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11
The Chemical ElementsThe Chemical Elements
Element = simplest form of matter with Element = simplest form of matter with unique chemical propertiesunique chemical properties
Atomic number = # of protons in nucleusAtomic number = # of protons in nucleus periodic table periodic table
• elements arranged by atomic numberelements arranged by atomic number 24 elements have biological role24 elements have biological role
• 6 elements = 98.5% of body weight 6 elements = 98.5% of body weight • Carbon, Hydrogen, Oxygen, NitrogenCarbon, Hydrogen, Oxygen, Nitrogen• trace elements in minute amountstrace elements in minute amounts
22
Terms to knowTerms to know ElementElement
matter composed of atoms that all have the same atomic number (protons). matter composed of atoms that all have the same atomic number (protons). AtomAtom
the smallest component of an element that still has properties of the element, the smallest component of an element that still has properties of the element, consisting of a positively charged nucleus surrounded by a charged cloud of consisting of a positively charged nucleus surrounded by a charged cloud of electrons. electrons.
"+" and "-" charges strongly attract. "+" and "-" charges strongly attract. ProtonProton
particle in the nucleus with a positive charge of +1 and an atomic mass number particle in the nucleus with a positive charge of +1 and an atomic mass number of 1 Dalton. of 1 Dalton.
NeutronNeutron a non-charged nuclear particle with the same mass as the proton. a non-charged nuclear particle with the same mass as the proton.
ElectronElectron negatively charged particle (-1) with a mass 1/1837 of that of a proton. negatively charged particle (-1) with a mass 1/1837 of that of a proton.
IsotopeIsotope atoms with the same number of protons and electrons, but different numbers of atoms with the same number of protons and electrons, but different numbers of
neutrons. neutrons.
33
Structure of an AtomStructure of an Atom Nucleus = center of atomNucleus = center of atom
protonsprotons neutronsneutrons
Electron shells surround the nucleusElectron shells surround the nucleus electrons: single negative charge, little masselectrons: single negative charge, little mass valence electrons in the outermost shellvalence electrons in the outermost shell
• interact with other atomsinteract with other atoms• determine chemical behaviordetermine chemical behavior
44
ElectrolytesElectrolytes
Salts that ionize in water to form body Salts that ionize in water to form body fluidsfluids capable of conducting electricitycapable of conducting electricity
Electrolyte importanceElectrolyte importance chemical reactivitychemical reactivity osmotic effects (influence water movement)osmotic effects (influence water movement) electrical effects on nerve and muscle tissueelectrical effects on nerve and muscle tissue
Imbalances cause muscle cramps, brittle Imbalances cause muscle cramps, brittle bones, coma and deathbones, coma and death
55
Free RadicalsFree Radicals Particle with an odd number of electronsParticle with an odd number of electrons Produced by Produced by
normal metabolic reactions, radiation, normal metabolic reactions, radiation, chemicals chemicals
Causes tissue damageCauses tissue damage reactions that destroy moleculesreactions that destroy molecules causes cancer, death of heart tissue and causes cancer, death of heart tissue and
agingaging
AntioxidantsAntioxidants neutralize free radicalsneutralize free radicals in diet (vitamin E, carotenoids, vitamin C)in diet (vitamin E, carotenoids, vitamin C)
66
Molecules and Chemical BondsMolecules and Chemical Bonds
MoleculesMolecules two or more atoms covalently bondedtwo or more atoms covalently bonded
CompoundsCompounds two or more atoms of different elements two or more atoms of different elements
covalently bondedcovalently bonded
Molecular formula Molecular formula elements and how many atoms of eachelements and how many atoms of each
Structural formulaStructural formula location of each atomlocation of each atom structural isomers revealedstructural isomers revealed
77
Chemical BondsChemical Bonds
Ionic bondsIonic bonds Covalent bondsCovalent bonds Hydrogen bondsHydrogen bonds Van der Waals forceVan der Waals force
