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Chemistry Comes Chemistry Comes AliveAlive
The Chemistry of LifeThe Chemistry of Life
Atoms, Ions and MoleculesAtoms, Ions and Molecules Water and MixturesWater and Mixtures Energy and Chemical ReactionsEnergy and Chemical Reactions Organic compoundsOrganic compounds
MatterMatter
The “stuff” of the universeThe “stuff” of the universe Anything that has mass and takes up Anything that has mass and takes up
spacespace States of matterStates of matter
Solid – has definite shape and volumeSolid – has definite shape and volume Liquid – has definite volume, changeable Liquid – has definite volume, changeable
shapeshape Gas – has changeable shape and volumeGas – has changeable shape and volume
The Chemical ElementsThe Chemical Elements
Element Element simplest form of matter with unique simplest form of matter with unique
chemical propertieschemical properties
Each element has unique physical and Each element has unique physical and chemical propertieschemical properties Physical properties – those detected with Physical properties – those detected with
our sensesour senses Chemical properties – pertain to the way Chemical properties – pertain to the way
atoms interact with one anotheratoms interact with one another
Major Elements of the Major Elements of the Human BodyHuman Body
98.5% of body weight consists of98.5% of body weight consists of Oxygen (O)Oxygen (O) Carbon (C)Carbon (C) Hydrogen (H)Hydrogen (H) Nitrogen (N)Nitrogen (N)
Lesser and Trace Lesser and Trace Elements of the Human Elements of the Human
BodyBody Lesser elements make up 3.9% of the Lesser elements make up 3.9% of the
body and include:body and include: Calcium (Ca), phosphorus (P), potassium Calcium (Ca), phosphorus (P), potassium
(K), sulfur (S), sodium (Na), chlorine (Cl), (K), sulfur (S), sodium (Na), chlorine (Cl), magnesium (Mg), iodine (I), and iron (Fe)magnesium (Mg), iodine (I), and iron (Fe)
Trace elements make up less than Trace elements make up less than 0.01% of the body0.01% of the body They are required in minute amounts, They are required in minute amounts,
and are found as part of enzymesand are found as part of enzymes
Periodic Table of the Periodic Table of the ElementsElements
Atomic number of each elementAtomic number of each element number of protons in its nucleusnumber of protons in its nucleus
Periodic table Periodic table letter symbols of elements arranged by letter symbols of elements arranged by
atomic numberatomic number
http://pearl1.lanl.gov/periodic/default.htm
AtomicAtomic Structure Structure
Nucleus - center of atom containsNucleus - center of atom contains protons: positive charge, mass of 1 amuprotons: positive charge, mass of 1 amu neutrons: neutral charge, mass of 1 amuneutrons: neutral charge, mass of 1 amu atomic mass = total # of protons + neutronsatomic mass = total # of protons + neutrons
Electron shells Electron shells electrons: negative chargeelectrons: negative charge # of electrons = # of protons, atoms have neutral # of electrons = # of protons, atoms have neutral
chargecharge electrons further from nucleus have higher energyelectrons further from nucleus have higher energy valence electrons are in the outermost shellvalence electrons are in the outermost shell
interact with other atomsinteract with other atoms determine chemical behaviordetermine chemical behavior octet rule - atoms react to obtain a stable number of 8 octet rule - atoms react to obtain a stable number of 8
valence electronsvalence electrons
Bohr Planetary Model of an Bohr Planetary Model of an AtomAtom
Models of Some ElementsModels of Some Elements
p+ represents protons, no represents neutrons
Isotopes and RadioactivityIsotopes and Radioactivity IsotopesIsotopes
elements that differ in the number of neutronselements that differ in the number of neutrons 11H, H, 22H, H, 33HH
extra neutrons result in increased atomic weightextra neutrons result in increased atomic weight ““heavy water”heavy water”
have have nono change in change in chemicalchemical behavior behavior same valence electronssame valence electrons
Atomic weightAtomic weight AverageAverage atomic mass of the mixture of isotopes atomic mass of the mixture of isotopes
of an element found in a sampleof an element found in a sample
Isotopes of HydrogenIsotopes of Hydrogen
Figure 2.3
–radioisotopes decay to stable isotopes releasing radiation–radioisotopes decay to stable isotopes releasing radiation
Radioisotopes and Radioisotopes and RadioactivityRadioactivity
Isotopes Isotopes same chemical same chemical
behavior, differ in behavior, differ in physical behaviorphysical behavior
Radioisotopes Radioisotopes unstable isotopesunstable isotopes
Radioactivity Radioactivity radioisotopes decay radioisotopes decay
