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| Smooth ER in the liver (hepatocytes) |
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Cuts up glycogen, exports glucose to the blood with GLUT2
Drug hydroxylation |
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| Long sheets of the Rough ER and Golgi |
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| Golgi's nucleus facing; membrane facing sides |
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| Movement of lipids and enzymes through the Golgi |
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| Stationary cisternae with transition vesicles moving in both directions, or maturing cisternae for larger proteins that shift to the trans face |
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| Carbohydrates (among other things) are added (and removed) as proteins move anterograde through the Golgi |
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| In the direction of the plus end, or towards the cell membrane. |
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| In the direction of the minus end, or towards the nucleus. |
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| Have no membrane proteins, as the contents are dumped outside the cell and not integrated into the cell membrane. |
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| Can move in either direction, to mature, fuse or be digested. |
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| A state of vesicle development wherein a late endosome either acidifies on its own or fuses with a lysosome. |
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| A state of vesicle development wherein an early endosome matures on its own or fuses with another vesicle in order to mature. |
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| When a cell cannibalizes its own organelles by creating a membrane around it and fuses this with a lysosome, as in maturing red blood cells. |
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| The opposite of secretion, wherein the cell takes in material by creating an invagination, squeezing to form a neck and then cutting the sealed membrane loose from the cell membrane. |
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| Large scale endocytosis performed by amoeba to eat as well as by macrophages, dendritic cells and neutrophils in the human immune system. |
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| Ever present shallows to which membrane receptors move on binding, whereupon more clathrin is recruited to create an invagination before the membrane fuses and is cut to form a vesicle. |
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| Triskelions which polymerize to form hexagons and pentagons as a net, like a soccer ball. |
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| Tethering complexes bind to vesicle receptors, then draw the vesicle in so that it can bind snare proteins with the membrane. This forces the membranes together then triggers a GTPase to open the joined membranes. |
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| Not part of the ER-Golgi system, responsible only for dealing with hydrogen peroxide. |
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| Can gather parts directly from the cytoplasm or divide into two fully developed peroxisomes. |
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| α and β tubulin as heterodimers. |
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| Proceeds in a spiral one αβ heterodimer at a time at a sigmoidal speed. May proceed in both directions, but usually from the (β) plus end. |
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| 13 protofilaments around a 15nm hollow core. Usually in a 13 singlet, 13+11 doublet or 13+11+11 triplet. |
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Tubulin bound to GTP at the N-terminal, probably for stabilization of the microtubule. Hydrolysis causes maturation, but is not necessarily required.
This is the dynamic instability model. |
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| MicroTubule Organizing Center, often the centrosome, from which microtubules grow. |
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| A circle of 13 microtubule triplets, which produces less complex TuRCs to encourage the growth of normal microtubules. |
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| γ-Tubulin Ring Complexes which form in a circle and grow normal αβ microtubules. |
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| A plant derived poison which binds to the middle of β tubulin and inhibits microtubule growth. |
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| To move large structures such as organelles through the cell and create a polarity seen in axons, cilia, RBCs, etc. |
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| G-(globular)-actin, which forms two strings that make up F-(filamental)-actin. |
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| Similar to growth in microtubules, but with ATP caps instead of GTP. Can only proceed in the plus direction. |
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| Provide structure in stress fibers (sarcomeres), cell cortex (membrane regulation), filopodium (motility 'foot' with straight bundles), lamellipodium (branched actin for adhesion in motility) and microvilli (for absorption, secretion and cell adhesion) |
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| Regulators which shut down microfilament alteration in the absence of GTP. |
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| Intermediate filament subunit |
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| Various proteins, which form dimers that stack head-to-tail in tetramers to form protofilaments and then intermediate filaments in groups of 8. |
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| Microtubule motors with a heavy chain, cargo-binding light chain and ATP binding head which steps forward on hydrolysis. Responsible for moving anterograde. |
