UNIT 2: Chemistry of UNIT 2: Chemistry of the Human Bodythe Human Body

•CompoundsCompounds•MetabolismMetabolism•Nutrition Nutrition

WHY STUDY CHEMISTRY?WHY STUDY CHEMISTRY?

Chemistry is the ultimate (basic) cause of all Chemistry is the ultimate (basic) cause of all physiological processesphysiological processes Interactions of atoms produce chemical changes Interactions of atoms produce chemical changes

that result in compounds being broken down, built that result in compounds being broken down, built up, changed up, changed

Chemical reactions involve a transfer of energy Chemical reactions involve a transfer of energy between the compounds – makes and breaks between the compounds – makes and breaks chemical bonds that hold the atoms together… chemical bonds that hold the atoms together… and the energyand the energy

We are made of many non-living substances We are made of many non-living substances reacting with one another to give us all of reacting with one another to give us all of our characteristics of lifeour characteristics of life Metabolism, growth, reproduction, assimilation, Metabolism, growth, reproduction, assimilation,

energy use, movement etc. energy use, movement etc.

Major elements of Human Major elements of Human BodyBody

MacroelementsMacroelements Big Four: (by weight)Big Four: (by weight)

Oxygen – 65%Oxygen – 65% Carbon – 18.5%Carbon – 18.5% Hydrogen – 9.5%Hydrogen – 9.5% Nitrogen – 3.2%Nitrogen – 3.2%

96% Total of Four96% Total of Four Other ElementsOther Elements

Ca, P, K, S, Cl, Na, and Ca, P, K, S, Cl, Na, and MgMg

These elements make These elements make up 99.9% of the up 99.9% of the human bodyhuman body

Trace elements:Trace elements: Elements needed in Elements needed in

extremely small extremely small amounts but still very amounts but still very importantimportant

Co, Cu, F, I, Fe, Mn, ZnCo, Cu, F, I, Fe, Mn, Zn Too much copper (Cu) Too much copper (Cu)

Wilson Disease Wilson Disease Too little copper Too little copper

Menke’s DiseaseMenke’s Disease “ “Kinky Hair syndrome”Kinky Hair syndrome”

Too much iron (Fe) Too much iron (Fe) hemochromatosishemochromatosis

Too little iron Too little iron anemia anemia Unable to make Unable to make

hemoglobin correctlyhemoglobin correctly Too little Iodine – Goiter Too little Iodine – Goiter

Thyroid condition Thyroid condition

Basic atomic structure:Basic atomic structure: Protons - + charge; atomic numberProtons - + charge; atomic number

Found in nucleusFound in nucleus Specific for element – All atoms of the same Specific for element – All atoms of the same

element have the same # of P+element have the same # of P+ Neutrons – No electrical chargeNeutrons – No electrical charge

# of P# of P++ + # of N + # of Noo = atomic mass = atomic mass Isotopes – atoms of the same element with a Isotopes – atoms of the same element with a

different atomic massdifferent atomic mass # of neutrons differ# of neutrons differ Can be Radioactive – unstable atoms that release Can be Radioactive – unstable atoms that release

energy and particles as they decomposeenergy and particles as they decompose Electrons – (-) charged particlesElectrons – (-) charged particles

Found outside the nucleus in energy levels Found outside the nucleus in energy levels (orbitals)(orbitals)

Determine reactivity of atoms – Rule of 8Determine reactivity of atoms – Rule of 8 Ions – charged particles because of a gain or loss Ions – charged particles because of a gain or loss

of electronsof electrons

RADIOACTIVE ISOTOPESRADIOACTIVE ISOTOPES

Half-life – the amount of time it takes Half-life – the amount of time it takes for a radioactive substance to decay for a radioactive substance to decay half of its masshalf of its mass

Diagnostic Tracers: (follows specific Diagnostic Tracers: (follows specific substances through the body)substances through the body) PET Scans – Brain studiesPET Scans – Brain studies AngiographyAngiography Barium for Digestive systemBarium for Digestive system

Medical TreatmentMedical Treatment Radioactivity can kill cellsRadioactivity can kill cells Cancer treatment – radioactive Iodine Cancer treatment – radioactive Iodine

treats Thyroid Cancertreats Thyroid Cancer

RADIOACTIVE ISOTOPESRADIOACTIVE ISOTOPES

Ionizing RadiationIonizing Radiation Health problem of radioactive isotopes in Health problem of radioactive isotopes in

environmentenvironment Can cause cell death, cancer (mutations in Can cause cell death, cancer (mutations in

body cells) and birth defects (mutations in body cells) and birth defects (mutations in reproductive cellsreproductive cells

