PCB2099Cell&TissueFunction-Student NOTES - Eukaryotic cell TRUE membrane bound nucleus Mitosis Replication of daughter cells Basic unit of all

PCB2099Cell&TissueFunction-Student NOTES - Eukaryotic cell...

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Unformatted text preview: 9/23/15 Eukaryotic cell: TRUE membrane bound nucleus Mitosis: Replication of daughter cells • Basic unit of all multicellular organisms • Smallest structural unit producing all vital functions • Pre-existing cells produce cells • Cell Membrane • Cytosol cytoplasm / Plasma membrane: seperates ICF from ECF (intra/extra cellular fluid) Fluid matrix • Organelles • Inclusions Cell's mini organs inclusion bodies: describes the chemical constituents of t he cytoplasm • Physical isolation: Extra/intracellular barrier • Regulation of exchange of substances • Sensitivity:Affected by changes in extracellular fluid; receptors for recognition and communication; alterations affect physiology • Structural support more receptors on membrane causes greater snsitivity 1 No ATP required. i.e. diffusion- the movement of particles from an area of high concentration to low concentration • Diffusion • Osmosis No ATP required; movement of FLUIDS (WATER) across the plasma membrane • Filtration-Hydrostatic pressure forces water across membrane; solutes selected according to size. • Facilitated diffusion carrier proteins that are integrated into the plasma membrane They create channels that facilitate diffusion into and out of the cell substances that use active transport • Active transport-Na, K, Ca, Mg • Endocytosis-phagocytosis, pinocytosis "cell eating/ drinking" invagination of the plasma membrane occurs because of the change in shape bacterium Exocytosis: secretion of substances from the cell. i.e. macrophage (WBC) ingulfs the bacteria and the lysosome fuses to the phagosome. Bacteria is phagosome digestd and the phagosome migrates to plasma membrane and rids f all biproducts of bacteria. solution=solute + solvent for bacterium the plasma mEmbrane pull away frim walls of bacteria --PLASMOLYSIS • Selectively permeable: CAUSES WEAKING OF BACTERIA (TOOTH INFECTION EXMPLE) hypertonic higher solute concentration outside causes water to seep out of cell. WATER EFFLUX, causes shrinkage of cell (CREAMATION: Shrinking due to water loss in hypertonic medium) ecf solute concentration > ICF Bacterium: isotonicEqual no bursting occurs b/c there is a CELL WALL (RBC amount of concentration inside vs outside. No net movement b/c all is balanced. is happiest here (: ) hypotonic increase of concentration inside than outside.(solute) water goes into cell- WATER INFLUX, Bacterium will become TURGID (firm) LYSIS: bursting of cell because of threshold TURGIDITY: IDEAL MEDIUM for a bacteria cell. reaching max. hemolysis: bursting of rbc b/c of influx of water. Solute: salt, Solvent: water 2 • The cellular material between the plasma membrane and nucleus;site of most cellular activities. Electronmicroscopy (EM) • EM has revealed that it consists of cytosol, organelles, and inclusion bodies. FLuid matrix is everything in between the organelles • • • • • • Viscous, semitransparent fluid substance Complex mixture of salts Dissolved proteins (enzymes) Amino acids monomers of proteins Lipids Low carbohydrate [ ] • Non functional units/chemical substances • Glycosomes-hepato and myocytes Glycosomes- specialized components storage product is GLYCOGEN (storage olysacchrides) i.e. hepatocytes- liver cells, myocytes- muscle cells • Lipids-adipocytes lipids is biomolecule for adipocytes --> found in the adipose tissue 3 • Specialized cellular compartments • Non membranous- cytoskeleton, centrioles, ribosomes, cilia, and flagella. • Membranous- mitochondria, peroxisomes, lysosomes, nucleus,endoplasmic reticulum, and Golgi apparatus. • Intracellular network that supports cell’s structures & providing machinery to generate various cell movements • Four major components:microtubules, microfilaments, intermediate, and thick filaments. (the largest) • Thinnest elements of