Autophagy. Autolysis.
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12 elements of ultrastructural cytology
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1. Plasmalemma 2. Cytoplasm 3. Nucleus 4. Cytoskeleton 5. Centrioles 6. Mitochondria 7. Golgi 8. Ribosomes 9. ER 10. Lysosomes 11. Peroxisomes 12. Inclusions- lipids, glycogen, pigments and those random crystals
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Are there ribosomes in the mitochondria?
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Yes, weirdly.
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When mesenchyme becomes an osteoblast and then an osteocyte, what's happening?
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Differentiation
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What is the point of the often "prominent" nucleolus
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Production of ribosomal RNA.
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The 3 lipids found in biological membranes
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Phospholipids, cholesterol, glycolipids
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The most important characteristic of lipid bilayers?
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Fluidity. Cholesterol decreases fluidity. Unsaturation increases fluidity. Flip-flops, while a type of lipid movement, are rare. They can be stimulated by flippases.
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Why is selective flip-flopping of membrane proteins or lipids in the bilayer so important?
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Because, a protein in the outer leaflet in an organelle, if it's packaged and sent to ANY OTHER MEMBRANE, will ALWAYS wind up in the outer leaflet of that membrane. Unless an enzyme flips-it.
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Molecules found in outer leaflet and why?
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Phosphatidylcholine, sphingomyelin, glycolipids (uncharged!)
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Molecules found in inner leaflet and why?
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Phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol (charged!)
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Are there ever glycolipids on the inner membrane?
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No, never.
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Where is a glycolipid made? (Where is the sugar added?)
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Golgi. Therefore the asymmetry has to be established there before transfer to the cell membrane
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How is a protein inserted in the cell membrane?
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Via the signal mechanism that tells the cell to translate the protein inside the ER, as opposed to freely in the cytosol. Then it will be packaged in a vesicle and sent to the membrane.
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Two most common secondary structures of transmembrane protein segments.
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Alpha helices and beta barrels (wide channels, i.e., aquaporins)
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Purpose of the anion exchanger protein AE1 on RBCs?
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Gee, could it be switching Cl for HCO3?
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Protein that maintains concavity of RBC? Proteins that attaches THAT protein to membrane?
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Spectrin. Ankyrin
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What is the glycocalyx?
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Carbs of glycolipids, glycoproteins, and proteoglycans. ALL ON noncytosolic side.
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In a freeze-fracture, which side will contain the bumps? The pits?
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P face. E face.
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Defintion of osmotic pressure
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The pressure required to stop pure water from flowing into a solute-containing solution when there is a permeable membrane between them.
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Primary active transporter
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Na-K-ATPase
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Flow of ligand-protein distribution in a plasma membrane
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Homogenous distribution -> patches or clusters of complexes (passive) -> capping of ALL complexes in one region. (ATP)
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The Frye Eddin Experiment
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A fusion of mouse and human cell , with random proteins in both. After a few minutes, due to universal membrane fluidity, the proteins had been homogenously distributed.
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What are the 4 purposes of cell surface specializations?
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1. Protection
2. Cell-Cell recognition 3. Cell reception 4. Cell-Cell adhesion |
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4 types of cellular adhesion molecules
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1. N-Cams - neural cell adhesion molecule
2. Cadherins 3. Integrins 4. Selectins |
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Characterize a cadherin
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A calcium dependent adhesive glycoprotein, present in ZA and desmosomes. CELL TO CELL JXN.
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Characterize an integrin
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CELL TO ECM JXN. Recognize RGD. Examples of linkers include fibronectin or laminin.
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Characterize a selectin
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TRANSIENT CARBO CELL TO CELL JXN. Think about the epi slowing down a WBC near the site of infection.
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Critical difference between steady-state and equilibrium
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Equilibrium is a true state of NO FlOW, whereas steady-state is a highly-energetic maintenance of solute balance.
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What is the exchange catalyzed by Na-K-ATPase?
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3 Na kicked out for every 2 K pumped in.
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The Nernst potential for K? Na? Cl?
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-90. +70. -60.
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General flow equation.
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Flow = [] * Mobility * Area * Driving Force
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What is Fick's Law? Is there a way to just rationalize it? What does Einstein's Law mean in these terms?
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Flow (J) = -DAdeltaS/delta X. Basically a molecule will flow down it's concentration gradient but it doesn't like to go far. In fact, the speed of flow will decrease by a proportion of the SQUARE of the distance. So it will take glucose a hella long time to travel a meter, and forever to travel 3 meters by itself.
