Cell Biology: Prokaryotic Cell Structure PDF

Ch. - prokaryotic cell structure Cells are the Gundamental Units of Life cells are the building blocks of all...

Ch. - prokaryotic cell structure Cells are the Gundamental Units of Life cells are the building blocks of all organisms in single-celled organisms , the cell is everything Cell Theory · An underlying principle of biology · cells are basic units of life · all living organisms are made of cells all cells come from pre-existing cells 4 Common Components 1 ) an enclosing plasma membrane separate cell interior from environment..) Cytoplasm made of cytosol in which other components are found (gel-like) 2 3. ) DNA--genetic material of cell-for prokaryotes w in nucleoid 4 ) Ribosomes - synthesize proteins cell Size varies use microscopes to see cells ; dye the cells · measured in Mm (micrometers grain of salt-60mm WBC 25mm , large surface area makes diffusion rate higher (of nutrients Waste adaptations to increase surface area microvilli/villi in the p membrane ·. RBC shape Classification : 3 Domains Bacterias · Archae -extremobiles] prokaryotes simplest cell type Eukaryota · Prokaryotic Cell characterized by : no nucleus DNA in nucleoid , , no membrane-bound organelles cytoplasm bound by p membrane. ribosomes are in cytoplasm cell membrane surrounded by cell wall (peptidoglycan) · , Master of Adaptation prokaryotes thrive almost everywhere including acidic salby cold or not , , , due to ability to adapt tr diverse habitats prokaryotes are most abundant · , chemosynthetic microbes for the base of food webs at hydrothermal vents · carbon is fixed into organisms using chemosynthesis. Hydrogen Sulphide · prokaryotic cell shapes : spherical rod spiral , , Humans · 10-100 trillion cells ainst pathogens (microbiomesdenseagocarbs of 300 different types minersasa on t in our body lives loX that many bacterial cells · in mouth alone vitamins 500 types produce · · · Antibiotics tetanus , bubonic plague , cholera Binary Fission bacteria grow to a fixed size+ then reproduce through binary fission · asexual reproduction under optimal conditions can grows divide extremely rapidly-double as 17 min. quickly as every · , Compartmentalization prokaryotic cells usually · lack complex compartmentalization some do have specializedmembranes that perform metabolic functions usually infoldings of plasma membrane One Me mb r a ne Plasma Membrane functions defining outer boarder of all cells o organelles managing what enters exits receiving external signals + initiating response adhering to neighboring cells Phospholipids Bilayer - Molecules (lipido protein) can move laterally within membrane · Fluid "Sea" of lipids : · Mosaic protein within membranes : Cholesterol maintain correct bluidity : · · on the inside of cell : , cytoskeleton cable like structures outside of the cell : carbohydrates w/ glycolipidoglycoprotein ; glycocalyx provide - identification in mult. cellular organisms protection o cell attachment cite , , · shorter o more unsaturated batty acids have a lower melting point Membrane Fluidity affected by nature of phospholipid fails cholesterol saturated shearic acid ; chains lack double bonds results in a straight structure that favors right packing : , unsaturated Oleic acid ; It double bonds that introduce kinks reduce lightness of packing (more fluid) : - Cholesterolo Fluidity amphipathicstructurechdestdaowsibachighyw phospholipidsgoesinbetweis · as temp increases , lipids become more bluid Integral Peripheral Proteins integral membrane protein : permanently associated w/ membrane o can cross entire membrane peripheral membrane proteins membrane but not imbeded temporarily associated w/ either side of : functions of proteins in Membrane : · CellMembrane-semi-permeable barrier · Transporter- doorways in memb to allow. certain substances to pass in vout of cell (channel : hot dog) ) carriers · pick up what is being transported Receptors can receive signals from other areas communicate to inside of cells · - EX Insulin insulin RECEPTOR is embedded in membranes receives signal to instruct cell to take up : : glucose · Enzyme-catalyze chemical reactions ?? · Anchor-maintaining structure/shape of cell or keep cell anchored to a specific location Evidence of Fluid Mosaic labeled w/ blourescent molecules resulting in a uniform flourescence over entire