Attributes of Life Attributes of Life 16 and 21 November 16 and 21 November Introduction to life Introduction to life Themes/characteristics of Themes/characteristics of living organisms living organisms Structural and functional Structural and functional characters characters
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Attributes of Life 16 and 21 November Introduction to life Introduction to life Themes/characteristics of living organisms Themes/characteristics of living.
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Attributes of LifeAttributes of Life16 and 21 November16 and 21 November
Introduction to lifeIntroduction to life Themes/characteristics of living Themes/characteristics of living
organismsorganisms Structural and functional Structural and functional
characterscharacters
IntroductionIntroduction
What defines life?What defines life? ________________________________ ________________________________ ________________________________
ThemesThemes
Hierarchy theory and emergent propertiesHierarchy theory and emergent properties Structure: “it is the cell”Structure: “it is the cell” Continuity of life: function of “information”Continuity of life: function of “information” Openness of biological systemsOpenness of biological systems Regulatory capacity of living systemsRegulatory capacity of living systems Capacity to reproduceCapacity to reproduce Capacity to acquire, utilize, and store energyCapacity to acquire, utilize, and store energy Diversity and similarity of living systemsDiversity and similarity of living systems
Hierarchical Nature of Hierarchical Nature of Living SystemsLiving Systems
CommunityCommunity PopulationPopulation
OrganismOrganism OrganOrgan TissueTissue
CellCell OrganellesOrganelles
MacromoleculesMacromolecules
AtomsAtoms
InfrastructureInfrastructure
Cell: Structure and Cell: Structure and FunctionFunction
Organism’s basic unit of structure and Organism’s basic unit of structure and functionfunction Lowest level of structure capable of Lowest level of structure capable of
Most common basic structure of all living Most common basic structure of all living organisms organisms
Cell TheoryCell Theory Ubiquitous nature of cellsUbiquitous nature of cells All cells come from previous cellsAll cells come from previous cells
General Cell StructuresGeneral Cell Structures
Continuity of Life and Continuity of Life and InformationInformation
Order in any system originates from Order in any system originates from instructions serving as a template for instructions serving as a template for organization (e.g., Constitution, Bill of organization (e.g., Constitution, Bill of Rights)Rights)
In living systems, instructions codified In living systems, instructions codified in the DNAin the DNA
Instructions/inheritance based on the Instructions/inheritance based on the precise, sequential order of precise, sequential order of nucleotides (ATCG)nucleotides (ATCG) Example: RAT versus TAR versus ARTExample: RAT versus TAR versus ART
Open SystemsOpen Systems
All living organisms are open systems, living organisms are open systems, allowing organisms to interact with allowing organisms to interact with their environmenttheir environment Processing stimuliProcessing stimuli Responding to stimuliResponding to stimuli
““Open” versus a “closed” systemOpen” versus a “closed” system ExamplesExamples
Orientation of leaves to sunOrientation of leaves to sun EyesEyes Microbes and single cell organisms (e.g., Microbes and single cell organisms (e.g.,
amoeba)amoeba)
Examples of Open Systems
26-580Figure 26.41
Eye
Sun-Tracking Plants
Regulatory SystemsRegulatory Systems
Interplay of organisms with the Interplay of organisms with the environment requires a well balanced environment requires a well balanced regulatory systemregulatory system
Outcome: Outcome: homeostasishomeostasis Set point, effectors, control centers and Set point, effectors, control centers and
sensorssensors Analogy: thermostat for heat controlAnalogy: thermostat for heat control ExamplesExamples
Enzymes in cells (lab exercise this week)Enzymes in cells (lab exercise this week) Thermostatic control of body temperatureThermostatic control of body temperature pH of the cellpH of the cell
Feedbacks (+ and -), homeostasis and Feedbacks (+ and -), homeostasis and cyberneticscybernetics