Mutations – changes in DNA (genes)Mutations – changes in DNA (genes) Free radicals – ions formed from radiation that Free radicals – ions formed from radiation that

interfere with metabolisminterfere with metabolism Anti-oxidants – certain substances in food that Anti-oxidants – certain substances in food that

help prevent the formation of free radicalshelp prevent the formation of free radicals Nuclear Waste, Medical WastesNuclear Waste, Medical Wastes Always exposed to radiation – certain Always exposed to radiation – certain

levels are considered safelevels are considered safe

MetabolismMetabolism Metabolism – the sum of all chemical Metabolism – the sum of all chemical

reactions in the bodyreactions in the body Reactants interact (react) with one Reactants interact (react) with one

another to form productsanother to form products Anabolism – reactions that form larger, Anabolism – reactions that form larger,

more complex moleculesmore complex molecules Requires an input of energy (endergonic)Requires an input of energy (endergonic) Dehydration synthesis – reactions that build Dehydration synthesis – reactions that build

large organic molecules; form waterlarge organic molecules; form water Catabolism – reactions that break down Catabolism – reactions that break down

larger molecules into simpler formslarger molecules into simpler forms release of energy (exergonic)release of energy (exergonic) Hydrolysis – break down of large organic Hydrolysis – break down of large organic

compounds into basic units (monomers); split compounds into basic units (monomers); split waterwater

Anabolism + Catabolism = MetabolismAnabolism + Catabolism = Metabolism Each reaction requires a specific enzyme Each reaction requires a specific enzyme

to happento happen

EnzymesEnzymes

Enzymes – biological catalystsEnzymes – biological catalysts Speed the rate of reactions by lowering the Speed the rate of reactions by lowering the

activation energyactivation energy Activation energy – energy needed for a chemical Activation energy – energy needed for a chemical

reaction to happenreaction to happen Enzymes are proteinsEnzymes are proteins

Lock and Key ModelLock and Key Model Each enzyme has a definite, specific shape (lock)Each enzyme has a definite, specific shape (lock) Substrate – reactants involved in the enzymatic Substrate – reactants involved in the enzymatic

reaction (key)reaction (key) Substrate must fit into active site of enzyme for Substrate must fit into active site of enzyme for

reaction to occurreaction to occur One enzyme One enzyme one specific reaction one specific reaction

Enzymes are not changed during the reaction Enzymes are not changed during the reaction Can be recycledCan be recycled

EnzymesEnzymes

Coenzymes – smaller organic molecules that Coenzymes – smaller organic molecules that are needed for a proper fit of an enzyme to are needed for a proper fit of an enzyme to substratesubstrate VitaminsVitamins

Cofactors – ions needed for proper fit of Cofactors – ions needed for proper fit of enzyme/substrateenzyme/substrate MineralsMinerals

Denaturation – the change of a protein’s shapeDenaturation – the change of a protein’s shape Change the shape, change (usually ruin) the functionChange the shape, change (usually ruin) the function Once it happens, usually will not return to normalOnce it happens, usually will not return to normal High temperatures – feverHigh temperatures – fever Wrong pH – hydrogen ions, hydroxide ions interfere Wrong pH – hydrogen ions, hydroxide ions interfere

with shape and substrate/enzyme interactionwith shape and substrate/enzyme interaction Salt concentration – ions interfereSalt concentration – ions interfere

Inorganic substancesInorganic substances

Do not contain CarbonDo not contain Carbon COCO22 is sometimes considered is sometimes considered

exception (our text lists as inorganic)exception (our text lists as inorganic) Now most scientists list this as organic Now most scientists list this as organic

because it is the ultimate source of all because it is the ultimate source of all organic compounds organic compounds

Plants turn COPlants turn CO22 into organic compounds into organic compounds by photosynthesis by photosynthesis passed to all other passed to all other organisms through consumptionorganisms through consumption

Know significance of water, oxygen, Know significance of water, oxygen, carbon dioxide and saltscarbon dioxide and salts

Inorganic substancesInorganic substances Water (HWater (H22O)O)