the cytoskeleton • Primary protein: actin • Forms dense cross-linked network under cell membrane • Involved in motility or changes in cell’s morphology. The cell's overall shape 4 • Anchors cytoskeleton to integral proteins. proteins that are embedded in the plasma membrane • Adheres cell membrane to underlying cytoplasm. acts as a cellular glue • Responsible for amoebid movements and membrane changes accompanying endo/exocytosis. • Elements with largest diameter; spherical protein subunits (tubulin);determine cell’s overall morphology and organelle distribution. Amoebid movements: a cell hat can change/transform entire shape into that of an amoeba. includes the extension of the cytoplasm, allows for motility of the cell. "tiny rails that allow movement from point A to point B. • Functions as primary component of cytoskeleton/anchor organelles; can adhere to organelles for intracellular movement movement via motor proteins "think rails between the cell" • Form structural component of cilia, Cilia:hairlike things Flagella: elongated versions of the cilia. flagella, and centrioles. Centrioles are evident during cell division • Motor proteins (kinesins & dyneins) are mainly responsible for repositioning of attached to some organelles and allow for intracellular movement organelles along microtubules. move towards nucleus/ plasma membrane 5 • Microscopic, finger-shaped projections of membrane; increase surface area (absorption) (jejunum/ileum, kidneys). • Small, barrel shaped oriented at right angles to each other (nine triplets); evident during cell division; form bases; lacking in osteocytes/mature RBCs osteocytes: mature bone cells AKA brush border of the cell. increase S.A to allow for ample absorption Found in the jejunum area (small intestine/ kidney cells -->especially in the convoluted tubules) 9 trilets of microtubules, nothing in the center found during cell division anchoring mechanism for the cilia 9 pairs of micro-tubules around center and center has only 2 micro-tubules • Contain nine groups of microtubule doublets surrounding central pair (9+2) • Basal body anchor basal body- centriole anchors cilia to plasma membrane • Exposed aspect of cilia covered by membrane and “beat” rhythmically • Propel substances across cell surface i.e. in trachea/ windpipe --cilia ensures particles get trapped and are transported to the pharynx area, especially in colds in lungs/ bronchi Air trapped with mucus will move away from the lung tissue • Substantially longer projections (compared to the cilia) • Propels cell involved in cell motility spermatazoa are flagellated • Small, dark staining granules composed of ribosomal RNA • Two globular subunits (small, large) • Free ribosomes produce soluble proteins that will function in the cytosol • Membrane-bound (fixed) ribosomes synthesize proteins destined for cellular membranes or cellular export. attached to the rough E.R. membrane 6 inner membrane is the site of ATP synthesis, also has enzymes fothe krebs cycle • • • • • Threadlike, double membraned organelle Inner membrane forms cristae (ATP) Cristae are infoldings. Space within the Cristae is the MITOCHONDRIAL MATRIC. Number may vary according to cell type cells requiring more energy will have more mitochondrias DNA/RNA MITOCHONDRIAL MATRIX is where Cellular respiration the Krebs Cycle occurs 1. Glycolysis: Splitting of the sugar into 2 PYRUVATES (10 steps) 2. Krebs cycle/ citric Acid/ TCAA [occurs in the MITOCHONDRIAL MATRIX] 3. Electrontransport Chain- this is where the most ATP is harvested. ECF ICF GLYCOSIS STEPS CYTOSOL (enzymes are currently floating around) The enzyme HEXOKINASE attacks and break down the glucose as it enters the cell -performs GLYCOLYSIS--the splitting of the cell (10 step process) -results in 2 (3c) PYRUVATE YEILDS 2 ATPs Plasma membrane mitochondrial membrane As the pyruvate tries to enter in the mitochondrial membrane it will lose 1 carbon, 2C (ready to enter the result is a 2 carbon compound and this is what is needed to get into the mitochondria. mitochondria). then... loses 