88
Ionic BondsIonic Bonds
Attraction of oppositely charged ions Attraction of oppositely charged ions No sharing of electronsNo sharing of electrons Weak bond (easily dissociates in water)Weak bond (easily dissociates in water)
99
Covalent BondsCovalent Bonds Formed by sharing of valence electronsFormed by sharing of valence electrons Types of covalent bondsTypes of covalent bonds
single = sharing of single pair electronssingle = sharing of single pair electrons double = sharing of 2 pairsdouble = sharing of 2 pairs nonpolarnonpolar
• shared electrons (equal time around each nucleus)shared electrons (equal time around each nucleus)• strongest of all bondsstrongest of all bonds
polarpolar• negative charge where electrons spend most timenegative charge where electrons spend most time
1010
Properties of waterProperties of water
Terms we should knowTerms we should know Hydrophilic (charged substances) dissolve Hydrophilic (charged substances) dissolve
easily in watereasily in water Hydrophobic (neutral substances) do not Hydrophobic (neutral substances) do not
easily dissolve in watereasily dissolve in water Water = universal solventWater = universal solvent
metabolic reactions and transport of metabolic reactions and transport of substancessubstances
1111
Water as a SolventWater as a Solvent
Polar water molecules overpower the ionic Polar water molecules overpower the ionic bond in Nabond in Na++ClCl- -
forming hydration spheres around each ion forming hydration spheres around each ion
1212
Cohesiveness of waterCohesiveness of water
Cohesion – tendency of like molecules Cohesion – tendency of like molecules to cling to each otherto cling to each other water is very cohesive due to its hydrogen water is very cohesive due to its hydrogen
bondsbonds surface film on water formed by surface surface film on water formed by surface
tensiontension
1313
Chemical Reactivity of WaterChemical Reactivity of Water
Participation in chemical reactionsParticipation in chemical reactions water ionizes into Hwater ionizes into H++ and OH and OH--
water ionizes other chemicals (acids and water ionizes other chemicals (acids and salts)salts)
water involved in hydrolysis and water involved in hydrolysis and dehydration synthesis reactionsdehydration synthesis reactions
1414
Thermal Stability of WaterThermal Stability of Water
Water stabilizes internal temperature Water stabilizes internal temperature has high heat capacityhas high heat capacity
• hydrogen bonds inhibit temperature increases hydrogen bonds inhibit temperature increases by inhibiting molecular motionby inhibiting molecular motion
effective coolanteffective coolant• 1 ml of perspiration removes 500 calories1 ml of perspiration removes 500 calories
calorie: amount of heat required to raise temperature calorie: amount of heat required to raise temperature of 1g of water by 1°Cof 1g of water by 1°C
1515
SolutionsSolutions
Mixture of a solute Mixture of a solute into a solventinto a solvent
Small solute Small solute particles particles Can pass through Can pass through
cell membranescell membranes
1616
ColloidsColloids Mixture of protein Mixture of protein
and waterand water change from liquid change from liquid
to gel state within to gel state within and between cellsand between cells
Particles too large Particles too large to pass through cell to pass through cell membranesmembranes
CloudyCloudy Remains mixedRemains mixed
1717
MolarityMolarity
Molecular weight in grams = 1 mole of Molecular weight in grams = 1 mole of moleculesmolecules
1 mole = Avogadro’s number of 1 mole = Avogadro’s number of moleculesmolecules
Molarity is the number of moles of Molarity is the number of moles of solute/ liter of solutionsolute/ liter of solution MW of glucose is 180MW of glucose is 180 one-molar (1.0M) glucose solution one-molar (1.0M) glucose solution
contains 180g/L contains 180g/L
1818
Electrolyte ConcentrationsElectrolyte Concentrations
Effect the body chemically, physically and Effect the body chemically, physically and electricallyelectrically depends on charge and concentrationdepends on charge and concentration
Measured in equivalentsMeasured in equivalents 1 Eq will electrically neutralize 1 mole of H1 Eq will electrically neutralize 1 mole of H++ or OH or OH--