to stable isotopes to stable isotopes releasing radiationreleasing radiation
Marie Curie
High energyHigh energy Ejects electrons from atomsEjects electrons from atoms Destroys molecules and produces free radicalsDestroys molecules and produces free radicals
sources include:sources include: UV light, X rays, nuclear decay (UV light, X rays, nuclear decay (, , , , ))
particle - particle - 2 protons + 2 neutrons can’t penetrate skin2 protons + 2 neutrons can’t penetrate skin
particle -particle - free electron - penetrates skin a few millimetersfree electron - penetrates skin a few millimeters
particle -particle - high energy, penetrating; very dangeroushigh energy, penetrating; very dangerous
Ionizing RadiationIonizing Radiation
Physical half-lifePhysical half-life time for 50% of atoms to decaytime for 50% of atoms to decay 9090Sr - 28 yr.Sr - 28 yr. 4040K - 1.3 billion yearsK - 1.3 billion years
Biological half-lifeBiological half-life time for 50% of atoms to disappear from the bodytime for 50% of atoms to disappear from the body function of decay and physiological clearancefunction of decay and physiological clearance
Cesium 137 - physical half-life -- 30 years Cesium 137 - physical half-life -- 30 years - biological half-life -- 17 - biological half-life -- 17
daysdays
Radiation exposureRadiation exposure background radiationbackground radiation
radon gas from decay of uranium in graniteradon gas from decay of uranium in granite cosmic rayscosmic rays
Ionizing Radiation 2Ionizing Radiation 2
Molecules and Chemical Molecules and Chemical BondsBonds
MoleculesMolecules two or more atoms of same element two or more atoms of same element
covalently bondedcovalently bonded
CompoundsCompounds two or more atoms of different elements two or more atoms of different elements
covalently bondedcovalently bonded
Molecular formula Molecular formula itemizes each element present and its itemizes each element present and its
quantityquantity Structural formulaStructural formula
shows arrangement of atomsshows arrangement of atoms needed to show structural isomersneeded to show structural isomers
Concentration of Concentration of SolutionsSolutions
Percent, or parts per 100 partsPercent, or parts per 100 parts Molarity, or moles per liter (Molarity, or moles per liter (MM))
Mole – Avagadro’s number of moleculesMole – Avagadro’s number of molecules 6.02 X 106.02 X 1023 23
A mole of an element or compound is A mole of an element or compound is equal to its atomic or molecular equal to its atomic or molecular weight (sum of atomic weights) in weight (sum of atomic weights) in gramsgrams
Types of Chemical BondsTypes of Chemical Bonds
Ionic Ionic Covalent Covalent HydrogenHydrogen
Chemical BondsChemical Bonds Electron shells, or energy levels, surround Electron shells, or energy levels, surround
the nucleus of an atomthe nucleus of an atom Bonds are formed using the electrons in Bonds are formed using the electrons in
the outermost energy levelthe outermost energy level Valence shell – outermost energy level Valence shell – outermost energy level
containing chemically active electronscontaining chemically active electrons Octet rule – except for the first shell which Octet rule – except for the first shell which
is full with two electrons, atoms interact in is full with two electrons, atoms interact in a manner to have eight electrons in their a manner to have eight electrons in their valence shellvalence shell
Chemically Inert Chemically Inert ElementsElements Inert elements have their outermost energy level Inert elements have their outermost energy level
fully occupied by electronsfully occupied by electrons
Figure 2.4a
Chemically Reactive Chemically Reactive ElementsElements
Reactive Reactive elements do elements do not have their not have their outermost outermost energy level energy level fully occupied fully occupied by electronsby electrons
Figure 2.4b
Ions - carry a charge, unequal Ions - carry a charge, unequal numbers of protons and electronsnumbers of protons and electrons
Ionization - Ionization - transfer of transfer of electrons from one electrons from one atom to another (atom to another ( stability of valence stability of valence shell)shell)
IonsIons
Anion - atom gained electron, net negative chargeAnion - atom gained electron, net negative charge Cation - atom lost an electron, net positive chargeCation - atom lost an electron, net positive charge
Anions and CationsAnions and Cations
Ionic BondsIonic Bonds
Attraction of oppositely charged ions to each other Attraction of oppositely charged ions to each other forms an ionic bond - no sharing of electronsforms an ionic bond - no sharing of electrons
Ionic bonds are weak and dissociate in waterIonic bonds are weak and dissociate in water These compounds tend to form crystals...These compounds tend to form crystals...