2 ATPs during Krebs Cycle (entering mitochondrial matrix) -->0ATPs In the matrix of the mitochondria is the kreb cycle (3C) (3C) Pyruvate KREBS CYCLE STEPS (inside mitochondria (mitochondrial matrix, per glucose molecule)) 1.CITRATE (6C) 2.Isocitrate (6C) 3.Alpha-Ketaglutarate (5C) 4.Co-Enzyme A (4C) 5.Succinate (4C) 6.Fumorate (4 C) 7.Malrate (4C) 8.oxaloacitate (4C) The pyruvate is currently 2C, which will join with oxaloacitate (4C) 2C+4C=6C compound CITRATE Electron Transport Chain gives 34 Krebs Cycle results in 2 ATPs. (2-2+2=2 ATPS) ATPs. 2+34=36 ATPs (yielded) TOTAL in a Eukaryotic Cell per glucose molecule. Electron transport chain is occurring in the inner mitochondrial membrane. 7 Nucleus is double membraned* Osteoclasts: special bone cells that are involved in the break down of bone tissue (multinucleated) Hepatocytes: liver cells (some) myocytes: muscle cells (multinucleated) RBCs matured Mammals have no nucleus • Gene containing control center • Controls synthesis of proteins • Numbers vary: (osteoclasts, hepatocytes, myocytes, RBCs) • Shapes vary: spherical,elongate conforms to shape of the cell • Has three distinct regions: nuclear *double membrane nuclear envelope, core of the nucleus -nucleoli, site of envelope, nucleoli, and chromatin. condensed genetic material is the chromatin everything from the membrane of the nucleus to the nucleus is the NUCLEOPLASM (similar to the cytoplasm of the cell) • Dark staining spherical bodies located within nucleus responsible for ribosomal production • Non-membrane bound • Typically one or two per cell • Subunits assembled subunits of the ribosomes the genetic information that is condensed in the nucleoplasm of the cell • Composed of equal amounts of DNA and globular histone proteins • Chromosome-condensed chromatin coils forming short “barlike” bodies. 8 • Network of intracellular membranes and cisternae cisternae: the foldings • Functions: (1) Synthesizes carbohydrates, lipids, and proteins; (2) Transportation transportation of substances w/i the cell or the E.R. Regions of the E.R • Manufactures secreted proteins ribosomes are attached to the Rough ER • Continuum of RER • Lipid metabolism and synthesis/cholesterolsteroid synthesis • Absorption/transport lipids-detoxification detox of the cell • Principal “traffic director” for cellular proteins • Modifies, concentrates, and packages "think the UPS of cell" • “Receiving” side is cis face, “shipping” side cis face recieves w/e is produces or secreted is trans face • Secretory vesicles pinch off from trans face and fuse to membrane. 9 endocytosis: active process that can occur at cellular membrane. • Digests particles taken in by endocytosis • Degrade worn-out or nonfunctional organelles/break down nonuseful tissues • Metabolic functions: glycogenolysis; metabolic functions: involved in glycogenolysis--breaking down of glycogen into releasing of ThyH from thyroid cells useful glucose • Breakdown of bone to release Ca ions osteocytes have alot of lysosomes to breakdown blood tissue and release Ca. *pinching off of gogli will fuse to cell membrane aka MICROBODIES, found in high #s in the hepatocytes and liver cells -->heavily involved in detoxification. • Membranous sacs containing powerful enzymes(oxidases/catalases) • Oxidases use O2 to detoxify alcohol and formaldehyde • Numerous in hepatocytes and kidney cells • Self replicating/do not arise from Golgi apparatus Notes from the Video: "Life of a Cell" Lipid raft: found in plasma membrane Actin filaments: components of the cytoskeleton, small in diameter compared to microtubules, constantly being rearranged to conform to the shape of the cell. Microtubules: organizing center that puts microtubules together motor proteins moving along microtubule. Mitochondria: involved in Kreb's cycle Centriole Pores: found at the surface of the nucleus Ribosome: smaller & larger subunits • Tissues are groups of cells w/common and related functions. • Primary tissue types: Epithelial(covering),Connective(support), or layer Muscle(movement), Neural(control). /nervous