ionsions multiply molar concentration x valence of the ionmultiply molar concentration x valence of the ion 1 M Na1 M Na++ = 1 Eq/L = 1 Eq/L 1 M Ca1 M Ca2+2+ = 2 Eq/L = 2 Eq/L
1919
Acids, Bases and pHAcids, Bases and pH
An acid is proton donor (releases HAn acid is proton donor (releases H++ ions) ions) A base is proton acceptor (accepts HA base is proton acceptor (accepts H++ ions) ions) pH = the concentration of HpH = the concentration of H++ ions in ions in
solutionsolution a pH of less than 7 is acidic solutiona pH of less than 7 is acidic solution a pH of greater than 7 is basic solutiona pH of greater than 7 is basic solution a pH of 7.0 is neutral pHa pH of 7.0 is neutral pH
2020
pHpH
Our body uses buffers to prevent changeOur body uses buffers to prevent change pH of blood ranges from 7.35 to 7.45pH of blood ranges from 7.35 to 7.45 tremors, paralysis or even deathtremors, paralysis or even death
2222
Work and EnergyWork and Energy
Energy - capacity to do workEnergy - capacity to do work Kinetic energy - energy of motion Kinetic energy - energy of motion
heat is kinetic energy of molecular heat is kinetic energy of molecular motionmotion
Potential energy- energy due to Potential energy- energy due to object’s position (ions on one side object’s position (ions on one side only of cell membrane)only of cell membrane) chemical energy - potential energy chemical energy - potential energy
stored in the molecular bondsstored in the molecular bonds
2323
Chemical ReactionChemical Reaction Process that forms or breaks an Process that forms or breaks an
ionic or covalent bondionic or covalent bond Symbolized by chemical equationSymbolized by chemical equation
reactants reactants products products
Classes of reactionsClasses of reactions Decomposition reactionsDecomposition reactions Synthesis reactionsSynthesis reactions Exchange reactionsExchange reactions
2424
Decomposition Decomposition ReactionsReactions
Large molecules Large molecules broken down into broken down into smaller onessmaller ones
AB AB A + B A + B
2525
Synthesis Synthesis ReactionsReactions
Two or more small Two or more small molecules combine to molecules combine to form a larger oneform a larger one
A + B A + B AB AB
2626
Exchange ReactionsExchange Reactions Two molecules collide and exchange Two molecules collide and exchange
atoms or group of atomsatoms or group of atoms AB+CD AB+CD ABCD ABCD AC + BD AC + BD
2727
Reversible ReactionsReversible Reactions
Go in either direction (symbolized with Go in either direction (symbolized with double-headed arrow)double-headed arrow)
COCO22 + H + H22O HO H22COCO33 HCO HCO3-3- + H + H++
most common equation discussed in this most common equation discussed in this bookbook
Law of mass action determines Law of mass action determines directiondirection side of equation with greater quantity of side of equation with greater quantity of
reactants dominates reactants dominates
2828
Chemical BookkeepingChemical Bookkeeping
Chemical equation shows reactionChemical equation shows reaction
Reactants ---> ProductsReactants ---> Products Equation for photosynthesis:Equation for photosynthesis:
REACTANTS PRODUCTS
6CO2
CARBONDIOXIDE
12H2O
WATER
+ C6H12O6
GLUCOSE
6H2O
WATER
+
6 carbons12 oxygens
24 hydrogens12 oxygens
6 carbons12 hydrogens
6 oxygens
12 hydrogens6 oxygens
6O2
OXYGEN
+
12 oxygens
sunlightenergy
2929
Reaction RatesReaction Rates Basis for reactions is molecular motion and Basis for reactions is molecular motion and
collisionscollisions reactions occur when molecules collide with enough reactions occur when molecules collide with enough
force and the correct orientationforce and the correct orientation
Reaction Rates affected by:Reaction Rates affected by: concentrationconcentration
• more concentrated, more collisions, faster ratemore concentrated, more collisions, faster rate temperaturetemperature
• higher temperature, greater collision force, faster ratehigher temperature, greater collision force, faster rate Catalysts (enzymes)Catalysts (enzymes)
• speed up reactions without permanent change to itselfspeed up reactions without permanent change to itself• holds reactant molecules in correct orientationholds reactant molecules in correct orientation
3030