membrane membrane is , photobleaching causes a bleached area where there is no flourescence flourescence gradually returns to bleached area bc. of movement of flour proteins into area Carbohydrates zra major component - oligsaccharide carbs · located on exterior surface of plasma membrane bound to either proteins (form , glycoproteins) or to lipids (forming glycolipids) Membrane Transport selectively permeable · · Diffusion movement of molecules from : a region of high concentration - low concentration due to random thermal motion · PassiveTransport (H-L) Simple diffusion : doesn't need a channel majority are hydrophobic, go · , directly through phospholipid layer oxygen CO2 steroid lipids Gatty acids water , , , , small polar molecules can pass directly through bilayer · · facilitated diffusion : · molecules move across membrane w/ help of a carrier or channel (channels mostly used to transportions across membrane ; specific of channel for each ion) type glucose , BNY-IING with a charge (ion) · Aquaporin : water channel to speed up transport more specific molecules carriers : glucose small sugars aminos , , Active Transport ((w/l) · signals transmitted use a channel/carrier to more molecules across memb.; electrical Gets energy from ATP conformational Change : proteins triggered by certain events ex : hydrolysis of ATP. Nalk pump (moving from high zlow concentration BOTH molecules more against their - gradient) · Step 302 3 sodium ions pumped out : of cell against couc grad. - , Step 304 2 potassium ions are pumped into cell : against conc grad. - · - · Affinity : now strongly things I bond to each other low: weak high: strong , Endocytosis- Exocytosis (Secretion) · Endocytosis bring material into the cell : Phagocytosis large particle surrounded by phospholipid-vacuole : Phinocytosis small particle surrounded by phospholipid-reside : Exocytosis material moved out of the cell ala secretion : Osmosis of diffusion involving water type systems tend to move toward equilibrium ( = concentration of solute on both sides of membrane · osomolarity - similar to molarity A solute water · · moves from low to high concentration - 300mOsm 600mOsm jonicity animal cells function best when extracellular Gluids are isotonic rDc = 300 m Osmot hypotonic water goes in lysed higher insidea normalnisity 3 is · isotonic water goingin out hypertonic-water goes out shriveled tonsity is higher outside Cell Walls o Turgor Pressure · cell wall provided structural support protection plant cell bugor pressure within the cell occurs when water moves into cell through osmosis flacid limp Chypertonic) , Turgid , has structure (hypotonic osmoregulation by other organisms freshwater protists use contractile vacuoles to pump water our so they don't burst Marine Invertebraes have internal salt concentrations fish excrete urine to get rid of excess 120/salts osmoreceptors of brain cells monitor solute concentrations in our blood releasing hormones that affect Kidney , cunction sodium-potassium pump keeps the cytoplasm of rbc isotonic w/blood plasma preventing lysis of cells because it pumps out extra sal  Cell Biology vesicles membrane bound sacs that carry molecules from one compartment of the endomembrane system : to another prokaryotic cells do not have a nucleus component the fluid nature of the phospholipid bilayer allows vesicles the with different membrane ability toouce compartments of the cell entering the golgi apparatus proteins muso go through rough ER before lysosomes are organelles known for their acidic environment with a p 1 around 5 0 (ideal for digestive... enzymes lysosomes can contain high levels of enzymes that are capable of breaking down proteins nucleic acids · nucleoid location of : genetic material in prokaryotic cells · Chloroplasts Utilize CO2 as a reactant  Aerobic Respiration use O2 to make ATP · biobic End os ym one ory prokaryotic cells incorporated as organelles in early eukaryotic cell lineage Photosynthesis : CO2 Eukaryotic Cells · eukaryotic cells contain multiple organelles that do different jobs H20wGOOoye different cell types will have a unique organization of these organelles that is specialized to perform the · work of that cell type The First Eukaryotes Endosymbiont Theory : plant · chloroplasts contain green pigment chlorophyll , as well as enzymes + other molecules that function