Control Center/Sensor
Set Point Effector
PositiveFeedback
NegativeFeedback
Universality of Universality of ReproductionReproduction
Reproduction: regenerative Reproduction: regenerative process of making new process of making new organisms (not necessarily organisms (not necessarily copies)copies)
MethodsMethods Sexual Sexual Asexual (microbes; cell Asexual (microbes; cell
division/mitosis)division/mitosis) Ancillary but important Ancillary but important
function: creating new variantsfunction: creating new variants ExamplesExamples
SiblingsSiblings Geranium plantsGeranium plants Dolly (the sheep)Dolly (the sheep)
Energy UtilizationEnergy Utilization
Three related activities: acquisition, Three related activities: acquisition, utilization, and storageutilization, and storage
Energy AcquisitionEnergy Acquisition Energy capture (autotrophs; heterotrophs)Energy capture (autotrophs; heterotrophs)
Energy utilizationEnergy utilization Laws of Thermodynamics (1Laws of Thermodynamics (1stst and 2 and 2ndnd laws) laws) ATPATP (adenosine triphosphate) and (adenosine triphosphate) and ADPADP
(adenosine diphosphate(adenosine diphosphate Energy storageEnergy storage
Chemical bonds (C-C covalent bonds)Chemical bonds (C-C covalent bonds) Starch, glycogen and lipidsStarch, glycogen and lipids
Energy UtilizationEnergy Utilization
Catabolism Biosynthesis/Anabolism
ADP
ATP
Two Sides of a Coin: Two Sides of a Coin: Diversity and SimilarityDiversity and Similarity
DiversityDiversity is a hallmark of living systems is a hallmark of living systems 1.5 M known species of plants, animals and 1.5 M known species of plants, animals and
microbesmicrobes 100 M+ thought to exist100 M+ thought to exist
SimilaritySimilarity is a hallmark of living systems is a hallmark of living systems Striking similarity at the molecular level (DNA): Striking similarity at the molecular level (DNA):
kinship to worms, squirrels, birds and pigs (you kinship to worms, squirrels, birds and pigs (you DNA is ~90% pig)DNA is ~90% pig)
ExamplesExamples BiochemistryBiochemistry Structure and morphologyStructure and morphology DNADNA
DNA phylogeny lab (December)DNA phylogeny lab (December)
What is Life? “Nuts and What is Life? “Nuts and Bolts”Bolts”
Introduction to lifeIntroduction to life Themes/characteristics of all Themes/characteristics of all
living organismsliving organisms Cardinal structural and Cardinal structural and
functional charactersfunctional characters
Structural and Functional Structural and Functional CharactersCharacters
Cells as the physical infrastructureCells as the physical infrastructure Biological catalysis: enzymesBiological catalysis: enzymes Cell membranesCell membranes Water as the medium of lifeWater as the medium of life Polymers (C-based polymers)Polymers (C-based polymers) Compartmentation Compartmentation viavia organelles organelles Major types of cellsMajor types of cells
Cells as the Physical Cells as the Physical InfrastructureInfrastructure
Cell theoryCell theory All organisms composed of cellsAll organisms composed of cells Cells as smallest unit of organization exhibiting Cells as smallest unit of organization exhibiting
characteristics of lifecharacteristics of life StructureStructure
Cell Membrane
Nucleus
Cytoplasm
General Features of a General Features of a CellCell
Size correlated with functionSize correlated with function Upper limit: 0.00001 m (1 x 10Upper limit: 0.00001 m (1 x 10-5-5 m) m) Relationship of volume to distanceRelationship of volume to distance Anything over 1 x 10Anything over 1 x 10-5-5 m is nonfunctional m is nonfunctional
Efficacy of transport/diffusionEfficacy of transport/diffusion
Diffusion
23-479Figure 23.5
1 . 10-5 m
EnzymesEnzymes
IntroductionIntroduction Reactions are very slow (not sufficient Reactions are very slow (not sufficient
to sustain life)to sustain life) Mechanisms to accelerate specific Mechanisms to accelerate specific
Proteins (relate to information brokers)Proteins (relate to information brokers) Change rate of reactionsChange rate of reactions High degree of specificityHigh degree of specificity RegeneratedRegenerated
Energy Needed
ReactantsProducts
“Hill”
Base case for Base case for reactions to occurreactions to occur Reactants Reactants Products Products
Energy analysis Energy analysis (thermodynamics)(thermodynamics) Energy to cause Energy to cause
