Cells, Tissues, and Organs
Cells, Tissues, and Organs LIFESCI 2
Popular in Course
Popular in Life Sciences
This 9 page Class Notes was uploaded by Nellie Botsford on Friday September 4, 2015. The Class Notes belongs to LIFESCI 2 at University of California - Los Angeles taught by R. Cooper in Fall. Since its upload, it has received 122 views. For similar materials see /class/177798/lifesci-2-university-of-california-los-angeles in Life Sciences at University of California - Los Angeles.
Reviews for Cells, Tissues, and Organs
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/04/15
L8 2 Midterm 1 Study Guide Lecture 1 Biological Molecules Chemical Bonds Water Math Lipids Covalent strong sharing e39 Noncovalent weak alelonic ie NaCl polarnonpolar very strong Hydrogen H interaction with NOF Hydrophobic interactions fatty acids nonpolar groups Van der Waals forces slight positivenegative charges interacting High specific heat gt homeostasis Adhesive properties good lubricant High surface tension Cohesion Good solvent nutrients chem rxns oxygen and carbon dioxide Solid form is less dense than liquid more stable HH bonding High heat of vaporization sweating helps cooling pH 7 1 mole 602x1022 molecules pH logH aleLow pH acidic release H generally organic acids are weak and inorganic are strong High pH basic release OH39 or take up H Prostaglandins derivatives of fatty acids which act similar to hormones Doubetriple bond gt doesn t allow rotation unsaturated All single bonds gt allows rotation saturated Fats triglycerides source of energy protect and insulate consist of glycerol and fatty acid Lipid triglyceride Polar head hydrophilic aleNonpolar tails hydrophobic Phospholipid glycerol backbone 30 with 2 fatty acids and 2 carbons attached to the phosphate group attached to the polar head l Amphipathic 2 ends polarnonpolar aleLipid bilayer cell membraneplasma membrane Movement gtRotate gtDiffuse gtTail dance gtFlipflop rare aided by flipases proteins that allow phospholipids to flipflop Adipocytes fat cells Prostaglandins derivatives of fatty acids which act similar to hormones Glycerol palmitic acid gt 3 H20 triglyceride Steroid steroid hormones are derived from cholesterol Cholesterol 4 ring structure aleFound in plasma membrane of animal cells and intercalates into bilayer slows movement of phospholipids and stabilizes membrane via Van der Waals interactions Atherosclerosis high levels that deposit on artery walls causing heart attacksstrokes gtLDLs carry cholesterol to tissue gtHDLs carry cholesterol to liver for excretion Level of blood cholesterol should be under 200 mgdL HYDROPHILIC O WOI39DO UltI gtHDL level less than 35 mgdL increases your risk for heart disease higher your HDL level the better LDLCholesterol Categories Less than 130 mgdL Desirable 130159 mgdL Borderline high risk 160 mgdL and above High risk Carbohydrates sugars and starches ie Glucose and glycogen Rati0121 CHO Provide energy glycogen stored as glucose in liver and skeletal muscles Form part of structural elements of some cells Supply carbon atoms for synthesis of cellular components Monosaccharides simple sugars glucose Disaccharidres covalently bonded monosaccharides lactose lactose intolerance lactase deficient and maltose Polysaccharides more than 2 monosaccharides glycogenanimals branched liver and skeletal muscle and starch plants cellulose broken down by hydrolysis Proteins Amnio acids Type Nameimportance 3Letter Abbreviation 1Letter Abbreviation Positive Hydrophilic Arginine Arg R Histidine His H Lysine Lys K Negative Hydrophilic Aspartic Acid Asp D Glutamic Acid Glu E Uncharged Hydrophilic Serine Ser S Threonine Thr T Asparagine Asn N Glutamine Gln Q Tyrosine Tyr Y Special Cysteine 2SH gtH20 SS form Cys C disul de bridges in tertiary structure Glycine R group is only H Gly G smallest R Proline planar wo rotation Pro P because of cyclopentane bw R and N Nonpolar Hydrophobic Alanine Ala A lsoleucine lie I Leucine Leu L Methionine Met M Phenylalanine Phe F Tryptophan Trp W Valine Val V H and OH groups bond to release water and join AAs Structure Amino Acid Structure alePrimary Structure chain of Ms wpeptide bonds l Secondary Structure alpha helices and beta pleated sheets by hydrogen bonds local 171 interactions bw AA residues H N C C OH l Tertiary Structure 3D shape of protein caused by groups brought together via secondary A6333 Cm g dd