Formation of an Ionic Formation of an Ionic BondBond
Figure 2.5a
Covalent BondsCovalent Bonds Formed by sharing Formed by sharing
valence electronsvalence electrons Types of covalent Types of covalent
bondsbonds single covalent single covalent
bondbond
double covalent double covalent bondbond
Triple covalent Triple covalent bondbond
Polar and Nonpolar Polar and Nonpolar MoleculesMolecules
Electrons shared equally between Electrons shared equally between atoms produce nonpolar moleculesatoms produce nonpolar molecules
Unequal sharing of electrons Unequal sharing of electrons produces polar moleculesproduces polar molecules
Atoms with six or seven valence shell Atoms with six or seven valence shell electrons are electronegativeelectrons are electronegative
Atoms with one or two valence shell Atoms with one or two valence shell electrons are electropositiveelectrons are electropositive
Figure 2.8
Comparison of Ionic, Polar Comparison of Ionic, Polar Covalent, and Nonpolar Covalent, and Nonpolar
Covalent BondsCovalent Bonds
Hydrogen BondsHydrogen Bonds
Weakest of the bondsWeakest of the bonds Attraction between polar molecules – no Attraction between polar molecules – no
sharing of electronssharing of electrons Greatest physiological importanceGreatest physiological importance
properties of waterproperties of water shapes of complex moleculesshapes of complex molecules
proteins, DNAproteins, DNA
Hydrogen Bonding in WaterHydrogen Bonding in Water
The Chemistry of LifeThe Chemistry of Life
Atoms, Ions and MoleculesAtoms, Ions and Molecules Water and MixturesWater and Mixtures Energy and Chemical ReactionsEnergy and Chemical Reactions Organic compoundsOrganic compounds
Adhesion and CohesionAdhesion and Cohesion
Adhesion - attraction between one Adhesion - attraction between one substance and another substancesubstance and another substance
Cohesion - attraction between one Cohesion - attraction between one substance and itselfsubstance and itself water is very cohesive due to hydrogen water is very cohesive due to hydrogen
bondsbonds Surface tension Surface tension
elastic surface film caused by the attraction elastic surface film caused by the attraction of molecules at the surface from those of molecules at the surface from those belowbelow
Thermal Stability of Thermal Stability of WaterWater
Heat capacityHeat capacity: amount of heat required to : amount of heat required to raise the temperature of 1g of a raise the temperature of 1g of a substancesubstance by 1°Cby 1°C
CalorieCalorie: amount of heat required to raise the : amount of heat required to raise the temperature of 1g of temperature of 1g of waterwater by 1°C by 1°C
Water stabilizes internal temperature of the Water stabilizes internal temperature of the bodybody high heat capacityhigh heat capacity
its hydrogen bonds inhibit increased temperature its hydrogen bonds inhibit increased temperature (molecular motion) caused by increased heat(molecular motion) caused by increased heat
effective coolanteffective coolant 1 ml of perspiration removes 500 calories from the body 1 ml of perspiration removes 500 calories from the body
Properties of WaterProperties of Water
Reactivity – is an important part of Reactivity – is an important part of hydrolysis and dehydration synthesis hydrolysis and dehydration synthesis reactionsreactions
Cushioning – resilient cushion around Cushioning – resilient cushion around certain body organscertain body organs
InterActive Physiology®: Fluid, Electrolyte, and Acid/Base Balance: Introduction to Body FluidsPLAYPLAY
Mixtures and SolutionsMixtures and Solutions
Mixtures – two or more components Mixtures – two or more components physically intermixed (not chemically physically intermixed (not chemically bonded)bonded)
Solutions – homogeneous mixtures of Solutions – homogeneous mixtures of componentscomponents Solvent – substance present in greatest Solvent – substance present in greatest
amountamount Solute – substance(s) present in smaller Solute – substance(s) present in smaller
amountsamounts
SolvencySolvency
Solvency - ability to dissolve matterSolvency - ability to dissolve matter Hydrophilic - charged substances that Hydrophilic - charged substances that
dissolve easily in waterdissolve easily in water Hydrophobic - neutral substances that Hydrophobic - neutral substances that
do not easily dissolve in waterdo not easily dissolve in water Water is the universal solvent, important Water is the universal solvent, important
for metabolic reactions and transport of for metabolic reactions and transport of substancessubstances
Water as a SolventWater as a Solvent
Water molecules overpower the ionic bond above Water molecules overpower the ionic bond above between Nabetween Na++ClCl- - by forming hydration spheres. by forming hydration spheres.