Most abundant substance in body – approx 2/3 of Most abundant substance in body – approx 2/3 of weightweight

Highly polar moleculeHighly polar molecule Partial charges on opposite ends of moleculePartial charges on opposite ends of molecule Acts like a molecular magnetActs like a molecular magnet Chief reason why water is so importantChief reason why water is so important

High Heat Capacity – takes a lot of energy to High Heat Capacity – takes a lot of energy to change the temperature of waterchange the temperature of water

Helps maintain a stable body temperatureHelps maintain a stable body temperature High Heat of Vaporization – takes a lot of heat High Heat of Vaporization – takes a lot of heat

energy to turn liquid water into water vaporenergy to turn liquid water into water vapor Evaporative cooling – cooling by evaporating waterEvaporative cooling – cooling by evaporating water Sweating – uses body heat to evaporate water; Sweating – uses body heat to evaporate water;

body loses heat energy and coolsbody loses heat energy and cools Expands when it freezes (negative)Expands when it freezes (negative)

Kills cells when cellular fluid freezesKills cells when cellular fluid freezes FrostbiteFrostbite Necrosis – tissue death; black; loss of structureNecrosis – tissue death; black; loss of structure Infection; gang greenInfection; gang green

Inorganic substancesInorganic substances Universal Solvent – dissolves many Universal Solvent – dissolves many

substances (polar and ionic compounds)substances (polar and ionic compounds) Dissociation – the pulling apart of ionic compounds Dissociation – the pulling apart of ionic compounds

by waterby water NaCl (salt) NaCl (salt) Na Na++ + Cl + Cl-- Forms electrolytes - ions necessary for metabolismForms electrolytes - ions necessary for metabolism

pH – scale to measure the acidity of a substancepH – scale to measure the acidity of a substance 0 – 140 – 14 Each step is 10X differenceEach step is 10X difference Acids – substances with more H+ ions than OH- ionsAcids – substances with more H+ ions than OH- ions

Below 7Below 7 Lower the number; stronger the acidLower the number; stronger the acid

Bases – substances with more OH- ions than H+ ionsBases – substances with more OH- ions than H+ ions Above 7Above 7 Higher the number, stronger the baseHigher the number, stronger the base

Neutral substances - H+ = OH-Neutral substances - H+ = OH- pH 7pH 7 Dissociation of water (HDissociation of water (H22O O H+ + OH-) H+ + OH-)

Inorganic substancesInorganic substances pH (continued)pH (continued)

Neutralizaiton reaction – mixing an acid and a base to Neutralizaiton reaction – mixing an acid and a base to form a neutral solutionform a neutral solution

Forms salt and waterForms salt and water HCl (A) + NaOH (B) HCl (A) + NaOH (B) NaCl (S) + HOH (W) NaCl (S) + HOH (W)

Buffers – substances that regulate the pH of a solution Buffers – substances that regulate the pH of a solution by absorbing or releasing H+ ionsby absorbing or releasing H+ ions

Example of Buffering SystemExample of Buffering System Blood – Normal pH 7.4 - 7.7Blood – Normal pH 7.4 - 7.7

Alkalosis – pH too highAlkalosis – pH too high Acidosis – pH too lowAcidosis – pH too low

Uses bicarbonate ion (HCOUses bicarbonate ion (HCO33--) as buffer) as buffer

COCO22 combines with water to form carbonic acid (H combines with water to form carbonic acid (H22COCO33)) Carbonic acid dissociates into bicarbonate ions (HCOCarbonic acid dissociates into bicarbonate ions (HCO33

--) ) and hydrogen ions (Hand hydrogen ions (H++))

HH22COCO33 HCO HCO3-3- + H + H++

If pH is too low, reaction proceeds to left; forms If pH is too low, reaction proceeds to left; forms carbonic acid, lowers amount of Hcarbonic acid, lowers amount of H++ ions; raises pH ions; raises pH

If pH is too high, reaction proceeds to right; forms If pH is too high, reaction proceeds to right; forms bicarbonate ion; increase Hbicarbonate ion; increase H++ ions, lowers pH ions, lowers pH

Inorganic substancesInorganic substances Oxygen (OOxygen (O22))

Used to release energy stored in foodUsed to release energy stored in food Taken into body by respiratory systemTaken into body by respiratory system