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| Microtubule motors with cargo-binding dynactin complexes and an ATP binding head in the shape of a wheel which cocks on hydrolysis. Responsible for moving retrograde. |
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| Motor proteins which move cilia and flagella. The basal body consists of 9 microtubule triplets. The axoneme consists of 9 microtubule doublets around a singlet pair. Outer tubules are connected by covalent crosslinks while the dyneins create motion. |
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| Microfilament motors with a double globular actin-binding head (esp. Myosin II), one or two heavy chains and a tail. Make up the thick filaments of sarcomeres. |
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| Sarcomeres contract as myosins "walk" along actin, pulling the ends together. Sarcomeres exist in a grid that makes up a vertical unit of myofibrils. |
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| Myosin-actin binding mechanism |
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Definition
| When ATP binds, one myosin detaches. On hydrolysis the mysosin cocks and can now bind to actin. It "shoots" when the detached phosphate releases. ADP is then released so that a new ATP can bind. |
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| Calcium regulation in sarcomeres |
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Definition
| Muscle cells have a specialized ER called the SR which stores and releases calcium, interconnected to T tubules which are connected to neurons. On the neuron's signal, depolarization tells the SR to release calcium and allow contraction. |
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| Cardiac muscle specialization |
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Definition
| Instead of fused cells forming a string, these muscle cells are connected head to tail by intercalated disks. The cells branch, and contain plenty of mitochondria for energy. |
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| Smooth muscle specialization |
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| Internal organ muscle is made up of individual oblong cells with muscle fibers spaced out in the middle. Dense bodies are connected in a net by intermediate filaments regulated by Calmodulin instead of an SR. |
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| Actin filaments in lamellipodia and filopodia polymerize to grow, and once adhesion proteins attach the cell membrane to outside subtrate they detach from the trailing edge and actin contraction moves the trailing edge toward the leading edge. |
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| Macrophages and Dendritic Cells |
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| Sister cells which both develop from a monocyte that circulates in the blood. They both stay in tissue, don't circulate through blood and are functionally equivalent, but dendritic cells are only there to recruit lymphocytes. |
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| To engulf and destroy pathogens, release inflammatory mediators and tag antigens for other immune cells. |
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| To engulf pathogens via endo- or phagocytosis, release reactive oxygen and nitrogen, then lyse to form extracellular bacteria traps (this is what puss is). |
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| Macrophage identity-determining receptors |
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| Identify bacterial compounds or complement protein as "other", but also host cell ligands in order to prevent phagocytosis of "self" cells. |
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| Macrophages release cytokines which bring fluid to the infection site (to prevent the pathogen from spreading), tell the brain to increase body temperature and respiration, recruit neutrophils, but also decrease blood pressure. |
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| Live in bone marrow, have an unusual nucleus shape, and work much like macrophages but in much larger numbers. |
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| The antigen is phagocytosed into a phagosome. Granules fuse to the basic phagosome to kill the contents. This acidifies the phagosome, causing lysosomes to fuse and digest the remnants of the antigen. Once the granules are depleted, the neutrophil lyses to form an extracellular bacteria trap. |
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| The process by which neutrophils leave the bone marrow and squeeze between the sides of two blood vessel using lamellipodia and filopodia. |
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| Once neutrophils are in the tissue they crawl through the basement membrane and connective tissue, secreting lysosomal enzymes to digest the protein matrix. |
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1. Macrophage sees pathogen
2. Phagocytoses pathogen, induces inflammation
3. Neutrophils leave marrow and extravasate
4. Neutrophils and macrophages continue phagocytosis to completion |
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| The glue that surrounds cells, linking cells to cells and those bonds to the actin cytoskeleton. |
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| Spot-welds between cells, making use of cadherins (desmocollin and desmoglein) and adaptor proteins (plakophilin, plakoglobin and desmoplakin) which connect to intermediate filaments rather than microfilaments. |
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| Similar to desmosomes, but attaching cells to the basal lamina rather than each other. |
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| Essentially impermeable junctions between cells which keep food and other undesirables away from connective tissue. |
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| Channels for ions, nutrients and signals, typically about 3nm per opening. |
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| A protein complex fiber which forms a triple helix that repeats in a staggered pattern of fibrils, creating a stripe patten. |
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