MetabolismMetabolism
All the chemical reactions of the bodyAll the chemical reactions of the body CatabolismCatabolism
energy releasing (exergonic) decomposition energy releasing (exergonic) decomposition reactionsreactions
• breaks covalent bonds, produces smaller molecules, breaks covalent bonds, produces smaller molecules, releases useful energyreleases useful energy
AnabolismAnabolism energy storing (endergonic) synthesis reactionsenergy storing (endergonic) synthesis reactions
• requires energy inputrequires energy input
3131
Oxidation-Reduction Oxidation-Reduction ReactionsReactions
Oxidation (LEO)Oxidation (LEO) molecule gives up electrons and releases energymolecule gives up electrons and releases energy accepting molecule is the oxidizing agentaccepting molecule is the oxidizing agent
• oxygen is often the electron acceptoroxygen is often the electron acceptor
Reduction (GER)Reduction (GER) molecule gains electrons and energymolecule gains electrons and energy donating molecule is the reducing agentdonating molecule is the reducing agent
Oxidation-reduction (redox) reactionsOxidation-reduction (redox) reactions Electrons are often transferred as hydrogen atomsElectrons are often transferred as hydrogen atoms
3232
Organic ChemistryOrganic Chemistry
Study of compounds containing carbonStudy of compounds containing carbon 4 categories of carbon compounds4 categories of carbon compounds
carbohydratescarbohydrates lipidslipids proteinsproteins nucleotides and nucleic acidsnucleotides and nucleic acids
3333
Organic Molecules and Organic Molecules and CarbonCarbon
Only 4 valence electronsOnly 4 valence electrons bonds readily to gain more valence bonds readily to gain more valence
electronselectrons Forms long chains, branched molecules Forms long chains, branched molecules
and ringsand rings serve as the backbone for organic serve as the backbone for organic
molecules molecules Carries a variety of functional groupsCarries a variety of functional groups
3434
Atoms attached to Atoms attached to carbon backbonecarbon backbone
Determines chemical Determines chemical propertiesproperties
Functional Groups Functional Groups
3535
Monomers and PolymersMonomers and Polymers
Macromolecules = very large moleculesMacromolecules = very large molecules Polymers = macromolecules formed Polymers = macromolecules formed
from monomers bonded together from monomers bonded together Monomers = an identical or similar Monomers = an identical or similar
subunitsubunit
3636
PolymerizationPolymerization
Bonding of monomers together to form Bonding of monomers together to form a polymera polymer
Formed by dehydration synthesisFormed by dehydration synthesis starch molecules are a polymer of 3000 starch molecules are a polymer of 3000
glucose monomersglucose monomers protein molecules are a polymer of amino protein molecules are a polymer of amino
acidsacids
3737
Dehydration SynthesisDehydration Synthesis Monomers covalently bond together to form a Monomers covalently bond together to form a
polymer with the removal of a water moleculepolymer with the removal of a water molecule A hydroxyl group is removed from one monomer A hydroxyl group is removed from one monomer
and a hydrogen from the nextand a hydrogen from the next
3838
HydrolysisHydrolysis Splitting a polymer (lysis) by the addition of a water Splitting a polymer (lysis) by the addition of a water
molecule (hydro)molecule (hydro) a covalent bond is brokena covalent bond is broken
All digestion reactions consists of hydrolysis All digestion reactions consists of hydrolysis reactionsreactions
3939
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
2:1 ratio of hydrogen to oxygen2:1 ratio of hydrogen to oxygen
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
4040
MonosaccharidesMonosaccharides
Simple sugarsSimple sugars
General formula is CGeneral formula is C66HH1212OO66
structural isomersstructural isomers
Major monosaccharidesMajor monosaccharides glucose, galactose and glucose, galactose and
fructosefructose produced by digestion of produced by digestion of
complex carbohydratescomplex carbohydrates• glucose is blood sugar glucose is blood sugar
4141
DisaccharidesDisaccharides Sugar molecule Sugar molecule
composed of 2 composed of 2 monosaccharidesmonosaccharides
