Post on 17-Dec-2015
Impacts, IssuesImpacts, IssuesWhen Mitochondria Spin When Mitochondria Spin
Their WheelsTheir Wheels MitochondriaMitochondria are the organelles are the organelles
responsible for releasing the energy responsible for releasing the energy stored in foodsstored in foods
In In Luft’s syndromeLuft’s syndrome, the mitochondria are , the mitochondria are active in oxygen consumption, but with active in oxygen consumption, but with little ATP formation to show for itlittle ATP formation to show for it
In In Friedreich’s ataxiaFriedreich’s ataxia, too much iron in , too much iron in the mitochondria causes an accumulation the mitochondria causes an accumulation of free radicals that attack valuable of free radicals that attack valuable molecules of lifemolecules of life
The ImpactThe Impact
Proper, or improper, Proper, or improper, functioning of functioning of mitochondria is the mitochondria is the difference between difference between health and diseasehealth and disease
Producing the Universal Producing the Universal Currency of Life Currency of Life
All All energy-releasingenergy-releasing pathways: pathways: require characteristic starting require characteristic starting
materialsmaterials yield predictable products and yield predictable products and
by-products by-products produce ATP produce ATP
Photosynthesizers get energy from Photosynthesizers get energy from the sunthe sun
Animals get energy second- or Animals get energy second- or third-hand from plants or other third-hand from plants or other organismsorganisms
Regardless, Regardless, the energy is the energy is converted to the chemical bond converted to the chemical bond energy of ATPenergy of ATP
ATP Is Universal ATP Is Universal Energy SourceEnergy Source
Making ATPMaking ATP
Plants make ATP during Plants make ATP during
photosynthesisphotosynthesis
Cells of Cells of allall organisms make organisms make
ATP by breaking down ATP by breaking down
carbohydrates, fats, and proteincarbohydrates, fats, and protein
Main Types of Main Types of Energy-Releasing Energy-Releasing
Pathways Pathways Aerobic pathwaysAerobic pathways Evolved laterEvolved later Require oxygenRequire oxygen Start with Start with
glycolysis in glycolysis in cytoplasmcytoplasm
Completed in Completed in mitochondriamitochondria
Anaerobic Anaerobic pathwayspathways
Evolved firstEvolved first Don’t require Don’t require
oxygenoxygen Start with Start with
glycolysis in glycolysis in cytoplasmcytoplasm
Completed in Completed in cytoplasmcytoplasm
Overview of Aerobic Overview of Aerobic RespirationRespiration
CC66HH12120066 + 6O + 6O22 6CO6CO22 + +
6H6H2200
glucose oxygen carbon glucose oxygen carbon dioxide waterdioxide water
Overview of Aerobic Respirationcytoplasm
mitochondrion
GLYCOLYSIS
ELECTRON TRANSPORT
PHOSPHORYLATION
KrebsCycle ATP
ATP
energy input to start reactions
2 CO2
4 CO2
2
32
water
2 NADH
8 NADH
2 FADH2
2 NADH2 pyruvate
e- + H+
e- + oxygen
(2 ATP net)
glucose
TYPICAL ENERGY YIELD: 36 ATP
e-
e- + H+
e- + H+
ATP
H+
e- + H+
ATP2
Main Pathways Start Main Pathways Start with Glycolysiswith Glycolysis
GlycolysisGlycolysis occurs in cytoplasm occurs in cytoplasm Reactions are catalyzed by Reactions are catalyzed by
enzymesenzymes
GlucoseGlucose 2 Pyruvate2 Pyruvate
(six carbons) (six carbons) (three carbons)(three carbons)
Three Series of Reactions Three Series of Reactions Are Required for Aerobic Are Required for Aerobic
RespirationRespiration GlycolysisGlycolysis is the breakdown is the breakdown
of glucose to of glucose to pyruvatepyruvateSmall amountsSmall amounts of ATP are of ATP are
generatedgenerated