structure includes sulfide bonds sidecmm l Quaternary Structure subunits fitting together to form structure Only L isomers are biologically functional Serve as enzymes l Proteases break proteins l Lipases break lipids Dehydrogenases remove H RBCs Oxyhemoglobin Sickle cell disease genetic mutation that switch Glu polar to Val in presence of low 02 it sticks out and forms long chains of hemoglobin capillaries clog up painful pH 735745 Model membrane gtNo nucleus gtEasy to get gtFew organelles gtPut in water gtburst gtcentrifuge gtpure membrane DNA Purines l Guanine Adenine Pyrimidines Cytosine l Thymine uracil Complementary base pairing A TU GC Double helix structure gtstability gtstrength in number of hydrogen bonds Semiconservative replication I Tangggarrnou WW RNA II quotIn quot 1 39RNA 39W 3 0 lt1 9 mRNA messenger takes Info from DNAto rIbosomes transcription 5 EIII if 0 rRNA ribosomal translation site codon on rRNA 5 3235 imm 399 O I I I I Elan tRNA transfer 20 dIff for 20 Ms genetIc code trIplet 3 bases 1 AA anti gmuimggm I 3mm U o codon on tRNA ttnl 32fllmu u v WW 0 39 I monilioatontoauw 399 39 I 0 Cl nmlnoacyHFmA synlnu39luso Lecture 2 Cell Structure Characteristics of Prokaryotes and Eukaryotes Biosphere gtcommunity gtpopulation gtorganism gtorgan gt WWW sq m 39 a 0 mRNA leaves the tIssueI gtcell gtmolecule gtatom 33333333411 mun I II Mummmw Termnoogy warml 1 E 23 53 im l Molecule cluster of atoms held together by chemical bonds RNA wumnonnlpor Organelle structure wi a cell that performs a specific function 0 speci c enzyme I I n Cell simplest entity that has all the properties of life a membranebound unit 7 containing DNA and cytoplasm Rimm Q 3 Tnmsunou quot 39 quotT I f I lI 9 3 succession of nuns I I I I subunits 7 it TIssuIe a groups of Similar cells that carry out a particular functIon In an I Ix ogfI Irgmggg 39ns organIsm gig Am mm 39quot Epithelial lines digestive tract and covers openings to outside l Muscle contractile proteins Nervous tissue action potential delivers signals l Connective tissue ie Bone has calcified matrix ie blood has liquid matrix plasma Organ structures composed of more than 1 tissue type Organ system related organs performing a common function Organism individual indecent living entity 31 cod 1 Museum Hibosnmc 6 Life s Key characteristics V 43 fTr3 Cellular organization all organisms consist of 1 or more cells Light vs Electron microscopes Sensitivity organisms respond to various stimuli in different ways Excreted waste 002 Growth organisms interconvert chemical molecules metabolism Taken in 02 and glucose and energy released is used to grow Cell Survival Reproduction organisms reproduce passing on traits to new Obtaining and processing energy generations Converting the genetic info of DNA to protein Homeostasis organisms maintain relatively constant internal Allowing biochem rxns to occur conditions ie pH different from their environment Prokaryotes Cell Theory Lack nucleus DNA coiled into nucleoid region All organisms are composed of cells Plasma membrane The cell is the basic building block of life chem rxns of life take Cytoplasm ribosomes place wi cell Cell wall peptidoglycan in bacteria All cells arise by division of preexisting cell Outer membrane outside wall Cell Size Capsule outside outer membrane Most cells can t been seen with naked eye Flagella to swim 45 nm in diameter rotate Small size keeps high SAV ratio to keep rate of metabolism Cyanobacteria carry out photosynthesis can have volume faster than rate of intakewaste removal SA chlorophyll SA 4rrr2 Circular chromosome No cytoskeleton molecular motors Peroxisomes Pili involved in mating project from surface of some bacteria 39Nucleus exchange of DNA primitive mating Nucleolus assembles ribosomes V Eubacteria cyanobacteria and archaebacteria DNA replication Eukaryotes Protein production control Large membrane bound nucleus Largest organelle most of cell s Highly compartmentalized into organelles wspecial fxns DNA 5 microns in diameter Plasma membrane Filled with nucleoplasm Cytoplasm Enclosed by nuclear envelope 2 Ribosomes membranes perforated by nuclear Cilia made from actin back and forth motion pores nterna cytoskeleton maintain cell shapemove materials DNA combined wprotein to form chromatin Plant cell has giant vacuole and cell wall cellulose When nucleus is going to divide chromatin condenses and Plantanimal cells