tissue somatic/ visceral (i.e.walls of blood vessels/ guttube) 10 • Occurs in the body as: Covering, lining, glandular epithelium glandular epithelium: secretory cells form them. • Functions include: Protection, absorption, filtration,secretion. Protection: stratified (1+ layer thickness) absorption: microvilli, increase in surface area filtration: creates a siv secretion: cells that embark on exocytosis • Composed of close packed cells; tiny amount of extra-cellular material in narrow spaces between them. not alot of space amoung them • Specialized contacts-Form continuous sheets; junctions junctions: four type, 1. tight junction: heavily involved in creating barriers, close to the apex/ top of cell 2. adhering junction: anchoring 3. desmosomes: achoring/ reinforcement of cell 4. gap junctions: open communication between neighboring cells, particles movving from one cell to the other. • Apical surface, lateral, base Apical: the top of the cell lateral: to the side base: bottom, always placed on some type of basement membrane/ platform [BASAL LAMINA]--the platform where the cells are placed. • Number of layers: Simple(single cell) simple: 1 cell thickness, purpose is for absorption, filtration, or thin barrier 1+ cell thickness is found in areas of abrasion (friction) layer for absorption, filtration, & thin barrier. Stratified (two or more)layers common in high abrasion areas. • Shape: Squamous, Cuboidal, Columnar squamous: width>heighth cuboidal W=H columnar heigth> width *nucleus always conforms to the overall shape. round spherical nucleus vertical nucleus flat nucleus 11 • Simple Squamous- Cells laterally flattened; located in areas of filtration/rapid diffusion. Endothelial lining-provides frictionless lining; blood vessels/heart chambers. innermost lining of the blood vessels, chambers of the <3. -very fragile b/c they are only 1 layer thick H.I that can occur is mesothelium: a simple epithelium that lines indiv. organs, one exposed to chronic asbesthos can develop MESOTHELIOMA. • Simple Cuboidal-Spherical nuclei; absorption & secretion; kidney tubules and i.e. proxial convoluted tubules & discoconvolated tubules. (PCT & DCT) secretory ducts. • Simple Columnar-Single layer of tall cells aligned in rows;some have cilia;absorption & secretion. cilia at the apex (hairlike, purpose is to move things across surface) • Pseudostratified Columnar- Cells vary in height; absorption & secretion; trachea. has the appearance of stratification but is NOT b/c each cell is connected to the basal lamina. Found in the lining of trachea (aka windpipe) • Stratified Squamous- Most widespread (in areas of wear and tear);superficial cells less viable than deep cells. superficial cells are dead (get sloughed off) & deep cells are germinitive (constantly forming new ones) • Stratified Columnar- Rare tissue; forms large gland ducts transitional is for the urinary system. i.e. distended (stretched) then the cells at the top will flatten out, but basal cells always maintains shape regardless of the shape of the organ. • Transitional- Basal cells are cuboidal/colum., when the organ is relaxed the apical cells will become dome apical cells vary in shape according to distension shaped. of organ; urinary bladder. transitional/ urothelium apical cells (cells at the top) 12 Living component (cellular component of CT), w/e is outside constitutes as NONliving, i.e. ECM (extra cellular matrix) *connective tissue is NEVER exposed. Exposure = lesion • Found throughout entire body but never exposed. • Classes : (1)Connective tissue proper (2)cartilage (3)bone (4) blood. cartilage/ bone is supportive connective tissue blood is a fluid connective tissue • Functions: (1)binding/support (2) protection (3) insulation (4) transportation. 