Note orientation of water molecules: negative pole Note orientation of water molecules: negative pole faces Nafaces Na++, positive pole faces Cl, positive pole faces Cl- -
MixturesMixtures
Substances that Substances that are physically are physically blended but not blended but not chemically chemically combinedcombined
SolutionsSolutions ColloidsColloids SuspensionsSuspensions
SolutionsSolutions
Solute < 1nmSolute < 1nm pass through pass through
membranesmembranes TransparentTransparent e.g. copper sulfate e.g. copper sulfate
solutionsolution
ColloidsColloids
Particles 1 to Particles 1 to 100nm100nm to large to pass to large to pass
through through membranesmembranes
CloudyCloudy e.g. milk proteine.g. milk protein
SuspensionsSuspensions
Particles >100nmParticles >100nm Cloudy or opaqueCloudy or opaque Separate on Separate on
standingstanding e.g. blood cellse.g. blood cells
Measures of Measures of ConcentrationConcentration
Weight per VolumeWeight per Volume weight of solute in a given volume of weight of solute in a given volume of
solutionsolution e.g. IV saline contains 8.5 g/L NaCle.g. IV saline contains 8.5 g/L NaCl
PercentagesPercentages weight or volume of solute in solutionweight or volume of solute in solution
e.g. IV D5W (5% w/v dextrose in distilled water)e.g. IV D5W (5% w/v dextrose in distilled water) 5 grams of dextrose in add 100ml water5 grams of dextrose in add 100ml water
MolarityMolarity number of moles of solute/liter in solutionnumber of moles of solute/liter in solution physiologic effects of a chemical based on physiologic effects of a chemical based on
the number of molecules in solutionthe number of molecules in solution
SaltsSalts
Inorganic compoundsInorganic compounds Contain cations other than HContain cations other than H++ and and
anions other than OHanions other than OH––
Are electrolytes; they conduct Are electrolytes; they conduct electrical currentselectrical currents
Acids and BasesAcids and Bases
Acids release HAcids release H+ + and are therefore and are therefore proton donorsproton donors
HCl HCl H H+ + + Cl+ Cl – –
Bases release OHBases release OH–– and are proton and are proton acceptorsacceptors
NaOH NaOH Na Na+ + + OH+ OH––
Acid-Base Concentration Acid-Base Concentration (pH)(pH)
Acidic solutions have higher HAcidic solutions have higher H++ concentration and therefore a lower concentration and therefore a lower pHpH
Alkaline solutions have lower HAlkaline solutions have lower H+ +
concentration and therefore a higher concentration and therefore a higher pHpH
Neutral solutions have equal HNeutral solutions have equal H+ + and and OHOH–– concentrations concentrations
pHpH pH - based on the molarity of HpH - based on the molarity of H++ on a on a
logarithmic scalelogarithmic scale pH = -log [HpH = -log [H++]] for molarity of Hfor molarity of H++ = 10 = 1000,10,10-1-1,10,10-2-2,etc.,etc.
pH = - log [10pH = - log [1000] = 0, - log [10] = 0, - log [10-1-1] = 1, etc.] = 1, etc. a change of one number on the pH scale a change of one number on the pH scale
therefore represents a 10 fold change in therefore represents a 10 fold change in HH++ concentration concentration
Our body uses buffers to resist any Our body uses buffers to resist any change in pHchange in pH
pH ScalepH Scale
BuffersBuffers
Systems that resist abrupt and large Systems that resist abrupt and large swings in the pH of body fluidsswings in the pH of body fluids
Carbonic acid-bicarbonate systemCarbonic acid-bicarbonate system Carbonic acid dissociates, reversibly Carbonic acid dissociates, reversibly
releasing bicarbonate ions and protonsreleasing bicarbonate ions and protons The chemical equilibrium between The chemical equilibrium between
carbonic acid and bicarbonate resists pH carbonic acid and bicarbonate resists pH changes in the bloodchanges in the blood
InterActive Physiology®: Fluid, Electrolyte, and Acid/Base Balance: Acid/Base HomeostasisPLAYPLAY
The Chemistry of LifeThe Chemistry of Life
Atoms, Ions and MoleculesAtoms, Ions and Molecules Water and MixturesWater and Mixtures Energy and Chemical ReactionsEnergy and Chemical Reactions Organic compoundsOrganic compounds
Work and EnergyWork and Energy Energy - the capacity to do workEnergy - the capacity to do work Kinetic energy - energy of motionKinetic energy - energy of motion Potential energy- inherent energy Potential energy- inherent energy
due to an objects position or due to an objects position or internal stateinternal state
Chemical energy - potential energy Chemical energy - potential energy stored in the molecular bondsstored in the molecular bonds
Electromagnetic energy - kinetic Electromagnetic energy - kinetic energy of photons: energy of photons: light, infrared, UV, X rays + light, infrared, UV, X rays + rays rays
Chemical ReactionsChemical Reactions
Occur when chemical bonds are Occur when chemical bonds are formed, rearranged, or brokenformed, rearranged, or broken