coils to form chromosomes Larger than prokaryotes Contains nucleolus site of ribosomes assembly Thought to have arisen from prokaryotes by endosymbiosis Nucleoplasm fluid material wi nuclear envelope Endosymbiosis Nuclear lamina is a network of proteins lamins that Mitochondria maintain nucleus shape l Plastids Humans have 36 pairs of chromosomes Lysosomes Ribosomes Made of rRNA and proteins 50 All cells synthesize proteins on ribosomes n eukaryotes Free in cytoplasm Attached to rough ER akin energy producing organelles mitochondrial matrix chloroplast stroma Ribosomes consist of a type of RNA together with protein comprising of a large and small subunit which associate during protein synthesis COOH head and NH2 tail of AA chain mm Role of signal sequences in directing proteins to various organelles specific hydrophobic sequence of approx 25 AAs at the beginning of a polypeptide chain directs it into the ER bound to signal recognition particle gtbinds to site on ER I I I AUUAUGGCEUGGAEUUGAAAGC Senes of Interrelated membranes and compartments In eukaryotrc cells 1 Filled with lumen Endoplasm reticulum kExtensive folded membranes forming sacs and tubes l Cells which synthesize proteins for export contain large amounts of ER liver glands Smooth ER no attached ribosomes site of glycogen hydrolysis steroid synthesis Rough ER attached ribosomes manufactures proteins for export from cells incorporation into membranes of moved into organelles of the endomembrayne system site for addition of short sugar chains to proteins glycoproteins end in vesicles that go to the Golgi Golgi Apparatus Series of flattened membranous sacs cis face is closer to nucleus and trans face is closer to cell surface Modifies packages and sorts proteins and adds complex sugars Synthesizes some polysaccharides for the cell wall Vesicles from the rough ER fuse with the cis region of the Golgi body and secretory vesicles are pinched off from trans face mm mm nuunuootcuooncuuonnnoc 39Mitochondria Powerhouse Converts energy from food into ATP adenosine triphosphate energy currency of cell Small similar size to bacteria nnerouter membranes inner is highly folded forming finger like projections called christae Mitochondrial matrix contains ribosomes and DNA Almost all eukaryotes contain mitochondria expt those living in places wo 02 More mitochondria and present if they are very active ie Heart muscle PyruvategtATP Cellular respiration Absent in anaerobic eukaryotes Plastids Present in plants and some protists Serves for food manufacturestorage ie Chloroplasts and photosynthesis 2 membranes both unfolded Stromd Thylakoid Gran um inner quotquot membrane Outerquotf membrane lnnermembrane forms flattened sacs called thylakoids stacks of thylakoids grana Chlorophyll in thylakoid membrane Stroma wi inner membrane contains suspended grana ribosomes and DNA Endosymbiotic theory and the origin of mitochondria and chloroplasts may have originated when larger prokaryotes engulfed smaller prokaryotes Organelles involved in Breakdown and storage Lysosomes Contain hydrolytic digestive enzymes participate in phagocytosis acidic pH 55 TaySachs inherited can t break down gangliosides lacking enzyme gtlipids build up in nervous tissue and brain newly formed vesicle Golgi phagosome Peroxisomes plantsanimals combine with oxygen to form peroxide Glyoxysomes plants Vacuoles present in plant cells store waste products and provide turgor Organelles involved in support and movement Cytoskeleton maintains cell shape facilitates cell movement and certain fibers act as tracks for motor proteins Cells wall present in plants fungi and some protists also in bacteria Extracellular matrix surrounds animal cells composed of proteins ie Collagen glycoproteins and proteoglycan Cytoskeleton Microfilaments strands of actin movement during animal cell division and muscle Endoplamic reticulum r 4 A a W4 m quotv 45 7 45 t apparatus t iquot if umquot it i l w39 Exocy195ls 5 f D a v 71 9 i u P tbx t39 tel quotquot Iquot 391 r Prrnarv quot My quot cecmdrw t v w w Pvdedsor 1e ysosomes quot l isoeomes X Eddocytosis quotI c t t a quot it gtv 131 c rifftl gUlllt39 ar xy Erit lOSOr C Exocytosi dCS d uill 1 Miles 1 l yscsctmal engine3 O lalr tctegratlodresidual ll ZlZO39lLr Extracellular ntazeria J Bacteria Nature Reviews Genetics contraction make villi erect and connect to intermediate filaments that make up