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What's the Vant Hoff Relation?
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Long story short, it defines osmotic pressure, which is what water exerts on a membrane when there is a difference of solute concentration on either side.
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Define macroscopic neutrality. Microscopically?
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The number of cations in a given region will equal the number of anions. But there are really water molecules in between the cations and anions, so there is a charge separation.
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What does the Nernst potential mean?
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As an ion flows across the lipid bilayer, it will change the electrical potential of the membrane towards a value determined by it's diffusive and electrical forces.
i. Since concentrations can't really *change* in the body (there's so much!), the diffusive forces are pretty constant. ii. So the Nernst potential for certain common ions, like Na, K, Ca, etc, are pretty constant based on a resting physiological membrane value of -60mV. |
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What's the problem with the Nernst potential? How do you fix that?
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It only takes into account one ion flowing at a time, but we know there are lots of diff. ions flowing across the membrane at once. A complicated derived equation involving the individual ratio of ionic resistances to total resistance and the Nernst potentials of each ion ALL ADDED TOGETHER FORGET IT.
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Physiological osmolarity. If I say there's 150mmole of NaCl in solution, what's the osmolarity? If I say 100mmole of glucose? why?
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300mOsm. 300mOsm (150mOsm Na + 150mOsm C1). 100mOsm (glucose cannot dissociate--if it cannot dissociate, the osmolarity is equal to the concentration)
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I have a solution of 150mM NaCl outside the cell and a solution of 200mM NaCl inside a cell. What's going to happen to the cell?
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The cell is in a hypotonic solution. Water will flow from the outside to the inside (water flows towards concentrated solutions). The cell will swell and lyse.
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I have a solution of 200mM NaCl outside the cell and a solution of 150mM NaCl inside the cell. What's going to happen to the cell?
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The cell is in a hypertonic solution. Water will flow from the inside of the cell out. The cell will shrink.
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How does a cell maintain volume?
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Pumping cations every which way because they are impermeable, while the anions are too permeable...
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Do steroids have a permeability coefficient that affects their flow?
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Trick question. No of course not. Their permeability coefficient would be one, because they are
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What is the term for a molecule that binds and turns ON signaling? What is the term for a molecule that binds and turns OFF signaling that was already occuring? What is the term for a molecule that binds to prevent anybody else from binding? What is the term for a molecule that binds and produces an eeny-weeny response?
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Agonist. Inverse agonist. Antagonist. Partial agonist.
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Define efficacy and affinity.
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Efficacy: a drug increases the maximal effect (Vmax is higher)
Affinity: a drug works with higher effects at lower concentrations (curve will shift to the left) |
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Efficacy + affinity =
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Potency
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Define specific and nonspecific binding
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Specific: The drug binding to it's receptor (the classic sigmoidal curve). THIS SATURATES
Non-specific: The drug that doesn't bind (This will increase linearly with increase [drug]). NON-SATURATABLE. |
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What 3 amino acid groups do kinases phosphorylate? Why?
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Serine, threonine, and tyrosine. They have OH groups.
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What do ALL non-competitive inhibitors do?
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Reduce maximal agonist response.
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The more specific a drug...
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...the steeper its binding curve.
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What do PKC and PKA have in common?
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They phosphorylate serine/threonine.
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Two forms of glycogen and what do you need to remember about this?
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Alpha rosettes and Beta granules. You can't see beta granules under LM.
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The three main pigments and KNOW about them?
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1. Lipofuscin: yellow, residual bodies of lysosomes.
2. Melanins: eumelanin is brown, tyrosine derived, you're looking at epidermis. 3. Hemoglobin (heme): hemosiderin in spleen and bilirubin in feces: bile pigment. |
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3 ways a cell moves proteins across INTRAcellular membranes?
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1. Gated transport (NPC, GTP)
2. Protein translocators (ATP) 3. Vesicular transport (ATP) |
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Proteins made in the cytosol go to three places.
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Mitochondria, nucleus, peroxisomes.
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Proteins made in the ER go where?
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Lysosomes, PM, ECF, secreted.
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Do I really need to review translation here?
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No, but KNOW: translation on a free ribosome will start, then STOP if the protein is supposed to be packaged.
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How does the cell know when a protein needs to be destroyed?
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Ubiquitin.
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Protein in mitochondrial membrane that makes it impermeable to ions?
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cardiolipin.
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You see a mitochondria with tubular christae? There's lipid droplets and smooth ER everywhere?