Are written in symbolic form using Are written in symbolic form using chemical equationschemical equations
Chemical equations contain:Chemical equations contain: Number and type of reacting Number and type of reacting
substances, and products producedsubstances, and products produced Relative amounts of reactants and Relative amounts of reactants and
productsproducts
Examples of Chemical Examples of Chemical ReactionsReactions
Patterns of Chemical Patterns of Chemical ReactionsReactions
Combination reactions:Combination reactions: Synthesis Synthesis reactions which always involve bond reactions which always involve bond formationformation
A + B A + B AB AB
Decomposition reactions: Molecules are Decomposition reactions: Molecules are broken down into smaller molecules broken down into smaller molecules
AB AB A + B A + B
Exchange reactions: Bonds are both made Exchange reactions: Bonds are both made and brokenand broken
AB + C AB + C AC + B AC + B
Energy Flow in Chemical Energy Flow in Chemical ReactionsReactions
Exergonic reactions – reactions that Exergonic reactions – reactions that release energyrelease energy
Endergonic reactions – reactions Endergonic reactions – reactions whose products contain more whose products contain more potential energy than did its potential energy than did its reactantsreactants
MetabolismMetabolism
All the chemical reactions of the bodyAll the chemical reactions of the body CatabolismCatabolism
energy releasing (exergonic) energy releasing (exergonic) decomposition reactionsdecomposition reactions
AnabolismAnabolism energy releasing (endergonic) synthesis energy releasing (endergonic) synthesis
reactionsreactions
Reaction RatesReaction Rates
Basis for chemical reactions is molecular Basis for chemical reactions is molecular motion and collisionsmotion and collisions
Reaction Rates affected by:Reaction Rates affected by: concentrationconcentration
more concentrated, more collisions, faster rxmore concentrated, more collisions, faster rx temperaturetemperature
higher temperature, greater collision force, faster rxhigher temperature, greater collision force, faster rx catalystscatalysts
speed up reactions without permanent change to speed up reactions without permanent change to itselfitself
biological catalysts are enzymesbiological catalysts are enzymes
Oxidation-Reduction Oxidation-Reduction (Redox) Reactions(Redox) Reactions
Reactants losing electrons are Reactants losing electrons are electron donors and are oxidizedelectron donors and are oxidized
Reactants taking up electrons are Reactants taking up electrons are electron acceptors and become electron acceptors and become reducedreduced
Energy Flow in Chemical Energy Flow in Chemical ReactionsReactions
Exergonic reactions – reactions that Exergonic reactions – reactions that release energyrelease energy
Endergonic reactions – reactions Endergonic reactions – reactions whose products contain more whose products contain more potential energy than did its potential energy than did its reactantsreactants
The Chemistry of LifeThe Chemistry of Life
Atoms, Ions and MoleculesAtoms, Ions and Molecules Water and MixturesWater and Mixtures Energy and Chemical ReactionsEnergy and Chemical Reactions Organic compoundsOrganic compounds
Organic CompoundsOrganic Compounds
Molecules unique to living systems Molecules unique to living systems contain carbon and hence are contain carbon and hence are organic compoundsorganic compounds
They include:They include: CarbohydratesCarbohydrates LipidsLipids ProteinsProteins Nucleic AcidsNucleic Acids
Organic Molecules: Organic Molecules: CarbonCarbon
Bonds readily with other carbon atoms, Bonds readily with other carbon atoms, hydrogen, oxygen, nitrogen, sulfur hydrogen, oxygen, nitrogen, sulfur needs 4 more valence electronsneeds 4 more valence electrons
Can form rings or long carbon chains Can form rings or long carbon chains that serve as the backbone for organic that serve as the backbone for organic moleculesmolecules
Groups of atoms Groups of atoms attach to carbon attach to carbon backbonebackbone
Determine the Determine the properties of organic properties of organic moleculesmolecules
Functional Groups Functional Groups
Monomers and PolymersMonomers and Polymers Monomers Monomers
subunits of macromoleculessubunits of macromolecules DNA has 4 different monomers (nucleotides)DNA has 4 different monomers (nucleotides) proteins have 20 different monomers (amino proteins have 20 different monomers (amino
acids)acids) PolymersPolymers
series of monomers bonded togetherseries of monomers bonded together PolymerizationPolymerization
the bonding of monomers together to form the bonding of monomers together to form a polymera polymer
caused by a reaction called dehydration caused by a reaction called dehydration synthesissynthesis
Monomers and PolymersMonomers and Polymers Monomers Monomers