base polarity muscle contraction reorganization after cell division ntermediate filaments tough fibrous protein molecules twisted into ropelike structures stabilizing cell shape nonpolarized nuclear lamina matrix in the cell for tethering hold organelles in place desmosomes Microtubules hollow cylinders made of tubulin involved in structure and fxn of cilia and flagella centrioles and movement of cellular organelles Motor proteins ie Dynein and kinesin use energy from ATP to change their shape and move things attached to microtubules Plant and Animal Cell Differences Centrioles absent in plant cells Vacuoles absentsmall in animal cells Cell wall absent in animal cells extracellular matrix may be present Chloroplasts absent in animal cells Some animal cells have flagella absent in plants except sperm in a few species Cilia 92 structure of microtubules that turns into triplets near base Dynein motors join proteins of microtubules Lecture 3 Structure and Function of Cell Membranes All cells are bound by plasma membrane Provides a permeability barrier to transport certain molecules Membrane plays key role in response of cells to external stimuli oMembranes involved in energy transduction Composition of Membranes Lipids physical integrity kPhospholipids are main structural components Spontaneously form bilayer sheets where hydrophobic tails point inward kUnsaturated lipid tail has kink l Fluid Depends on composition and temperature gtAs temp falls the bilayer changes from fluid to rigid gel state phase transition at a characteristic temperature gtTemp at which this occurs is lower harder to freeze less Van der Waals interactions if Rou git endoplasm ic reticulum Intermediate A y filament if r l l 1 I t L I Iquot39YE 97Bm t39 I t r 39 391 T t y lr w 1 2 m J 39l i A g L 39 Actin monomer jigv Fibrous V subunit dimer monomer monomer Direction of movement if i eEnd r r 277 I7 Kinesin Vesicle or organelle Microt ubule r7quot of cytoskeleton Ankyrin Actin Tropomyosin Band 41 Spectrin 0 Band 3 xGchophorin A Proteins hydrocarbon chains are short or have double bonds eleCholesterol important to membrane in animal cells polar head close to polar head of phospholipid also contributes to lowering temperature l Nonpolar interior of bilayer prevents any watersoluble molecules passing through bilayer permeability to watersoluble molecules is achieved by the presence of specific protein molecules perform specific fxns ie Transport receptors l Carry our most specific fxns l Amount and types of proteins in a membrane varies 3 classes based on relationship to bilayer gtlntegral penetrate into bilayer most are transmembrane contain an alphahelix of nonpolarAvAs extending across the hydrophobic interior of membrane and amine group hanging on outside revealed from freezefracture method gtPeripheral proteins outside of bilayer on the cytoplasmic surface attached by H bonds to the polar head groups of the lipid bilayer or to integral membrane proteins bathe in salt to remove gtLipidanchored proteins covalently attached to a phospholipid or fatty acid embedded in the bilayer l Some cells have cytoskeletal protein network ie RBCs l Beneath the cytoplasmic surface of the RBS spectrin forms a mesh Spectrin attached to membrane junctional complexes by action and to ankyrin peripheral protein which in turn is attached to an anion channel integral protein ie Band 3 l Transport proteins Receptors for molecular messengers from other cells l Form junctions bw cells Carbohydrates serve as recognition sites on the cell surface l Project from exterior surface of plasma membrane when attached to proteinsphospholipids wi membrane l Serve as recognition sites on the cell surface l Most carbohydrates in membranes are bound to proteins forming glycoproteins bound carbohydrates are oligosaccharide 1014 monosaccharides chains enable cells to recognize foreign substances eleGlycolipids form cell identity markers ie A B 0 blood group markers l Glycoproteins attached to proteins most carbs in this form Fluid Mosaic Model Cell Adhesion l How proteins are incorporated into the bilayer l On outer surface carbohydrates are attached to proteins or phospholipids Plasma a A membranes 4 g gfanes a c Intercenuiar Homotypic binding same types of cells u rrgggge39m39w v I I I I I I g 39i 7 Ir 4 r 2255 39 39 H d hl T 3 iii539quot Heterotypic binding different types of cells ie Mating