Three Series of Reactions Three Series of Reactions Are Required for Aerobic Are Required for Aerobic
RespirationRespiration The The Krebs cycleKrebs cycle degrades degrades
pyruvate to COpyruvate to CO22 and water; and water; NAD and FAD accept HNAD and FAD accept H++ ions ions
and electrons to be carried to and electrons to be carried to the electron transfer chainthe electron transfer chain
Small amountsSmall amounts of ATP are of ATP are generatedgenerated
Three Series of Reactions Three Series of Reactions Are Required for Aerobic Are Required for Aerobic
RespirationRespiration Electron transfer Electron transfer
phosphorylationphosphorylation processes processes the Hthe H++ ions and electrons to ions and electrons to generate lots of ATPgenerate lots of ATPOxygenOxygen is the final electron is the final electron
acceptoracceptor
The Role of CoenzymesThe Role of Coenzymes
NADNAD++ and FAD accept electrons and and FAD accept electrons and hydrogen from intermediates during hydrogen from intermediates during the first two stagesthe first two stages
When reduced, they are NADH and When reduced, they are NADH and FADHFADH22
In the third stage, these coenzymes In the third stage, these coenzymes deliver the electrons and hydrogen to deliver the electrons and hydrogen to the transfer chainthe transfer chain
Overview of Aerobic Respirationcytoplasm
mitochondrion
GLYCOLYSIS
ELECTRON TRANSPORT
PHOSPHORYLATION
KrebsCycle ATP
ATP
energy input to start reactions
2 CO2
4 CO2
2
32
water
2 NADH
8 NADH
2 FADH2
2 NADH2 pyruvate
e- + H+
e- + oxygen
(2 ATP net)
glucose
TYPICAL ENERGY YIELD: 36 ATP
e-
e- + H+
e- + H+
ATP
H+
e- + H+
ATP2
A simple sugarA simple sugar
(C(C66HH1212OO66))
Atoms held Atoms held together by together by covalent bondscovalent bonds
Glucose Glucose
Glycolysis Occurs Glycolysis Occurs in Two Stages in Two Stages
Energy-requiringEnergy-requiring steps stepsATP energy activates glucose ATP energy activates glucose
and its six-carbon derivativesand its six-carbon derivatives
Glycolysis Occurs Glycolysis Occurs in Two Stages in Two Stages
Energy-releasingEnergy-releasing steps stepsThe products of the first part The products of the first part
are split into 3-carbon are split into 3-carbon pyruvatepyruvate molecules molecules
ATPATP and and NADHNADH form form
Energy-Requiring Steps
ATP
ATP
2 ATP invested
ENERGY-REQUIRING STEPSOF GLYCOLYSIS
glucose
ADP
ADP
P
P
P
P
glucose–6–phosphate
fructose–6–phosphate
fructose–1,6–bisphosphate DHAP
Energy-Releasing Steps
ATP
PGAL PGAL
ATP
NADH NADH
ATP ATP
2 ATP produced
ENERGY-RELEASING STEPS OF GLYCOLYSIS
2 ATP produced
NAD+
Pi
NAD+
Pi
3-phosphoglycerate 3-phosphoglycerate
2-phosphoglycerate 2-phosphoglycerate
PEP PEP
ADP ADP
1,3-bisphosphoglycerate 1,3-bisphosphoglycerateP P P P
P P
P P
P P
pyruvate pyruvate
to second set of reactions
substrate-level phosphorylation
substrate-level phosphorylation
H2O H2O
ADP ADP
Glycolysis in a NutshellGlycolysis in a Nutshell Glucose is first Glucose is first phosphorylatedphosphorylated in in
energy-requiring steps, then split to energy-requiring steps, then split to form two molecules of form two molecules of PGALPGAL
Enzymes remove HEnzymes remove H++ and electrons and electrons from PGAL to change NADfrom PGAL to change NAD++ to NADH to NADH (which is used later in electron (which is used later in electron transfertransfer PGAL is converted eventually to PGAL is converted eventually to
pyruvatepyruvate By By substrate-level phosphorylationsubstrate-level phosphorylation, ,
fourfour ATP are produced ATP are produced
Substrate-level What?Substrate-level What?