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Steroid producing cell.
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Contents of inner mitochondrial membrane? Contents of the matrix?
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1. ETC, ATP synthase, succinate dehydro.
2. TCA enzymes, B-oxidation enzymes, mitoDNA, RNA, Ca, Mg. |
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The enzyme catalase?
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Breaks down peroxide.
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What happens when lamins are phosphorylated? Dephosphorylated?
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The nuclear envelope will disintegrate (cell division). In telophase, when the lamins are dephosphorylated, the nuclear envelope will reform.
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How is a protein signaled for mitochondria import?
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It has a long positive signal at N-terminus.
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What is on a vesicle whose contents are regulated secretory? Constitutive secretory? Vesicles going back and forth among intracellular membranes? A vesicle that's being endocytosed to an endosome?
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Clathrin. Coatamer. Coatamer. Clathrin. CLATHRIN SAYS, "REGULATE THE HELL OUT OF ME. TELL ME WHEN TO LEAVE AND WHEN TO COME IN."
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Why did Dr. Ream make such a big deal about glycosylation occuring in rER and Golgi?
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RULE: If a protein is glycosylated, it is leaving the cell. IT MUST LEAVE. NO GLYCOSYLATED PROTEINS CAN STAY IN A NEGATIVELY CHARGED CELLULAR ENVIRONMENT. If a protein is in the Golgi or rER, it's leaving. Therefore, that's the only place glycosylation *can* occur.
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SRP in ER membrane +
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8 small hydrophobic amino acids in new protein = docking on ER membrane.
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Is a transmembrane protein made that way at the plasma membrane?
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No, it's made that way in the ER membrane, then shuttled to PM.
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What keeps a protein in the rER
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KDEL.
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If a protein has its mannose attachment (from the rER) phosphorylated in the Golgi, where is it going?
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Lysosomes.
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What is required for regulatory vesicles to move to the plasma membrane?
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Ca (you know this! neurotransmitter release!)
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Lumenal pH of lysozomes.
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5.0, maintained by ATP-dependent proton pumps.
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What happens when a lysosome merges with a phagogome, or an autophagosome, or a pinosome?
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It becomes a secondary lysosome.
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Flow lysosomal enzymes from Golgi
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Clathrin-coated vesicles -> late endosome -> mannosereceptor rebuds back to golgi -> bud decreases pH from 6.0 to 5.0 -> late endosome becomes lysosome.
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What's the point of an endosome?
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A complex that has been ENDOcytosed will be disassociated into ligand and receptor at the low pH. The receptor can be recycled to membrane, while the contents are digested.
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The difference between COP I and COP II coated vesicles?
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COP I are going towards the ER, while COP II are going towards the TGN or PM in constitutive secretion.
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Microfilaments
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F-Actin helices made of G-Actin (ATP dependent) monomers
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Stress fibers
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Bundles of actin (via a-actinin) that individually connect to an integrin, and therefore ECF proteins like fibronectin. Assists cell in exerting tensile force on ECF.
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Protein that makes up microtubules
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Tubulin monomers (GTP, Mg)
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Directionality of kinesin and dynein
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Kinesin moves towards periphery, dynein towards the centrosome
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Core of the cilium
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9 peripherary microtubule doublets around a pair of unjoined microtubules. 9 + 2
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Movement of cilium? Flagellum?
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Metachronal. Quasi-sinusoidal.
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Keratin
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IF of epi, hair, nails
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Vimentin
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Mesenchymal cells
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Desmin
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Muscle cells
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GFAP
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Astrocytes and Schwann Cells
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Lamins
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Everything with a nucleus.
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Filaggrin
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IF binding protein - binds keratin into tonofilaments.
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Zonula Occludens
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The fancy name for a tight junction. Contain claudins and occludin. Anchored to the actin skeleton.
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Where is the fascia occludens?
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Between capillary endothelial cells
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How do the cadherins in a zonula adherens interact with actin?
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The catenins. CALCIUM-DEPENDENT
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What are the protein components of a desmosome?
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Desmin filaments in cardiac muscle; keratin filaments or tonofilaments in epi. Desmoplakins, plakoglobin. etc etc. CALCIUM-DEPENDENT.
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What is the terminal bar?
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The LM resolvable complex of ZO and ZA
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Difference between a desmosome and an hemidesmosome
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The IF filaments run lateral to the desmosome plaque, while they terminate in a hemidesmosome.
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Pores in gap junctions
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Connexons
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