Cra2quot y x 39 39 39 quot M l I 2 quot i a gt i 39 Tlg JUnCtIOnS paOSSiJUetevieen fl quot 39 Adhesion 39 39 cc 39 u ttE Cells prote39ns a I Gives cell a Sidedness and polarizes the cell often found In ii A Ea Jncti g quot connexons Keratin fiber epithelial tissue pi Desmosomes intermediate filaments Gap junctions ntegrins mediate the attachment of animal cells to extracellular matrix on channel protein needed aqueous pore ions ie Na don t readily cross membranes so they use water filled pores created by intrinsic membrane proteins channels lon channels play Rate of diffusion elePermeability barrier gquot i 15 i391397r j2 5 rquot if N siw a 34 7 3 aSI I la 5 r x t 39 a memb anes r3 a g L913 J39 39 39 r quota v 3 t f 39 39 e w 1 J 1 l nte rcel l u ar space o o o 399 5 A nu v isquot f ff339 731 1 I 371 7 ifwvvi L 7733 I 3939 I A v 2 13quot Degu n S f 193 q 1 r p l Component in heart for action potential eleUses connexons 6 subunits Tight junctions 0 o 0 39a o c m Desmosomes l Movement of Molecules Across Cell Membranes Passive down concentration gradient Diffusion l Random molecular motion produces net migration of molecules toward regions of lower concentration l When molecules become uniformly distributed a state of equilibrium exists eleWi cells solutes distribute rapidly by diffusion due to short distances involved l Small nonpolar molecules can diffuse across the lipid bilayer l Molecules whigh lipid solubility diffuse more rapidly 602 and C02 can readily diffuse across membranes Osmosis diffusion of water molecules across selectively permeable membrane elelmportance of water balance bw cells and their surroundings compare behavior of mammalian RBCs wcells wwalls l Straight line graph of amount by rate of diffusion Gap junctions Outside of cell Outside of cell Extracellular matrix Inside of cell quotquot quot a c 0 Eggs isotonic Hypotonic H30 Hyperionic H20 tn 11ll l talCL H gt h Plant cell an essential role in signaling by the nervous system may be ligand or voltage gated water has its own pore aquaporin Carrier transporter molecules ie Glucose bind to carrier proteins in the membrane and are transported across particular carrier transports only certain gt molecules may become saturated if all carriers are in use Amount of glucose Active transport across membrane by a carriermediated process against the concentration gradient req chemical energy Types of channels Endocytosis Lecture 4 Introduction to Enzvmes and Energetics Carrier transporter ie NaK pump alePrimary active transport req direct participation of ATP NaK l Secondary active transport doesn t require ATP directly but rather the energy in 0 an ion gradient set by primary active transport glucose while other is pumped a down concentration gradient ie Na Outside of cell Sodium potassium pump Uniport single direction single molecule Symport single direction 2 molecules Antiport 2 directions 2 directions Transports macromolecules large particles and small cells into eukaryotic cells Plasma membrane envelops materials and forms a vesicle inside the cell 3types Extracellular uid with high concentration of Na Phagocytosis large particles or cells are engulfed l Pinocytosis small dissolved solutes or fluids enter aleReceptormediated endocytosis a specific membrane receptor binds to a particular macromolecule at sites called clathrin coated pits ie Uptake of cholesterol in association wLDL Materials in vesicles are secreted from the cell when vesicles fuse wthe plasma membrane The sodium potassium pump Sodium ions Na are pumped out of the cell and potassium ions K are pumped into the cell The energy to drive the pump is released by hydrolysrs of ATP intracellular fluid with low concentration of Na and high concentration of K Energy the capacity to do work Energy flows into the biological world from the sun stored as potential energy in the chemical bonds of sugar molecules formed by photosynthesis Energy cannot be created or destroyed 1St Law of Thermo Outside of cell KE workassociated W o 9 P o W Glucose I O Sodium potassium pgnp y I t o o L 39 quotI ab v t l r 1 cl Ir if ll 3 ll l i 1 1 ii t l l i 39l 5 11 ll quot7 a l l V During any energy interconversion some energy is released as heat adding to entropy w I J o J Insideof ce Increasing disorder of the system 2nOI Law of Thermo Ie Muscle contraction 9 o 93 o 0 Q 0 APP are 5 0 o a Life converts energy from the