Diffuses into blood at alveoli in lungs – microscopic Diffuses into blood at alveoli in lungs – microscopic air sacs at the end of the bronchial treeair sacs at the end of the bronchial tree

21% of atmosphere21% of atmosphere Final electron acceptor in aerobic respirationFinal electron acceptor in aerobic respiration

Glycolysis – Glucose Glycolysis – Glucose pyruvic acid pyruvic acid Happens in cytoplasmHappens in cytoplasm Produces 2 ATP; NADHProduces 2 ATP; NADH

Kreb’s (Citric Acid) CycleKreb’s (Citric Acid) Cycle Happens in mitochondriaHappens in mitochondria Produces 2 ATP; NADH and FADHProduces 2 ATP; NADH and FADH

Electron Transport ChainElectron Transport Chain Happens in mitochondriaHappens in mitochondria NADH and FADH produced in glycolysis and Kreb’s NADH and FADH produced in glycolysis and Kreb’s

Cycle travel to e- transport chainCycle travel to e- transport chain Electrons are passed down the chain and energy is Electrons are passed down the chain and energy is

used (transferred) to make ATP – 34 ATPused (transferred) to make ATP – 34 ATP

Inorganic substancesInorganic substances

Without Oxygen – anaerobic respirationWithout Oxygen – anaerobic respiration Lactic Acid fermentationLactic Acid fermentation Only 2 ATP’s produced – not enough for long term useOnly 2 ATP’s produced – not enough for long term use Lactic acid produced as by-product; interferes with proper Lactic acid produced as by-product; interferes with proper

muscle contractions (cramps and fatigue)muscle contractions (cramps and fatigue) Oxygen Debt – oxygen needed to replenish ATP supply and Oxygen Debt – oxygen needed to replenish ATP supply and

get rid of lactic acid build-up in musclesget rid of lactic acid build-up in muscles Carbon DioxideCarbon Dioxide

Some consider it to be organicSome consider it to be organic Ultimate (original) source of carbon for all organic Ultimate (original) source of carbon for all organic

compoundscompounds Waste product of cellular metabolismWaste product of cellular metabolism

Produced when glucose is broken down during aerobic Produced when glucose is broken down during aerobic respirationrespiration

Lowers pH by forming carbonic acidLowers pH by forming carbonic acid Buffered by bicarbonate ions (see pH notes)Buffered by bicarbonate ions (see pH notes)

Salts – metal ionically bonded to nonmetalSalts – metal ionically bonded to nonmetal Dissociates in waterDissociates in water Forms ions (electrolytes) necessary for metabolismForms ions (electrolytes) necessary for metabolism

Organic compoundsOrganic compounds

Compounds that contain carbon, Compounds that contain carbon, hydrogen and usually oxygenhydrogen and usually oxygen

Accounts for most of our solid partAccounts for most of our solid part Four main groups: carbohydrates, Four main groups: carbohydrates,

lipids, proteins, nucleic acidslipids, proteins, nucleic acids Basic Information – Basic Information –

Make up most of the solid parts of our Make up most of the solid parts of our bodiesbodies

All are composed of repeating basic units All are composed of repeating basic units called monomerscalled monomers

Put together by dehydration synthesis Put together by dehydration synthesis reactions: covalently bond by removing reactions: covalently bond by removing water molecule (anabolic)water molecule (anabolic)

Broken down by Hydrolysis reactions: Broken down by Hydrolysis reactions: break bonds by splitting water (catabolic)break bonds by splitting water (catabolic)

Organic compoundsOrganic compounds

CarbohydratesCarbohydrates Contain C, H, and O (H:O is 2:1) Contain C, H, and O (H:O is 2:1) carbo (carbon) - carbo (carbon) -

hydrate(water)hydrate(water) Monomer – monosaccharides (glucose, fructose, Monomer – monosaccharides (glucose, fructose,

galactose)galactose) Glucose is main source of energy for cellsGlucose is main source of energy for cells Broken down by aerobic respiration to transfer energy stored Broken down by aerobic respiration to transfer energy stored

in glucose to ATPin glucose to ATP Blood sugar level is conc. of glucose in bloodBlood sugar level is conc. of glucose in blood Sucrose – disaccharide; table sugar; two monosaccharides Sucrose – disaccharide; table sugar; two monosaccharides

bonded togetherbonded together Polysaccharide – long chains of monomers (glucose) Polysaccharide – long chains of monomers (glucose)

bonded togetherbonded together Glycogen – stores energy for in between mealsGlycogen – stores energy for in between meals