subunits of macromoleculessubunits of macromolecules DNA has 4 different monomers (nucleotides)DNA has 4 different monomers (nucleotides) proteins have 20 different monomers (amino proteins have 20 different monomers (amino
acids)acids) PolymersPolymers
series of monomers bonded togetherseries of monomers bonded together PolymerizationPolymerization
the bonding of monomers together to form the bonding of monomers together to form a polymera polymer
caused by a reaction called dehydration caused by a reaction called dehydration synthesissynthesis
HydrolysisHydrolysis Splitting a polymer (lysis) by the addition Splitting a polymer (lysis) by the addition
of a water molecule (hydro)of a water molecule (hydro) Digestion consists of hydrolysis reactionsDigestion consists of hydrolysis reactions
CarbohydratesCarbohydrates
Figure 2.13a
Contain carbon, hydrogen, and oxygenContain carbon, hydrogen, and oxygen Their major function is to supply a Their major function is to supply a
source of cellular foodsource of cellular food ExamplesExamples::
Monosaccharides or simple sugarsMonosaccharides or simple sugars
Organic Molecules: Organic Molecules: CarbohydratesCarbohydrates
Hydrophilic organic moleculeHydrophilic organic molecule General formula General formula
(CH(CH22O)O)n n , n = number of carbon atoms, n = number of carbon atoms
for glucose, n = 6, so formula is Cfor glucose, n = 6, so formula is C66HH1212OO66
Names of carbohydratesNames of carbohydrates word root word root saccharsacchar- or the suffix -- or the suffix -ose ose often often
usedused monosaccharide or glucosemonosaccharide or glucose
MonosaccharidesMonosaccharides Simplest carbohydratesSimplest carbohydrates General formula is CGeneral formula is C66HH1212OO66
structural isomersstructural isomers
Three major monosaccharidesThree major monosaccharides glucose, galactose and fructoseglucose, galactose and fructose mainly produced by digestion of mainly produced by digestion of
complex carbohydratescomplex carbohydrates
DisaccharidesDisaccharides
Pairs of Pairs of monosaccharidesmonosaccharides
Three major Three major disaccharidesdisaccharides sucrose sucrose
glucose + fructoseglucose + fructose lactoselactose
glucose + galactoseglucose + galactose maltosemaltose
glucose + glucoseglucose + glucose
PolysaccharidesPolysaccharides Starch, cellulose and glycogen Starch, cellulose and glycogen
long chains of glucose form these polysaccharideslong chains of glucose form these polysaccharides Starch produced by plants is digested by amylaseStarch produced by plants is digested by amylase Cellulose gives structure to plants, fiber to our Cellulose gives structure to plants, fiber to our
dietdiet
PolysaccharidesPolysaccharides Glycogen is an energy storage Glycogen is an energy storage
polysaccharide produced by animals polysaccharide produced by animals Liver cells synthesize glycogen after a Liver cells synthesize glycogen after a
meal to maintain blood glucose levelsmeal to maintain blood glucose levels
Carbohydrate Carbohydrate FunctionsFunctions
Source of energySource of energy Conjugated carbohydratesConjugated carbohydrates
glycolipids glycolipids external surface of cell membraneexternal surface of cell membrane
glycoproteinsglycoproteins external surface of cell membraneexternal surface of cell membrane mucus of respiratory and digestive tractsmucus of respiratory and digestive tracts
proteoglycansproteoglycans carbohydrate component dominantcarbohydrate component dominant cell adhesion, gelatinous filler of tissues (eye) cell adhesion, gelatinous filler of tissues (eye)
and lubricates jointsand lubricates joints
LipidsLipids
Contain C, H, and O, but the Contain C, H, and O, but the proportion of oxygen in lipids is less proportion of oxygen in lipids is less than in carbohydratesthan in carbohydrates
Examples:Examples: Neutral fats or triglyceridesNeutral fats or triglycerides PhospholipidsPhospholipids SteroidsSteroids EicosanoidsEicosanoids
Fatty AcidsFatty Acids
Chain of usually 4 to 24 carbon atomsChain of usually 4 to 24 carbon atoms
Carboxyl (acid) groupCarboxyl (acid) group on one end and on one end and a a methyl groupmethyl group on the other on the other
Polymers of two-carbon Polymers of two-carbon acetylacetyl groups groups
Fatty AcidsFatty Acids Saturated fatty acid - carbon atoms Saturated fatty acid - carbon atoms
saturated with hydrogen saturated with hydrogen Unsaturated fatty acid - contains C=C Unsaturated fatty acid - contains C=C
bonds that could bond more hydrogen bonds that could bond more hydrogen
Fatty AcidsFatty Acids Saturated fatty acid - carbon atoms Saturated fatty acid - carbon atoms
saturated with hydrogen saturated with hydrogen Unsaturated fatty acid - contains C=C Unsaturated fatty acid - contains C=C
bonds that could bond more hydrogen bonds that could bond more hydrogen
Triglyceride Synthesis Triglyceride Synthesis (2)(2)