sun to other forms to sustain life energy never lost but as it is utilized more and more is converted to heat Chemical rxns sustain life Metabolism sum of all chemical processes occurring wi a cell or organism Metabolic pathway rxns often occur in series product of one rxn becomes a reactant in the 5W 3 WW WW next rxn WOMDHSM Lquota on bdo oh Sun Chem rxns est equilibrium and the equilibrium constant Keq is the ratio of the concentration 3 305 of products and reactants at equilibrium MR r P V 7 A high Keq indicates that the rxn goes far toward completion C 07 nLo an a3 t Breaking of chemical bonds in the course of chem rxns produces changes in Gibbs free energy ex Of metabolism Ii d Free Energy Entropy and Enthalpy Change in free energy AG of any rxn is characterized by the change in enthalpy AH and the change in entropy AS Gibbs Free energy equation AG AH TAS Chem rxns and energy Rxn whose products contain less free energy than the reactants negative AG will occur spontaneously and release heat exergonic In an endergonic rxn the products of the rxn contain more energy than the reactants and the extra energy must be supplied for the rxn to occur positive AG Rxn that goes to almost completion has a large negative AG AG value near zero is characteristic of a readily reversible rxn AG gives no info about rxn rate Adenosine Triphosphate ATP Serves as the energy currency of the cell ATquot ATP Removal of one phosphate yields 7 kcalmol Adenine VH2 ATP hydrolysis releases large amounts of energy RCN Synthesis of ATP from ADP and Pi req energy HJR jawH ATP couples exergonic and endergonic rxns phospmgmps N fireflies use ATP to generate light bioluminescence coupled wNa pump Ofjo of om O ATP gtADP AMP gtadenosine lt5 c39r z Ft PPP energy covalent bonds 5 OH OH A Synthesis of ATP requires energy Cells can make ATP 2 ways l substratelevel phosphorylation Chemiosmosis majority made this way inner mitochondrial membrane requires 02 Ribose lt Adonosino gt lt AMPAclennsinc monophosplmtc gt lt ADP Adenosine dipliosphate gt o Adenosine triphosphate gt Activation Energy Before a rxn can proceed even for spontaneous rxns energy must be supplied to break existing chem bonds Activation energy energy req to destabilize existing chem bonds and start a chem rxn Rxns wlarger activation energy tens to occur more slowly Catalysts reduce activation energy and increase the rates of rxns but don t affect final equilibrium Enzymes Enzymes are proteins which carry out most of the catalysis in cells some catalysis is carried out in RNA ribosomes Enzymes speed up rxns by lowering the energy barrier bw reactants and products increase rate but not AG Substrate molecules bind at the active site Enzymes have optimum pH and temp at which they fxn most effectively Some enzymes require coenzymes to fxn ie NAD some enzymes change shape when substrates bind to them May couple exergonic and endergonic rxns to catalyze otherwise unfavorable rxns Activity of enzymes is regulated in various ways decreased by competitive and noncompetitive inhibitors allowing for precise metabolic control Allosteric enzymes exhibit sigmoidal kinetics when rxn rate is A Competitive inhibition Competitive W inhibitor 0 Active site j Git lt93 B Noncompetitive inhibition Substrate o 0 Active site 4 awe4V Noncompetitive inhibitor Substrate Inactive form Active form Catalytic subunit Active site I I I A plotted against substrate conc and are Important srtes of T metabolic control Inhibitor N Ac vator I are 35355ng site Proteases break down proteins Lipases break down lipids Substrate Experiment some enzyme is several test tubes with increasing a substrate at a fixed time to measure product Allosteric Allosteric 39 I n h b rs inhibitor I activaItor gtCompetitive tries to go to active site gtNoncompetitive different site changes the active site s shape lrreversible Product formation No product formation Endergonic reaction 0 Active transport 0 Cell movements 0 Anabolism Exergonic reaction 0 Cell respiration 0 Catabolism Pi I Ra t9 of reaction Reaction without 2112 me 3 Acetylcholinesterase I p Active gt Site If i I 5 DlPF 7 u I 7 I A lt gt I Covalent attachment of DlPF DIPF an irreversible inhibitor reacts with the hydroxyl group of serine The hydroxyl group is on the side chain of serine in the active site to the active site prevents substrate from entering V V CH3 CH3 HCH3 HCH3 o 0 Ser on