Stored in liver and muscle tissueStored in liver and muscle tissue Starch – plant long term energy storageStarch – plant long term energy storage

Found in pasta, potatoes, grain (breads)Found in pasta, potatoes, grain (breads) Cellulose – makes up cell wallsCellulose – makes up cell walls

Not able to be digestedNot able to be digested Helps things go through the digestive tract – FiberHelps things go through the digestive tract – Fiber

Main Use – immediate energy and short term energy Main Use – immediate energy and short term energy storagestorage

If not all the glycogen is used up, then the body stores it in If not all the glycogen is used up, then the body stores it in the more stable form of fat.the more stable form of fat.

Organic compoundsOrganic compounds

Lipids – fats; triglyceridesLipids – fats; triglycerides Elements C, H, and O (lot more C and H than O) Elements C, H, and O (lot more C and H than O) long long

chains of H and C (hydrocarbons)chains of H and C (hydrocarbons) Monomer is glycerol + 3 fatty acid chainsMonomer is glycerol + 3 fatty acid chains

Energy is stored in C-H bonds of fatty acidsEnergy is stored in C-H bonds of fatty acids Saturated fats – no double bonds between C in fatty acid Saturated fats – no double bonds between C in fatty acid

chains; max. amt. of Hchains; max. amt. of H Linked to vascular disease – atherosclerosisLinked to vascular disease – atherosclerosis Animal fats, coconut and palm oilsAnimal fats, coconut and palm oils

Unsaturated fats – double bonds between C in fatty acid Unsaturated fats – double bonds between C in fatty acid chains; missing H’schains; missing H’s

HealthierHealthier Plant oils – peanut and corn oilsPlant oils – peanut and corn oils

Main function – long term energy storageMain function – long term energy storage Can be broken down for energy if not enough calories from Can be broken down for energy if not enough calories from

carbs are taken incarbs are taken in Actually stores more energy than carbs per unit of weightActually stores more energy than carbs per unit of weight

Steroids – lipids with four rings of hydrocarbonsSteroids – lipids with four rings of hydrocarbons Cholesterol – fat that is produced by liver and taken in by Cholesterol – fat that is produced by liver and taken in by

diet; too much can clog arteries diet; too much can clog arteries heart disease heart disease Testosterone, estrogen – sex hormonesTestosterone, estrogen – sex hormones

Stimulates changes that occur during pubertyStimulates changes that occur during puberty

Organic compoundsOrganic compounds

ProteinsProteins Elements C, H, O and N (sometimes S)Elements C, H, O and N (sometimes S) Monomer – amino acidsMonomer – amino acids

Central Carbon, amino group (NH2), carboxyl group Central Carbon, amino group (NH2), carboxyl group (COOH) and “R” group(COOH) and “R” group

““R” Group only thing that differs between amino acidsR” Group only thing that differs between amino acids Linked together by peptide bondsLinked together by peptide bonds Order of amino acids determine shape, function and Order of amino acids determine shape, function and

type of proteintype of protein Polymer – polypeptide; long chains of amino acidsPolymer – polypeptide; long chains of amino acids

Hemoglobin – protein found on red blood cells that Hemoglobin – protein found on red blood cells that is necessary to carry oxygen through the bloodis necessary to carry oxygen through the blood

Insulin – protein that acts as a hormone to tell liver Insulin – protein that acts as a hormone to tell liver to synthesize glycogento synthesize glycogen

Functions – most varied in biological systemsFunctions – most varied in biological systems Structural – actin and myosin in muscle tissueStructural – actin and myosin in muscle tissue Enzymes – regulate metabolismEnzymes – regulate metabolism

See enzyme notes See enzyme notes

Organic compoundsOrganic compounds

Nucleic Acids (genetic information)Nucleic Acids (genetic information) Elements C, H, O, N and PElements C, H, O, N and P Monomer: nucleotideMonomer: nucleotide

Consists of 5 C sugar, phosphate group and Consists of 5 C sugar, phosphate group and nitrogenous basenitrogenous base

Nitrogen bases: Adenine, Thymine (DNA only), Nitrogen bases: Adenine, Thymine (DNA only), Uracil (RNA only), Guanine, CytosineUracil (RNA only), Guanine, Cytosine