Triglycerides called neutral fatsTriglycerides called neutral fats fatty acids bond with their carboxyl ends, therefore fatty acids bond with their carboxyl ends, therefore
no longer acidicno longer acidic
TriglyceridesTriglycerides
Hydrolysis of fats occurs by lipase Hydrolysis of fats occurs by lipase enzymeenzyme
Triglycerides at room temperatureTriglycerides at room temperature liquid called oils, often polyunsaturated fats liquid called oils, often polyunsaturated fats
from plantsfrom plants solid called fat, saturated fats from animalssolid called fat, saturated fats from animals
Function - energy storageFunction - energy storage also insulation and shock absorption for also insulation and shock absorption for
organsorgans
PhospholipidsPhospholipids
Amphiphilic characterAmphiphilic character Hydrophobic “tails” similar to neutral Hydrophobic “tails” similar to neutral
fats with two fatty acids attached to fats with two fatty acids attached to glycerolglycerol
Hydrophilic “head” differs from neutral Hydrophilic “head” differs from neutral fat with the third fatty acid replaced with fat with the third fatty acid replaced with a phosphate group attached to other a phosphate group attached to other functional groupsfunctional groups
A Phospholipid - A Phospholipid - LecithinLecithin
SteroidsSteroids
CholesterolCholesterol other steroids derive from cholesterolother steroids derive from cholesterol
cortisol, progesterone, estrogens, cortisol, progesterone, estrogens, testosterone and bile acidstestosterone and bile acids
required for proper nervous system required for proper nervous system function and is an important component function and is an important component of cell membranes of cell membranes
produced only by animalsproduced only by animals 85% naturally produced by our body 85% naturally produced by our body only 15% derived from our dietonly 15% derived from our diet
EicosanoidsEicosanoids Derived from arachidonic acid (a fatty acid)Derived from arachidonic acid (a fatty acid) Function as chemical signals between cellsFunction as chemical signals between cells Includes prostaglandins Includes prostaglandins
role in inflammation, blood clotting, hormone action, role in inflammation, blood clotting, hormone action, labor contractions, control of blood vessel diameterlabor contractions, control of blood vessel diameter
CholesterolCholesterol All steroids have this 4 ringed structure All steroids have this 4 ringed structure
with variations in the functional groups with variations in the functional groups and location of double bondsand location of double bonds
Representative Lipids Representative Lipids Found in the BodyFound in the Body
Neutral fats – found in subcutaneous tissue Neutral fats – found in subcutaneous tissue and around organsand around organs
Phospholipids – chief component of cell Phospholipids – chief component of cell membranesmembranes
Steroids – cholesterol, bile salts, vitamin D, Steroids – cholesterol, bile salts, vitamin D, sex hormones, and adrenal cortical hormonessex hormones, and adrenal cortical hormones
Fat-soluble vitamins – vitamins A, E, and KFat-soluble vitamins – vitamins A, E, and K Eicosanoids – prostaglandins, leukotriens, Eicosanoids – prostaglandins, leukotriens,
and thromboxanesand thromboxanes Lipoproteins – transport fatty acids and Lipoproteins – transport fatty acids and
cholesterol in the bloodstream cholesterol in the bloodstream
Polymer of amino acidsPolymer of amino acids
Organic Molecules: Organic Molecules: ProteinsProteins
20 amino acids20 amino acids identical except for -R identical except for -R
group attached to central group attached to central carboncarbon
amino acid properties amino acid properties determined by -R groupdetermined by -R group
The amino acids in a The amino acids in a protein determine its protein determine its structure and functionstructure and function
Amino AcidsAmino Acids
Building blocks of protein, containing Building blocks of protein, containing an amino group and a carboxyl groupan amino group and a carboxyl group
Amino acid structureAmino acid structure
InterActive Physiology®: Fluid, Electrolyte, and Acid/Base Balance: Introduction to Body FluidsPLAYPLAY
Amino AcidsAmino Acids
Figure 2.15a-c
Amino AcidsAmino Acids
Figure 2.15d, e
PeptidesPeptides
A polymer of 2 or more amino acidsA polymer of 2 or more amino acids Named for the number of amino Named for the number of amino
acids they containacids they contain dipeptides have 2, tripeptides have 3dipeptides have 2, tripeptides have 3 oligopeptides have fewer than 10 to 15 oligopeptides have fewer than 10 to 15 polypeptides have more than 15polypeptides have more than 15 proteins have more than 100proteins have more than 100
Dehydration synthesis creates a Dehydration synthesis creates a peptide bond that joins amino acidspeptide bond that joins amino acids
Dipeptide SynthesisDipeptide Synthesis