in photosynthesis · Mitochondria contain the structures s enzymes that use oxygen fuel to produce DTP during Herobic Respiration animal · nucleus : ribosome synthesis - happens in nucleolus ribosomal proteins - nucleus - small large ribosomal unit = mRNA-ribosome ; rRNA ribosomal RNA : ribosomes : protein synthesis ribosome- rRNA protein (up to 10 mil. /cell) Endomembrane System - Protein Movement consists of nuclear envelope E R golgi appara lus lysosomes Vesicles Plasma membrane · : ,.,. , , , transport vesicle comes from C R. (rough). - golgi complex - vesicle plasma membrane exits -> Cytoskeleton · enables support structure , , a movement for the cell  Ch3 403 5.. - write notes on structure + function of the organelles/structures peroxisomes in link Nucleus nuclear envelope - composed of 2 membranes , inner-outer , - defines the boundary of nucleus eachmembraneislipidbilayerWithassociatedproteins nown as "nuclear pores" outer has ribosomes attached physically continuous wher. : , · nuclear pores a protein channel in the nuclear envelope that allows molecules to more in out of the - nucleus + is essential so the nucleus can communicate wh the rest of the cell ex some proteins that are synthesized in the cytosol (transcription factors) more through n p 's -enter nucleus :.. where they then control how when genetic info is expressed transfer of into encoded by DNA depends on mRNA movement out of nucleus · through n. p. · nucleolus- location of ribosome synthesis (rRNA) URNA combined with protein (small) · ribosomes = chromatin within nucleus , made of DNA - histone proteins - can come in I different forms : Center) - · enchromatin looces expressiontranscription of DNA make different of mRND , replication types · : " , heterchromatin : Eight ; Rough ER (with ribosomes) · When going from DND- mRNA - pushed into rough e r.. · site of protein systhesis membrane , excreted lysosomes , protein folding has enzymes o can perform Ntype , glycosylation (sugar residue now proteins become activated · modifies protein by adding carbohydrates to form a glycoprotein packages proteins into transport vesicles that move-o golgi Smooth E R.. · site of fatty acid o phospholipid biosynthesis predominates - in cells specialized forproduction of lipids lipid synthesis cells that synthesize steroid hormones have well developed smooth ER that · produces large quantities of cholesterol also contains enzymes that help detoxify some lipid soluble drugs etc. go to liver enzymes detoxify liver drugs toxins , , calcium storage a pumps out when needed Golgi Apparatus next stop for vesides that bud of ER (carry lipids protein) cis face receives biosynthetic lipids modified - delivered to final destination pathway where proteins + are · · modifies proteins packages proteins o the vesicles bud of from the Trans surface trans face releases proteins in Vesicles to go · lysosomes · membrane secreted/excreted out of cell Lysosomes · specialized vesicles derived from golgi that degrade damaged/unneeded macromolecules containhyavoutic enzymes that breakdown Diomolecules to recycle old organelles/material that has been brought into a cell ex a bacterium : · proteases breakdown proteins - · lipases-breakdown lipids nucleases breakdown nucleic acids aucosidases breakdown carbs - peroxisomes Neutralize free radicals Catalase , Oxidace (Gree radicals 02 :202 OD-bad) -. Metabolic enzymes Break down acids (oxidation) o then make a type of lipid cholesterol fatty Mitochondria Derobic respiration (uses oxygen) to Synthesize ATP outer membrane wh high permeability inner membrane-cristae low permeability · , ATP synthesis occurs via ETc - oxidative phosph Ribosomes protein synthesis location translation · - · a components large subunit (60s) = small subunit - (40s) rRNA6 protein Plant Cell Only Structures > chemical Chloroplast pathways photosynthesis convert sunlight energy - of energy by synthesizing carbs - · Thylakoid Membrane- highly folded zra internal membrane & center of chloroplast I · light reflecting pigments o is site of photosynthetic ETC contains · stroma-provides volume around structures within chloroplast for protection where light independent reaction of photosynthesis ala carbocycle happens · - - · cell Wall Central vacuole - hold materials Wastes also maintain proper pressure within , a plant cell tugor pressure ·