1. binding, i.e. ligaments- bind together bone to bone 2. protection, i.e. bone tissue 3. insulation, i.e. adipose tissue 4. transportation, i.e. blood • Have common origin all are derived from mesenchyme-->stem tissue • Varying degrees of vascularity i.e. cartilage has no blood supply, but bone is very vascular (good amnt of blood supply) • Extracellular matrix: separates living from non-living material; bears weight, withstands tension,& endures physical trauma. CT is more resilient than epithelial tissue. • Loose Connective Tissue Areolar- Most widely distributed CT; supports and binds other tissues,reinforces organs, stores nutrients. adipocytes (fat cells), nucleus is displaced w/ lipid droplet Adipose- Adipocytes predominate(90%), oil droplet occupies cell volume displacing nuclei; tissue vascularized; insulation & shock absorber. good amount of blood vessel. shock absorber/ cushion for organs 13 *ir/regular describes the arrangement of the collagen fibers in the matrix • DENSE CONNECTIVE TISSUE arrangement of... Dense regular-Parallel collagen fibers/ poorly vascularized; enormous tensile strength; found in tendons, ligaments. Dense irregular:Irregularly arranged collagen fibers, found in dermis, fibrous coverings of kidneys, bones, cartilages, muscles, and nerves. All made of dense irregular connective tissue: kidneys: renal capsule bones: periosteum cartilage: perichondrium muscles: perimysium nerves: covered by perineurium dermis is considered as the 2nd skin, if you were a cow after the fur is removed this would be considered the "leather" Cartilage • Chondroitin sulfate grand substance for cartilage, available in supplements, considered as a supplement for joint health • Withstands tension & compression • Flexible, avascular and lacks nerve fibers. avascular in the matrix of the CT • Predominant cell types: chondroblasts, "-blasts" alludes to immature cell chondrocytes. chrondroblasts mature to chondrocytes (cartilage cell) hyaline and elastic cartilage looks similar except... Hyaline Cartilage rigid fibers • Most abundant cartilage. • Chondrocytes (1-10%) of cartilage vol. • Located in nose, costal cartilages, tracheal rings,larynx, embryonic skeleton, and epiphyseal plates. Nose: nasal septum tracheal: c-rings inutero (embryonic) started off cartilidge and then calcified epiphyseal plates: found in long bones to elongate the long bone. (continuous until you mature and stop growing) elastic fibersElastic Cartilage • Similar to hyaline; elastin fibers gives the cartilage recoil, found in the core of the external ear • External ear and epiglottis and the trachea that diverts food to the esophagus chondrocytes are found within the lacuna 14 Fibrocartilage very resilient • Matrix dominated by densely interwoven collagen fibers • Compressible & tension resistant. found in the knee joint (2), between femor and tibia, acts as a shock absorber • Intervertebral discs,pubic symphysis, meniscus. 2 pubic bones are adjoined by these Bone (Osseous tissue) • Bone matrix similar to cartilage; more collagen fibers & inorganic salts (hydroxyapatites) • Supports/ protects softer tissue; hematopoietic;vascularized hematopoietic: involved in the production of formed elements: RBCs, WBCs, & platelets • Osteoblasts, osteocytes (produced from the marrow) cellular composition of bone tissue osteoblasts: precursor to osteocytes( bone cells), involved in bone BUILDING Osteoclasts: involved in bone LYSIS *putting back broken bones together encourages osteoblasts. AKA blood • Blood matrix is plasma, in between RBCs and WBCs • Matrix: H20, salts, proteins (blood fibers evident during clotting) • formed elements RBCs, leukocytes, platelets (aka cellular • Transportation components): transports gases, nutrients, hormones, chemical by-products • Highly cellular • Vascularized blood supply • Myofilaments (actin/myosin) (contractile proteins) muscle types: • Skeletal (striated), cardiac, smooth Cardiac & Skeletal, when observed under light microscope, they are similar b/c of visible striations. Cardiac & Smooth, similar in that they have involuntary contractions, controlled by the automatic nervous system 15 Skeletal muscle • Striated • Attached to bones • Somatic movements general body movements • Large multinucleated myocytes (myocytes=muscl...
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