Polymers – chains of nucleic acids; DNA and RNAPolymers – chains of nucleic acids; DNA and RNA Order of the bases are essential for functionOrder of the bases are essential for function DNA (deoxyribonucleic acid): double stranded; DNA (deoxyribonucleic acid): double stranded;

deoxyribose sugar; bases are A, T, C and G; master deoxyribose sugar; bases are A, T, C and G; master copy; found in nucleuscopy; found in nucleus

RNA (ribonucleic acid): single stranded; ribose is RNA (ribonucleic acid): single stranded; ribose is sugar; bases A, U, C and G; copy of DNA; can sugar; bases A, U, C and G; copy of DNA; can travel to cytoplasmtravel to cytoplasm

ATP (adenosine triphosphate) – energy molecules ATP (adenosine triphosphate) – energy molecules used by cellsused by cells

Also a nucleic acidAlso a nucleic acid Adenosine (adenine + ribose); 3 phosphate groupsAdenosine (adenine + ribose); 3 phosphate groups

Energy is stored between phosphate groups Energy is stored between phosphate groups Break bonds to release energy, form bonds to store Break bonds to release energy, form bonds to store

energyenergy

Organic compoundsOrganic compounds

From Gene to Protein:From Gene to Protein: Gene – a segment of DNA that codes for the production of Gene – a segment of DNA that codes for the production of

a specific proteina specific protein Controls cell activities by what proteins (enzymes) they code Controls cell activities by what proteins (enzymes) they code

forfor Order of bases determine what amino acids sequence is used Order of bases determine what amino acids sequence is used

in protein in protein function of individual proteins function of individual proteins Transcription – copying the DNA gene to a strand of mRNATranscription – copying the DNA gene to a strand of mRNA Translation – ribosomes assemble amino acids into the Translation – ribosomes assemble amino acids into the

correct sequencecorrect sequence Knows the sequence by the mRNA codeKnows the sequence by the mRNA code

Problems – Mutations Problems – Mutations Def: changes in the DNA sequenceDef: changes in the DNA sequence Change DNA sequence Change DNA sequence change order of amino acids in change order of amino acids in

protein protein change shape of protein change shape of protein destroy function destroy function Sickle Cell anemia – point mutationSickle Cell anemia – point mutation

Changes hemoglobin molecules; one amino acid is Changes hemoglobin molecules; one amino acid is different in polypeptide; inaffective at carrying oxygendifferent in polypeptide; inaffective at carrying oxygen

Frameshift mutations – changes entire amino acid sequence Frameshift mutations – changes entire amino acid sequence after mutationafter mutation

Cancer – mutations in genes that control cell cycleCancer – mutations in genes that control cell cycle Oncogenes – turned on to make cells divide too quicklyOncogenes – turned on to make cells divide too quickly Tumor Suppressor genes – turned off to make cells divide Tumor Suppressor genes – turned off to make cells divide

too quicklytoo quickly Tumor – mass of nonfunctional cells that starve Tumor – mass of nonfunctional cells that starve

surrounding good cellssurrounding good cells

NutritionNutrition Def: how we obtain and use the raw materials necessary Def: how we obtain and use the raw materials necessary

for proper functioning of the human body through dietfor proper functioning of the human body through diet Organic compounds must be broken down into simplest Organic compounds must be broken down into simplest

form before taken into the bodyform before taken into the body Digestion makes this happenDigestion makes this happen Not in the body until absorbed across barrier into Not in the body until absorbed across barrier into

bloodstream – usually in small intestinesbloodstream – usually in small intestines Carbohydrate utilization Carbohydrate utilization

Absorbed as monosaccharides; glucose, fructose and Absorbed as monosaccharides; glucose, fructose and galactosegalactose

Fructose and galactose are usually turned into glucose by liverFructose and galactose are usually turned into glucose by liver Glucose is used by cells for energy (ATP synthesis)Glucose is used by cells for energy (ATP synthesis) Not all glucose is used at once – liver stores some as Not all glucose is used at once – liver stores some as

glycogenglycogen Glycogen is broken down for a continuous supply of glucose Glycogen is broken down for a continuous supply of glucose

in bloodin blood If not all the glycogen is used, body turns it into fat and stores itIf not all the glycogen is used, body turns it into fat and stores it If there is not enough glycogen between meals, body will burn If there is not enough glycogen between meals, body will burn

fat and use it for energyfat and use it for energy RequirementsRequirements

Minimum: 125 – 175 grams per dayMinimum: 125 – 175 grams per day Normal: 200 – 300 grams per dayNormal: 200 – 300 grams per day