F P Ser 0 P Active site O O senne 446 ll Allostcric multiple subunit enzyme a Singlesubunit enzyme gtDPF to acetylcholinesterase wcovalent bonds and stops substrate from entering Rates Allosteric effects rate to allow for regulation early in enzymatic chain Lecture 5 Glycolysis and Cellular Respiration Chem energy to drive metabolism Autotrophs use light energy to synthesize food molecules Heterotrophs and autotrophs extract energy from food Extraction of energy from food occurs in stages Enzymes break large molecules into smaller ones digestion Other enzymes dismantle fragments extracting energy at each stage overall process called catabolism Glucose C6H1206 CH bonds progressively harvested for energy using electrons making up the bond to generate ATP Glycolysis Conversion of glucose to pyruvate Followed by cellular respiration C6H1206 602 gt 6002 6H20 ATP ATP synthesis In W cm Substratelevel phosphorylation O I cm 5 I Hz lnvolves direct transfer of phosphate group to ADP from another migjj gggml 39 3 mg Ci O o Phosphoenolpyruvate mOIGCUIe i0 memes gti ie Phosphoenolpyruvate PEP contains high energy phosphate 2 COI I Pyruvate 2 molecules Reaction rate L gt r r Concentration of substrate Stage I ll Fatty nerd and Glucose and Ammo acrds l glycerol other ugars X 39 i Stage I ll Acetyl CoA FATS POLYSACCHAHIDES PROTEINS I Jl le bond similar to ATP which can be enzymatically transferred to ADP ChemiosmosisOxidative Phosphorylation Cytoplasm J3 l ATP formation in the mitochondrion resulting from flow of Weummiuubmhuuwwmpuppy w electrons through respiratory chain mietgmgriai W l NADH molecules transfer electrons to a series of membrane muwwumwmwu J unnuwum 39 39ntem embrane ELECTRON TRANSPORT ATP SYNTHESIS protein complexes NADH Q reductase cytochrome reductase and space w A w V Aw I 39 39 l 9 H in w w in cytochrome OXIdase the respiratory chain electron transport NADHQ Ubiqw 3er Cytochro ec Cytochrome chain ETC oxidase l ln conjunction wETC protons are pumped across the membrane from the matrix l Energy of this proton gradient protonmotive force across the inner mitochondrial membrane is used to drive ATP synthesis chemiosmosis l Return of protons to the matrix is coupled to synthesis of ATP via an ATP synthesis l Experiments gtln the absence of ETC an artificial H gradient is sufficient forATP 0 synthesis by mitochondria ATP synthesis acting as an H channel is necessary forATP synthesis reductase Matrix of mitochondrion Redox Rxns Reduction gain of one or more electrons by an atom ion or molecule Oxidation loss of one or more electrons Transfer of electrons is an oxidationreduction redox reaction Oxidation and reduction always occur together In a redox rxn the reactant that becomes oxidized is a reducing agent Coenzyme NAD is an electron carrier in many redox rxns l NAD serves as an electron shuttle l Exists in 2 forms 50 gtOxidized NAD gtReduced NADH H Functions as a coenzyme wdehydrogenases specific type of Cytochrome c u z 0 reductase N ADHQ quot complex 20 reductase Cytochrome c complex 30 Change in free energy relative to 02 kcalmol enzyme Oxidized form NAD Reduced form r 3 Energy is harvested from glucose molecules in gradual steps using I 12 illof W L GIYCOIYSISOxidizes glucose to pyretic acid anaerobic W Occurs in 10 separate enzymatic rxns in cytoplasm quot ti on Net gain of 2 ATPs approx 5 of energy available to call from glucose w Stages of cellular respiration following glycolysis release much more energy l x Krebs Cycle Ilt Aka citric acidtriboxylic acid cycle Pyruvate enters mitochondria and is oxidized forming acetyl coenzyme A 0 Acetyl 00A 20 combines woxaloacetate 40 to form citric acid triboxylic acid and CoA Results in complete oxidation of acetyl units to C02 Oxidation of NADH theoretically yields 3 ATPs in practice 25 ATPs per NADH FADH2 yields 15 ATPs Cellular respiration yields much more energy than glycolysis net yield approx 32 ATP molecules glucose Hydrogen Release of hydrogen atoms occur during specific rxns of the cycle hydrogen acceptors carriers are NAD and FAD Q X The reduced carriers NADH and FADH2 are energy rich molecules because each ruffmm Go Col contains a pair of electrons that have a high transfer potential WWW W Transfer of these electrons to molecular oxygen releases a large amount of energy which WW W can be used to generate ATP
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'