Major disaccharidesMajor disaccharides sucrose = table sugarsucrose = table sugar
• glucose + fructoseglucose + fructose Lactose = sugar in milkLactose = sugar in milk
• glucose + galactoseglucose + galactose Maltose = grain productsMaltose = grain products
• glucose + glucoseglucose + glucose
4242
PolysaccharidesPolysaccharides Chains of glucose subunitsChains of glucose subunits Starch: energy storage in plantsStarch: energy storage in plants
digestible by humans for energydigestible by humans for energy
Cellulose: structural molecule of plant cell Cellulose: structural molecule of plant cell wallswalls fiber in our dietfiber in our diet
Glycogen: energy storage in animalsGlycogen: energy storage in animals liver synthesizes after a meal and breaks down liver synthesizes after a meal and breaks down
between mealsbetween meals
4444
Carbohydrate FunctionsCarbohydrate Functions All digested carbohydrates converted to glucose All digested carbohydrates converted to glucose
and oxidized to make ATPand oxidized to make ATP Conjugated carbohydrate = bound to lipid or Conjugated carbohydrate = bound to lipid or
proteinprotein 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• gels that hold cells and tissues togethergels that hold cells and tissues together• joint lubricationjoint lubrication• rubbery texture of cartilagerubbery texture of cartilage
4545
Organic Molecules: LipidsOrganic Molecules: Lipids Hydrophobic organic moleculeHydrophobic organic molecule
composed of carbon, hydrogen and oxygencomposed of carbon, hydrogen and oxygen Less oxidized and thus has more Less oxidized and thus has more
calories/gramcalories/gram Five primary types in humansFive primary types in humans
fatty acidsfatty acids triglyceridestriglycerides phospholipidsphospholipids eicosanoidseicosanoids steroidssteroids
4646
Fatty AcidsFatty Acids Chain of 4 to 24 carbon atomsChain of 4 to 24 carbon atoms
carboxyl (acid) group on one end, methyl group on the other carboxyl (acid) group on one end, methyl group on the other and hydrogen bonded along the sidesand hydrogen bonded along the sides
Classified Classified saturated - carbon atoms saturated with hydrogen saturated - carbon atoms saturated with hydrogen unsaturated - contains C=C bonds without hydrogenunsaturated - contains C=C bonds without hydrogen
4747
Triglycerides (Neutral Fats)Triglycerides (Neutral Fats)
3 fatty acids bonded to glycerol molecule 3 fatty acids bonded to glycerol molecule (dehydration synthesis)(dehydration synthesis)
At room temperatureAt room temperature when liquid called oilswhen liquid called oils
• often polyunsaturated fats from plantsoften polyunsaturated fats from plants when solid called fatwhen solid called fat
• saturated fats from animalssaturated fats from animals
Function - energy storage, insulation and Function - energy storage, insulation and shock absorptionshock absorption
4848
PhospholipidsPhospholipids Triglyceride with one fatty acid replaced by a Triglyceride with one fatty acid replaced by a
phosphate groupphosphate group Amphiphilic characterAmphiphilic character
fatty acid “tails” are hydrophobicfatty acid “tails” are hydrophobic Phosphate “head” is hydrophilicPhosphate “head” is hydrophilic
4949
EicosanoidsEicosanoids
Derived from arachidonic acid (a fatty acid)Derived from arachidonic acid (a fatty acid) Hormone-like chemical signals between cellsHormone-like chemical signals between cells Includes prostaglandins – produced in all Includes prostaglandins – produced in all
tissuestissues role in inflammation, blood clotting, hormone role in inflammation, blood clotting, hormone
action, labor contractions, blood vessel diameteraction, labor contractions, blood vessel diameter
5050
Steroids and CholesterolSteroids and Cholesterol
Steroid = lipid with carbon atoms in Steroid = lipid with carbon atoms in four ringsfour rings all steroids are derived from cholesterolall steroids are derived from cholesterol
• cortisol, progesterone, estrogens, testosterone cortisol, progesterone, estrogens, testosterone and bile acidsand bile acids
Cholesterol Cholesterol important component of cell membranes important component of cell membranes produced only in animal liver cellsproduced only in animal liver cells