ProteinProtein
Figure 2.16
Macromolecules composed of Macromolecules composed of combinations of 20 types of amino acids combinations of 20 types of amino acids bound together with peptide bondsbound together with peptide bonds
Structural Levels of Structural Levels of ProteinsProteins
Primary – amino acid sequencePrimary – amino acid sequence Secondary – alpha helices or beta Secondary – alpha helices or beta
pleated sheetspleated sheets
Chemistry of Life: Proteins: Secondary StructurePLAYPLAY
Structural Levels of Structural Levels of ProteinsProteins
Tertiary – superimposed folding of Tertiary – superimposed folding of secondary structuressecondary structures
Quaternary – polypeptide chains Quaternary – polypeptide chains linked together in a specific mannerlinked together in a specific manner
Chemistry of Life: Proteins: Quaternary StructurePLAYPLAY
Chemistry of Life: Proteins: Tertiary StructurePLAYPLAY
Fibrous and Globular Fibrous and Globular ProteinsProteins
Fibrous proteinsFibrous proteins Extended and strandlike proteins Extended and strandlike proteins Examples: keratin, elastin, collagen, and Examples: keratin, elastin, collagen, and
certain contractile fiberscertain contractile fibers Globular proteins Globular proteins
Compact, spherical proteins with tertiary Compact, spherical proteins with tertiary and quaternary structuresand quaternary structures
Examples: antibodies, hormones, and Examples: antibodies, hormones, and enzymesenzymes
Protein DenuaturationProtein Denuaturation
Figure 2.18a
Reversible Reversible unfolding of unfolding of proteins proteins due to due to drops in pH drops in pH and/or and/or increased increased temperaturtemperaturee
Protein DenuaturationProtein Denuaturation
Figure 2.18b
Irreversibly denatured proteins cannot refold and are Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature changesformed by extreme pH or temperature changes
Characteristics of Characteristics of EnzymesEnzymes
Most are globular proteins that act as Most are globular proteins that act as biological catalystsbiological catalysts
Holoenzymes consist of an apoenzyme Holoenzymes consist of an apoenzyme (protein) and a cofactor (usually an ion)(protein) and a cofactor (usually an ion)
Enzymes are chemically specificEnzymes are chemically specific Frequently named for the type of Frequently named for the type of
reaction they catalyzereaction they catalyze Enzyme names usually end in -Enzyme names usually end in -asease Lower activation energy Lower activation energy
Characteristics of EnzymesCharacteristics of Enzymes
Figure 2.19
Mechanism of Enzyme Mechanism of Enzyme ActionAction
Enzyme binds with substrateEnzyme binds with substrate Product is formed at a lower activation Product is formed at a lower activation
energyenergy Product is releasedProduct is released
How Enzymes WorkPLAYPLAY
Nucleic AcidsNucleic Acids
(C), thymine (T), and uracil (U) Composed (C), thymine (T), and uracil (U) Composed of carbon, oxygen, hydrogen, nitrogen, of carbon, oxygen, hydrogen, nitrogen, and phosphorusand phosphorus
Their structural unit, the nucleotide, is Their structural unit, the nucleotide, is composed of N-containing base, a pentose composed of N-containing base, a pentose sugar, and a phosphate groupsugar, and a phosphate group
Five nitrogen bases contribute to Five nitrogen bases contribute to nucleotide structure – adenine (A), nucleotide structure – adenine (A), guanine (G), cytosine guanine (G), cytosine
Two major classes – DNA and RNATwo major classes – DNA and RNA
Deoxyribonucleic Acid Deoxyribonucleic Acid (DNA)(DNA)
Double-stranded helical molecule Double-stranded helical molecule found in the nucleus of the cellfound in the nucleus of the cell
Replicates itself before the cell Replicates itself before the cell divides, ensuring genetic continuitydivides, ensuring genetic continuity
Provides instructions for protein Provides instructions for protein synthesissynthesis
Structure of DNAStructure of DNA
Figure 2.21a
Structure of DNAStructure of DNA
Figure 2.21b
Ribonucleic Acid (RNA)Ribonucleic Acid (RNA)
Single-stranded molecule found in Single-stranded molecule found in both the nucleus and the cytoplasm both the nucleus and the cytoplasm of a cellof a cell
Uses the nitrogenous base uracil Uses the nitrogenous base uracil instead of thymineinstead of thymine
Three varieties of RNA: messenger Three varieties of RNA: messenger RNA, transfer RNA, and ribosomal RNA, transfer RNA, and ribosomal RNARNA
Adenosine Triphosphate Adenosine Triphosphate (ATP)(ATP)
Source of immediately usable energy Source of immediately usable energy for the cellfor the cell
Adenine-containing RNA nucleotide Adenine-containing RNA nucleotide with three phosphate groupswith three phosphate groups
Adenosine Triphosphate Adenosine Triphosphate (ATP)(ATP)
Figure 2.22
How ATP Drives Cellular How ATP Drives Cellular WorkWork
Figure 2.23