NutritionNutrition

Lipid metabolismLipid metabolism Must be broken down into glycerol and fatty acid Must be broken down into glycerol and fatty acid

chains before entering bodychains before entering body Can be used for structure (cell membrane – Can be used for structure (cell membrane –

phospholipids) or long term energy storagephospholipids) or long term energy storage Cholesterol is used in cell membranesCholesterol is used in cell membranes Steroids are used as hormonesSteroids are used as hormones

Beta Oxidation – change fatty acid chains into Beta Oxidation – change fatty acid chains into compounds that can be utilized by cell respiration compounds that can be utilized by cell respiration for energyfor energy

Acety Coenzyme A Acety Coenzyme A Ketone bodies form from other parts – acetoneKetone bodies form from other parts – acetone

Can make breath and urine smell fruity – sign of Can make breath and urine smell fruity – sign of starvationstarvation

Can also be changed into acetyl coA for energyCan also be changed into acetyl coA for energy Essential Fatty acids – those that cannot be Essential Fatty acids – those that cannot be

produced by body; must be taken in through dietproduced by body; must be taken in through diet Linolenic acid; arachidonic acidLinolenic acid; arachidonic acid

Should not exceed 30% of caloric intakeShould not exceed 30% of caloric intake

NutritionNutrition

Protein MetabolismProtein Metabolism Broken down into amino acids before Broken down into amino acids before

absorbedabsorbed Reassembled into proteins necessary for Reassembled into proteins necessary for

the bodythe body Mainly structural proteins, enzymes, clotting Mainly structural proteins, enzymes, clotting

factors, cell identification (antigens), antibodies, factors, cell identification (antigens), antibodies, hormones, regulate water balancehormones, regulate water balance

Can be used as an energy source if neededCan be used as an energy source if needed Essential amino acids – 8 amino acids that Essential amino acids – 8 amino acids that

the body cannot producethe body cannot produce Isoleucine, leucine, lysine, methionine, Isoleucine, leucine, lysine, methionine,

phenyalanine, threonine, tryptophan, valine phenyalanine, threonine, tryptophan, valine PKU – genetic disorder that does not allow the PKU – genetic disorder that does not allow the

body to metabolize phenylalaninebody to metabolize phenylalanine Accumulates and can cause mental retardationAccumulates and can cause mental retardation Warnings on food products (artificial sweeteners)Warnings on food products (artificial sweeteners)

Vegetarians must be careful because plants do Vegetarians must be careful because plants do not always contain complete proteinsnot always contain complete proteins

NutritionNutrition Using protein for energyUsing protein for energy

When not enough carbohydrates are present, body will When not enough carbohydrates are present, body will break down amino acids for energybreak down amino acids for energy

Deamination – removing amino groups from amino acidsDeamination – removing amino groups from amino acids Contains NitrogenContains Nitrogen Amino groups converted into urea Amino groups converted into urea removed in urine removed in urine

Energy Values of FoodEnergy Values of Food Calories – units of heat (energy)Calories – units of heat (energy)

Physics: 1 calorie = amt of heat needed to raise the Physics: 1 calorie = amt of heat needed to raise the temperature of 1 gram of water by 1temperature of 1 gram of water by 1oo Celsius Celsius

Food: 1 calorie = 1000 physics calories (kilocalorie)Food: 1 calorie = 1000 physics calories (kilocalorie) Determined using a bomb calorimeterDetermined using a bomb calorimeter BMR – basal metabolic rateBMR – basal metabolic rate

Amount of energy needed for basic functioning of body; Amount of energy needed for basic functioning of body; measured when a person is awake, at rest after a night of measured when a person is awake, at rest after a night of fastingfasting

Energy Balance – compares how much energy is taken Energy Balance – compares how much energy is taken in to how much energy is usedin to how much energy is used

Excess energy is stored as fat in adipose tissueExcess energy is stored as fat in adipose tissue Obesity – over 20% overweightObesity – over 20% overweight See Body Mass Index – Clinical Appliation 18.1 P. 731See Body Mass Index – Clinical Appliation 18.1 P. 731