• naturally produced by our body naturally produced by our body
5151
Organic Molecules: ProteinsOrganic Molecules: Proteins Protein = polymer of amino acidsProtein = polymer of amino acids Combination determines structure and Combination determines structure and
functionfunction Amino acid = carbon with 3 attachmentsAmino acid = carbon with 3 attachments
Amino (NH2), carboxy (COOH) and radical Amino (NH2), carboxy (COOH) and radical group (R group)group (R group)
20 unique amino acids20 unique amino acids -R groups differ-R groups differ properties determined by -R groupproperties determined by -R group
5252
Naming of PeptidesNaming of Peptides Peptide = polymer of 2 or more amino Peptide = polymer of 2 or more amino
acidsacids Named for the number of amino acidsNamed for the number of amino acids
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
5353
Dipeptide SynthesisDipeptide Synthesis
•Dehydration synthesis creates a peptide bond that joins amino acids
5454
Protein Structure and ShapeProtein Structure and Shape Primary structure Primary structure
amino acid sequenceamino acid sequence
Secondary structureSecondary structure coiled or folded shapecoiled or folded shape hydrogen bonds between negative C=O and positive hydrogen bonds between negative C=O and positive
N-H groupsN-H groups
Tertiary structure Tertiary structure further folding and bending into globular and fibrous further folding and bending into globular and fibrous
shapesshapes
Quaternary structureQuaternary structure associations of two or more separate polypeptide associations of two or more separate polypeptide
chainschains
5656
Contain a non-amino acid moietyContain a non-amino acid moiety Hemoglobin contains complex iron Hemoglobin contains complex iron
containing ring called a containing ring called a hemeheme moiety moiety
Conjugated ProteinsConjugated Proteins
5757
Protein Conformation and Protein Conformation and DenaturationDenaturation
Conformation – unique 3-D shape crucial Conformation – unique 3-D shape crucial to functionto function ability to reversibly change their conformationability to reversibly change their conformation
• opening and closing of cell membrane poresopening and closing of cell membrane pores
DenaturationDenaturation conformational change that destroys functionconformational change that destroys function
• extreme heat, pH or saltsextreme heat, pH or salts
5858
Protein FunctionsProtein Functions StructureStructure
collagen, keratincollagen, keratin CommunicationCommunication
some hormones, cell receptorssome hormones, cell receptors Membrane TransportMembrane Transport
channels, carriers channels, carriers CatalysisCatalysis
enzymesenzymes
5959
Protein Functions 2Protein Functions 2
Recognition and protectionRecognition and protection antigens, antibodies and clotting proteinsantigens, antibodies and clotting proteins
MovementMovement molecular motor = molecules that can change molecular motor = molecules that can change
shape repeatedlyshape repeatedly Cell adhesionCell adhesion
proteins bind cells togetherproteins bind cells together
6060
EnzymesEnzymes Proteins as biological catalysts Proteins as biological catalysts
promote rapid reaction ratespromote rapid reaction rates Substrate - substance an enzyme acts Substrate - substance an enzyme acts
uponupon Naming ConventionNaming Convention
named for substrate with -ase as the suffixnamed for substrate with -ase as the suffix• amylase enzyme digests starch (amylose)amylase enzyme digests starch (amylose)
Lowers activation energy = energy needed Lowers activation energy = energy needed to get reaction startedto get reaction started enzymes facilitate molecular interactionenzymes facilitate molecular interaction
6262
Steps of an Enzyme ReactionSteps of an Enzyme Reaction Substrate approaches enzyme moleculeSubstrate approaches enzyme molecule Substrate binds to active site forming Substrate binds to active site forming
enzyme-substrate complexenzyme-substrate complex highly specifichighly specific
Enzyme breaks bonds in substrateEnzyme breaks bonds in substrate Reaction products releasedReaction products released Enzyme repeats process over and overEnzyme repeats process over and over
6464
Reusability of enzymesReusability of enzymes enzymes are unchanged by the reactionsenzymes are unchanged by the reactions