Substrate-level phosphorylation Substrate-level phosphorylation means that there is a means that there is a directdirect transfer transfer of a of a phosphate groupphosphate group from the from the substrate of a reaction to some substrate of a reaction to some other molecule – in this case, ADPother molecule – in this case, ADP
SubstrateSubstrate is a reactant in a reaction is a reactant in a reaction – the substance being acted upon, – the substance being acted upon, for example, by an enzymefor example, by an enzyme
Net Energy Yield Net Energy Yield from Glycolysisfrom Glycolysis
Energy requiring stepsEnergy requiring steps:: 2 ATP invested2 ATP invested
Energy releasing stepsEnergy releasing steps::2 NADH formed 2 NADH formed 4 ATP formed4 ATP formed
Net yield is 2 ATP and 2 Net yield is 2 ATP and 2 NADHNADH
Occur in the Occur in the mitochondriamitochondria
PyruvatePyruvate is is broken down to broken down to carbon dioxidecarbon dioxide
More ATP is More ATP is formedformed
More More coenzymes are coenzymes are reducedreduced
Second-Stage Reactions Second-Stage Reactions
innermitochondrial
membrane
outermitochondrial
membrane
innercompartment
outercompartment
Two Parts of Second Two Parts of Second Stage Stage
Preparatory reactionsPreparatory reactionsPyruvate is oxidized into two-Pyruvate is oxidized into two-
carbon acetyl units and carbon acetyl units and carbon dioxidecarbon dioxide
NADNAD++ is reduced is reduced Krebs cycleKrebs cycle
The acetyl units are oxidized The acetyl units are oxidized to carbon dioxideto carbon dioxide
NADNAD+ + and FAD are reducedand FAD are reduced
pyruvate + coenzyme A + NADpyruvate + coenzyme A + NAD++
acetyl-CoA + NADH + COacetyl-CoA + NADH + CO22
One of the carbons from pyruvate is One of the carbons from pyruvate is released in COreleased in CO22
Two carbons are attached to coenzyme Two carbons are attached to coenzyme A and continue on to the Krebs cycleA and continue on to the Krebs cycle
Preparatory ReactionsPreparatory Reactions
What Is Acetyl-CoA?What Is Acetyl-CoA?
A two-carbon acetyl group A two-carbon acetyl group linked to coenzyme Alinked to coenzyme A CHCH33
C=OC=O
SS
Coenzyme Coenzyme AA
Acetyl group
NAD+
NADH
=CoAacetyl-CoA
oxaloacetate citrate
CoA
KREBS CYCLE
H2O
malate isocitrate
FAD
FADH2
fumarate
succinate
ADP + phosphate groupATP
succinyl-CoA
O O
CoANAD+
NADH
O ONAD+
NADH
-ketoglutarate
Stepped ArtStepped Art
Fig. 7-7a, p.113
H2O
H2O
The Krebs CycleThe Krebs Cycle
Overall ProductsOverall Products
Coenzyme ACoenzyme A 2 CO2 CO22
3 NADH3 NADH FADHFADH22
ATPATP
Overall Overall ReactantsReactants
Acetyl-CoAAcetyl-CoA 3 NAD3 NAD++
FADFAD ADP and PADP and Pii
Results of the Second Results of the Second StageStage
All of the carbon molecules in All of the carbon molecules in pyruvate end up in pyruvate end up in carbon carbon dioxidedioxide
Coenzymes are Coenzymes are reducedreduced (they (they pick up electrons and hydrogen)pick up electrons and hydrogen)
One molecule of ATP is formed One molecule of ATP is formed Four-carbon oxaloacetate is Four-carbon oxaloacetate is
regeneratedregenerated
Two pyruvates cross the innermitochondrial membrane.
outer mitochondrialcompartment
NADH
NADH
FADH2
ATP
2
6
2
2
KrebsCycle
6 CO2
inner mitochondrialcompartment
Eight NADH, two FADH 2, and two ATP are the payoff from the complete break-down of two pyruvates in the second-stage reactions.