NutritionNutrition Vitamins – small organic compounds Vitamins – small organic compounds

necessary for normal metabolic processesnecessary for normal metabolic processes Can’t be made by body Can’t be made by body must be supplied by must be supplied by

food we eatfood we eat Fat Soluble Vitamins – A, D, E, KFat Soluble Vitamins – A, D, E, K

Disorders: night blindness, ricketsDisorders: night blindness, rickets Water soluble vitamins – B (Thiamine B1, Water soluble vitamins – B (Thiamine B1,

Riboflavin B2, Niacin, B6, Pantothenic acid, Riboflavin B2, Niacin, B6, Pantothenic acid, Cyanocobalamin B12, Folic Acid, Biotin), C Cyanocobalamin B12, Folic Acid, Biotin), C (ascorbic acid)(ascorbic acid)

Disorders - scurvyDisorders - scurvy Minerals – inorganic elements that are Minerals – inorganic elements that are

essential in human metabolismessential in human metabolism Calcium and phosphorus make up 75%Calcium and phosphorus make up 75% About 4% of body weight; concentrated in teeth About 4% of body weight; concentrated in teeth

and bonesand bones Ca, P, K, S, Na, Cl, Ca, P, K, S, Na, Cl, Trace elements: Fe, Mn, Cu, I, Co, Zn, F, Cr Trace elements: Fe, Mn, Cu, I, Co, Zn, F, Cr

Healthy EatingHealthy Eating

Needs to provide sufficient energy, essential Needs to provide sufficient energy, essential fatty acids, essential amino acids, vitamins fatty acids, essential amino acids, vitamins and mineralsand minerals

RDA – recommended daily allowancesRDA – recommended daily allowances Set up by nutritionists to help make sure people are Set up by nutritionists to help make sure people are

getting a balanced dietgetting a balanced diet Found on food labelsFound on food labels

Food Pyramid – placing foods into groupsFood Pyramid – placing foods into groups 1950’s – 4 food groups; 1940’s – 8 food groups; 1950’s – 4 food groups; 1940’s – 8 food groups;

1920’s – had group devoted to sweets1920’s – had group devoted to sweets See Figure 18.16 – P. 746 (1992)See Figure 18.16 – P. 746 (1992) Look on labels to help determine how healthy foods Look on labels to help determine how healthy foods

areare Most abundant ingredient listed firstMost abundant ingredient listed first Focus on caloriesFocus on calories

Healthy EatingHealthy Eating DisordersDisorders

Malnutrition – lack of essential nutrients or failure to use Malnutrition – lack of essential nutrients or failure to use themthem

Can be because of not enough or too muchCan be because of not enough or too much Can be genetic; still present with healthy dietCan be genetic; still present with healthy diet

Starvation – no food intakeStarvation – no food intake 50 – 70 day survival rate for healthy humans50 – 70 day survival rate for healthy humans Body begins to digest itselfBody begins to digest itself 1 day 1 day sugars and starches are gone sugars and starches are gone Next uses fat, then protein (muscle tissue)Next uses fat, then protein (muscle tissue) Metabolism slows Metabolism slows

Marasmus – lack of nutrients; look like living skeletonMarasmus – lack of nutrients; look like living skeleton Kwashiorkor – “the evil spirit which infects the first child Kwashiorkor – “the evil spirit which infects the first child

when the second one is born”when the second one is born” Common after baby is weaned from breast milkCommon after baby is weaned from breast milk Ascites – belly swells from fluid build upAscites – belly swells from fluid build up

Anorexia Nervosa – self-imposed starvationAnorexia Nervosa – self-imposed starvation 1 out of 250 adolescents 1 out of 250 adolescents 95% female 95% female Ritualized eating behavior, brittle hair, irregular heart rate, Ritualized eating behavior, brittle hair, irregular heart rate,

constipation, chiliness, low blood pressure, lanugoconstipation, chiliness, low blood pressure, lanugo 15% to 21% death rate15% to 21% death rate

Bulimia – binging and purgingBulimia – binging and purging Tooth decay, marks on back of hands, raw throat, stomach Tooth decay, marks on back of hands, raw throat, stomach

ulcersulcers Tough to break cycle even with counselingTough to break cycle even with counseling