Astonishing speedAstonishing speed millions of molecules per minutemillions of molecules per minute
Temperature and pHTemperature and pH change shape of enzyme and alter its ability to change shape of enzyme and alter its ability to
bindbind enzymes vary in optimum pHenzymes vary in optimum pH
• salivary amylase works best at pH 7.0salivary amylase works best at pH 7.0• pepsin works best at pH 2.0pepsin works best at pH 2.0
temperature optimum for human enzymes = body temperature optimum for human enzymes = body temperaturetemperature
Enzymatic ActionEnzymatic Action
6565
Cofactors and CoenzymesCofactors and Coenzymes
CofactorsCofactors nonprotein partners (iron, copper, zinc, nonprotein partners (iron, copper, zinc,
magnesium or calcium ions) magnesium or calcium ions) bind to enzyme and change its shapebind to enzyme and change its shape essential to function essential to function
CoenzymesCoenzymes organic cofactors derived from water-soluble organic cofactors derived from water-soluble
vitamins (niacin, riboflavin)vitamins (niacin, riboflavin) transfer electrons between enzymestransfer electrons between enzymes
6666
Coenzyme NADCoenzyme NAD++
NADNAD++ transports electrons from one transports electrons from one metabolic pathway to anothermetabolic pathway to another
6767
Metabolic PathwaysMetabolic Pathways Chain of reactions, each catalyzed by an Chain of reactions, each catalyzed by an
enzymeenzyme A A B B C C D D A is initial reactant, B+C are intermediates A is initial reactant, B+C are intermediates
and D is the end productand D is the end product Regulation of metabolic pathways Regulation of metabolic pathways
activation or deactivation of the enzymes activation or deactivation of the enzymes cells can turn on or off pathwayscells can turn on or off pathways
6868
Organic Molecules: Organic Molecules: NucleotidesNucleotides
3 components3 components nitrogenous basenitrogenous base sugar (monosaccharide)sugar (monosaccharide) one or more phosphate groupsone or more phosphate groups
Physiological important nucleotides Physiological important nucleotides ATP = energy carrying moleculeATP = energy carrying molecule cAMP = activates metabolic pathwayscAMP = activates metabolic pathways DNA = carries genetic code DNA = carries genetic code RNA = assists with protein synthesisRNA = assists with protein synthesis
6969
ATP (Adenosine Triphosphate)ATP (Adenosine Triphosphate)
ATP contains adenine, ribose and 3 phosphate groups
7070
ATPATP Holds energy in covalent bonds Holds energy in covalent bonds
2nd and 3rd phosphate groups have high 2nd and 3rd phosphate groups have high energy bonds ~energy bonds ~
ATPases hydrolyze the 3ATPases hydrolyze the 3rdrd high energy high energy phosphate bondphosphate bond separates into ADP + Pseparates into ADP + Pii + energy + energy
PhosphorylationPhosphorylation addition of free phosphate group to another addition of free phosphate group to another
moleculemolecule
7171
Overview of ATP ProductionOverview of ATP Production
ATP consumed within 60 secondsATP consumed within 60 seconds Continually replenishedContinually replenished
7272
Other NucleotidesOther Nucleotides
Cyclic adenosine monophosphate (cAMP)Cyclic adenosine monophosphate (cAMP) formed by removal of both high energy Pformed by removal of both high energy P ii’s ’s
from ATPfrom ATP formation triggered by hormone binding to cell formation triggered by hormone binding to cell
surfacesurface cAMP becomes “second messenger” within cAMP becomes “second messenger” within
cellcell activates effects inside cellactivates effects inside cell
7373
Nucleic AcidsNucleic Acids
DNA (deoxyribonucleic acid)DNA (deoxyribonucleic acid) 100 million to 1 billion nucleotides long100 million to 1 billion nucleotides long contains genetic codecontains genetic code
• cell division, sexual reproduction, protein synthesis cell division, sexual reproduction, protein synthesis
RNA (ribonucleic acid) – 3 typesRNA (ribonucleic acid) – 3 types transfer RNA, messenger RNA, ribosomal RNAtransfer RNA, messenger RNA, ribosomal RNA 70 to 10,000 nucleotides long70 to 10,000 nucleotides long involved in protein synthesis coded for by involved in protein synthesis coded for by
DNADNA