The six carbon atoms from two pyruvates diffuse out of the mitochondrion, then out of the cell, in six CO
Fig. 7-6, p.112
Coenzyme Reductions Coenzyme Reductions during First Two Stagesduring First Two Stages
GlycolysisGlycolysis 2 NADH2 NADH PreparatoryPreparatory 2 NADH2 NADH
reactionsreactions Krebs cycleKrebs cycle 2 FADH 2 FADH22 + 6 NADH + 6 NADH
TotalTotal 2 FADH 2 FADH22 + 10 + 10 NADHNADH
Section 7.4Section 7.4
Third Stage of Third Stage of Aerobic Respiration – Aerobic Respiration –
The Big Energy The Big Energy PayoffPayoff
Occurs in the mitochondriaOccurs in the mitochondria Coenzymes deliver electrons Coenzymes deliver electrons
to electron transfer chainsto electron transfer chains Electron transfer sets up HElectron transfer sets up H++
ion gradientsion gradients Flow of HFlow of H++ down gradients down gradients
powers ATP formationpowers ATP formation
Electron Transfer Electron Transfer Phosphorylation Phosphorylation
Electron Electron Transfer Transfer
PhosphorylatioPhosphorylationn
Electron transfer Electron transfer
chains are embedded chains are embedded
in inner mitochondrial in inner mitochondrial
compartmentcompartment
glucose
GLYCOLYSIS
pyruvate
KREBSCYCLE
ELECTRON TRANSFERPHOSPHORYLATION
• NADH and FADH2 give up electrons that they picked up
in earlier stages to electron transfer chain
• Electrons are transferred through the chain
• The final electron acceptor is oxygen
Summary of Transfersglucose
glycolysis
e–
electrontransfer
phosphorylation
2 PGAL
2 pyruvate
2 NADH
2 CO2
ATP
ATP
2 FADH2
H+
2 NADH
6 NADH
2 FADH2
2 acetyl-CoA
ATP2 KrebsCycle
4 CO2
ATP
ATP
ATP
36
ADP + Pi
H+
H+
H+
H+
H+
H+H+
H+
Importance of OxygenImportance of Oxygen
Electron transfer Electron transfer phosphorylation phosphorylation requires the requires the presence of oxygenpresence of oxygen
Oxygen withdraws spent Oxygen withdraws spent electrons from the electron electrons from the electron transfer chain, then combines transfer chain, then combines with Hwith H++ to form to form waterwater
Summary of Energy Summary of Energy HarvestHarvest
(per molecule of glucose)(per molecule of glucose) GlycolysisGlycolysis
2 ATP formed by substrate-level 2 ATP formed by substrate-level phosphorylationphosphorylation
Krebs cycleKrebs cycle and and preparatory preparatory reactionsreactions 2 ATP formed by 2 ATP formed by substrate-level substrate-level
phosphorylationphosphorylation
Electron transfer phosphorylationElectron transfer phosphorylation 32 ATP formed32 ATP formed
What are the sources of electrons What are the sources of electrons used to generate the 32 ATP in used to generate the 32 ATP in the final stage?the final stage? 4 ATP - generated using electrons 4 ATP - generated using electrons
released during glycolysis and released during glycolysis and carried by NADHcarried by NADH
28 ATP - generated using electrons 28 ATP - generated using electrons formed during second-stage formed during second-stage reactions and carried by NADH and reactions and carried by NADH and FADHFADH22
Energy Harvest from Energy Harvest from Coenzyme ReductionsCoenzyme Reductions
Energy Harvest VariesEnergy Harvest Varies
NADH formed in cytoplasm NADH formed in cytoplasm cannot enter mitochondrioncannot enter mitochondrion
It delivers electrons to It delivers electrons to mitochondrial membranemitochondrial membrane
Membrane proteins shuttle Membrane proteins shuttle electrons to NADelectrons to NAD++ or FAD inside or FAD inside mitochondrion mitochondrion
Electrons given to FAD yield less Electrons given to FAD yield less ATP than those given to NADATP than those given to NAD++
Energy Harvest VariesEnergy Harvest Varies
Liver, kidney, heart cellsLiver, kidney, heart cells Electrons from first-stage reactions are Electrons from first-stage reactions are
delivered to NADdelivered to NAD++ in mitochondria in mitochondria Total energy harvest is 38 ATPTotal energy harvest is 38 ATP