reaction to occur reaction to occur (over the “hill”)(over the “hill”)
Enzymes: How They Enzymes: How They WorkWork
How Enzymes WorkHow Enzymes Work Efficacy of enzymes: “Hill” Efficacy of enzymes: “Hill”
heightheight MechanismMechanism
Lower the height of the “hill”Lower the height of the “hill” Selectivity/specificitySelectivity/specificity
Protein 3-D structure (1, 2, 3, Protein 3-D structure (1, 2, 3, and 4 protein conformation)and 4 protein conformation)
ConclusionConclusion Absence of enzyme: minutes to Absence of enzyme: minutes to
hours to days to yearshours to days to years Presence of enzyme: 1,000 - Presence of enzyme: 1,000 -
10,000 reactions 10,000 reactions per secondper second Increase in rate > 10Increase in rate > 1066 orders of orders of
with principal monomer (lipid) with principal monomer (lipid) being a fatty acid + glycerol being a fatty acid + glycerol (i.e., phospholipids)(i.e., phospholipids)
Lipid bilayer at the molecular Lipid bilayer at the molecular levellevel
Phosphate/ Glycerol (Hydrophilic)
Fatty Acid (Hydrophobic)
Membranes: StructureMembranes: Structure
Lipid bilayer: “fluid membrane” with Lipid bilayer: “fluid membrane” with floating chunks of proteins and floating chunks of proteins and carbohydrates (i.e., icebergs)carbohydrates (i.e., icebergs)
Lipid Bilayer
Protein Chunk
Proteins in Lipid BilayerProteins in Lipid Bilayer
Membranes: FunctionsMembranes: Functions
Example of hierarchy theory and Example of hierarchy theory and emergent propertiesemergent properties
Selective permeabilitySelective permeability Signaling: cell-to-cell communicationSignaling: cell-to-cell communication
Transport through Transport through Membrane: Selective Membrane: Selective
Water: Medium for Water: Medium for MetabolismMetabolism
Liquid medium for metabolism and its Liquid medium for metabolism and its importanceimportance
Role of water (HRole of water (H22O)O) Physical properties (e.g., polarity, phases)Physical properties (e.g., polarity, phases) Chemical properties (e.g., pH, solution)Chemical properties (e.g., pH, solution)
Exquisite and unique properties of HExquisite and unique properties of H22OO
Define polymer…..Define polymer….. Major biomacromolecules of carbonMajor biomacromolecules of carbon
Carbohydrates (monomer is ______)Carbohydrates (monomer is ______) Lipids (monomer is _______ + _______)Lipids (monomer is _______ + _______) Proteins (monomer is ____________)Proteins (monomer is ____________) Nucleic acids (monomer is __________)Nucleic acids (monomer is __________)
““Information brokers”, particularly for Information brokers”, particularly for nucleic acidsnucleic acids Analogy to an alphabetAnalogy to an alphabet
General Cell StructuresGeneral Cell Structures
Principle of Principle of CompartmentationCompartmentation
Cells are compartmentalizedCells are compartmentalized Elaborate and organized infrastructureElaborate and organized infrastructure Analogy to a dormAnalogy to a dorm
Corridors as endoplasmic reticulumCorridors as endoplasmic reticulum Rooms as organellesRooms as organelles
Consequence of not being Consequence of not being compartmentalizedcompartmentalized
Compartmentation
23-494Figure 23.22
Cell TypesCell Types ProkaryotesProkaryotes
No typical nucleusNo typical nucleus No mitochondria, chloroplasts, No mitochondria, chloroplasts,
Golgi, or endoplasmic reticulumGolgi, or endoplasmic reticulum DNA, enzymes, metabolize, etc.DNA, enzymes, metabolize, etc. Example: bacteriaExample: bacteria
EukaryotesEukaryotes True nucleus and all the True nucleus and all the
When you contract a fever, your When you contract a fever, your body temperature is elevated. body temperature is elevated.
Is fever and inadvertent Is fever and inadvertent consequence of the infection or is it consequence of the infection or is it an example of homeostasis?an example of homeostasis?
Each of you has been vaccinated for Each of you has been vaccinated for multiple childhood diseases. You may multiple childhood diseases. You may or may not have taken a flu vaccine.or may not have taken a flu vaccine.
Explain how membrane and Explain how membrane and information attributes of living systems information attributes of living systems underpin the efficacy of vaccinations.underpin the efficacy of vaccinations.