Skeletal muscle and brain cellsSkeletal muscle and brain cells Electrons from first-stage reactions are Electrons from first-stage reactions are
delivered to FAD in mitochondriadelivered to FAD in mitochondria Total energy harvest is 36 ATPTotal energy harvest is 36 ATP
Do not use oxygenDo not use oxygen
Produce less ATP than aerobic Produce less ATP than aerobic
pathwayspathways
Two types of fermentation pathwaysTwo types of fermentation pathways
AlcoholicAlcoholic fermentation fermentation
LactateLactate fermentation fermentation
Anaerobic Pathways Anaerobic Pathways
Fermentation PathwaysFermentation Pathways
Begin with glycolysisBegin with glycolysis
Do not break glucose down Do not break glucose down
completely to carbon dioxide and completely to carbon dioxide and
waterwater
Yield only the 2 ATP from glycolysisYield only the 2 ATP from glycolysis
Steps that follow glycolysis serve Steps that follow glycolysis serve
only to regenerate NADonly to regenerate NAD++
Alcoholic Fermentation
C6H12O6
ATP
ATPNADH
2 acetaldehyde
electrons, hydrogen from NADH
2 NAD+
2
2 ADP
2 pyruvate
2
4
energy output
energy input
glycolysis
ethanol formation
2 ATP net
2 ethanol
2 H2O
2 CO2
YeastsYeasts
Single-celled fungiSingle-celled fungi Carry out alcoholic fermentationCarry out alcoholic fermentation Saccharomyces cerevisiaeSaccharomyces cerevisiae
Baker’s yeastBaker’s yeastCarbon dioxide makes bread dough Carbon dioxide makes bread dough
riserise Saccharomyces ellipsoideusSaccharomyces ellipsoideus
Used to make beer and wineUsed to make beer and wine
Lactate Fermentation
C6H12O6
ATP
ATPNADH
2 lactate
electrons, hydrogen from NADH
2 NAD+
2
2 ADP
2 pyruvate
2
4
energy output
energy input
glycolysis
lactate formation
2 ATP net
Lactate FermentationLactate Fermentation
Carried out by certain bacteriaCarried out by certain bacteria Electron transfer chain is in Electron transfer chain is in
bacterial bacterial plasma membrane plasma membrane Final electron acceptor is Final electron acceptor is
compound from environment compound from environment (such as nitrate), (such as nitrate), notnot oxygen oxygen
ATP yield is lowATP yield is low
Lactate FermentationLactate Fermentation
LactobacillusLactobacillus and some other and some other bacteria produce lactatebacteria produce lactate This produces cheeses, yogurt, This produces cheeses, yogurt,
buttermilk and other dairy productsbuttermilk and other dairy products Fermenters also are used to cure Fermenters also are used to cure
meats and in picklingmeats and in pickling Sauerkraut is an exampleSauerkraut is an example Sour taste due to Sour taste due to lactic acidlactic acid (form (form
of lactate)of lactate)
Slow-twitch v. Fast-twitch Slow-twitch v. Fast-twitch musclesmuscles
Slow-twitch musclesSlow-twitch muscles make ATP only make ATP only by aerobic respiration (no by aerobic respiration (no fermentation)fermentation) Slow-twitch muscles are for Slow-twitch muscles are for light, light,
steady, prolonged steady, prolonged activityactivity Slow-twitch muscles are Slow-twitch muscles are redred because because
they have lots of myoglobin, a pigment they have lots of myoglobin, a pigment used to store oxygenused to store oxygen
They also have They also have many mitochondriamany mitochondria
Fast-twitch MusclesFast-twitch Muscles These These palepale (lighter colored) muscles (lighter colored) muscles
have have few mitochondriafew mitochondria and and no myoglobinno myoglobin Fast-twitch muscles, which are used for Fast-twitch muscles, which are used for
immediate and intense energy demands, immediate and intense energy demands, use lactate fermentation to produce ATPuse lactate fermentation to produce ATP
It works It works quicklyquickly, but not for long, but not for long Chickens have fast-twitch breast muscles Chickens have fast-twitch breast muscles
used for quick flights (white meat)used for quick flights (white meat) Ducks fly long distances – what color is Ducks fly long distances – what color is
their breast meat?their breast meat?
Alcoholic Fermentation
C6H12O6
ATP
ATPNADH
2 acetaldehyde
electrons, hydrogen from NADH
2 NAD+
2
2 ADP
2 pyruvate
2
4
energy output
energy input
glycolysis
ethanol formation
2 ATP net
2 ethanol
2 H2O
2 CO2
Lactate Fermentation
C6H12O6
ATP
ATPNADH
2 lactate
electrons, hydrogen from NADH
2 NAD+
2
2 ADP
2 pyruvate
2
4
energy output
energy input
glycolysis
lactate formation
2 ATP net
The Fate of GlucoseThe Fate of Glucose After eating, glucose is After eating, glucose is absorbed absorbed
into the bloodinto the blood InsulinInsulin levels rise, causing greater levels rise, causing greater
uptake of glucose by cells uptake of glucose by cells GlycolysisGlycolysis will follow will follow
Excess glucose is converted into Excess glucose is converted into glycogenglycogen Glycogen is known as “animal starch,” Glycogen is known as “animal starch,”
and is the and is the main storage polysaccharide main storage polysaccharide in animalsin animals
Stored in the Stored in the musclesmuscles and the and the liverliver
Between MealsBetween Meals
When blood levels of glucose decline, When blood levels of glucose decline, pancreaspancreas
releases releases glucagonglucagon, a hormone, a hormone
Glucagon stimulates liver cells to Glucagon stimulates liver cells to convert convert
glycogen back to glucoseglycogen back to glucose and to release it to the and to release it to the
bloodblood
Glycogen levels are adequate, but can be Glycogen levels are adequate, but can be
depleted in 12 hoursdepleted in 12 hours
(Muscle cells do not release their stored (Muscle cells do not release their stored
glycogen)glycogen)
Energy ReservesEnergy Reserves
GlycogenGlycogen makes up only about makes up only about 1 percent1 percent
of the body’s energy reservesof the body’s energy reserves
ProteinsProteins make up make up 21 percent21 percent of energy of energy
reservesreserves
FatFat makes up the bulk of reserves ( makes up the bulk of reserves (78 78
percentpercent))
Energy from FatsEnergy from Fats
Most stored fats are Most stored fats are triglyceridestriglycerides in in adipose adipose
tissuetissue Triglycerides are “three-tailed” fatsTriglycerides are “three-tailed” fats
Triglycerides are broken down to Triglycerides are broken down to glycerolglycerol and and
fatty acidsfatty acids
Glycerol is converted to Glycerol is converted to PGALPGAL, an , an intermediate of intermediate of
glycolysisglycolysis
Fatty acids are broken down and converted to Fatty acids are broken down and converted to
acetyl-CoA, which enters Krebs cycleacetyl-CoA, which enters Krebs cycle
glucose
glycolysis
e–
electrontransfer
phosphorylation
2 PGAL
2 pyruvate
2 NADH
2 CO2
ATP
ATP
2 FADH2
H+
2 NADH
6 NADH
2 FADH2
2 acetyl-CoA
ATP2 KrebsCycle
4 CO2
ATP
ATP
ATP
36
ADP + Pi
H+
H+
H+
H+
H+
H+H+
H+
Energy from ProteinsEnergy from Proteins
Proteins are broken down to Proteins are broken down to amino acidsamino acids
Amino acids are broken apartAmino acids are broken apart
Amino group is removed, Amino group is removed, ammonia formsammonia forms, ,
is is converted to urea and excretedconverted to urea and excreted
Carbon backbones can enter the Krebs Carbon backbones can enter the Krebs
cycle or its preparatory reactionscycle or its preparatory reactions
Reaction SitesFOOD
fats glycogencomplex
carbohydrates proteins
simple sugars(e.g., glucose) amino acids
glucose-6-phosphate
carbon backbones
NH3
urea
ATP
(2 ATP net)
PGAL
glycolysisATP2
glycerolfatty
acids
NADH pyruvate
Acetyl-CoA
NADH CO2
KrebsCycle
NADH,FADH2
CO2
ATP
ATPATP
many ATP
fatsH+
e– + oxygen
e–
4
ATP2
When life originated, atmosphere had little When life originated, atmosphere had little
oxygenoxygen
Earliest organisms used Earliest organisms used anaerobicanaerobic pathways pathways
Later, Later, cyclic pathwaycyclic pathway (simple form) of (simple form) of
photosynthesis increased atmospheric oxygenphotosynthesis increased atmospheric oxygen
Much more efficient cells arose that used Much more efficient cells arose that used
oxygen as final acceptor in electron transferoxygen as final acceptor in electron transfer
Evolution of Metabolic Evolution of Metabolic Pathways Pathways
Processes Processes Are Are
Linked Linked
Aerobic RespirationAerobic Respiration
ReactantsReactants
Sugar Sugar
OxygenOxygen
ProductsProducts
Carbon dioxideCarbon dioxide
WaterWater
PhotosynthesisPhotosynthesis
ReactantsReactants
Carbon dioxideCarbon dioxide
WaterWater
ProductsProducts
Sugar Sugar
OxygenOxygen
Life Is System Life Is System of Prolonging Orderof Prolonging Order
Powered by energy inputs from sun, life Powered by energy inputs from sun, life
continues onward through reproductioncontinues onward through reproduction
Following instructions in DNA, energy Following instructions in DNA, energy
and materials can be organized, and materials can be organized,
generation after generationgeneration after generation
With death, molecules are released and With death, molecules are released and
may be cycled as raw material for next may be cycled as raw material for next
generation generation