cell energy photosynthesis and respiration. how do cells store energy? adenosine triphosphate (atp)...
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Cell EnergyCell Energy
Photosynthesis and RespirationPhotosynthesis and Respiration
How do Cells Store Energy?How do Cells Store Energy?
Adenosine Triphosphate (ATP) – the molecule where the energy is stored for cell processes.
NADP+ and NADPH- carrier molecules that carry high energy electrons for reactions in the cell.
ATP ModelATP Model
Adenine Ribose 3 Phosphate groups
ATP- ADP CycleATP- ADP Cycle When ATP loses a phosphate group it
releases energy and becomes ADP (Adenosine Diphosphate).
ATP vs. ADP ATP vs. ADP compared to a batterycompared to a battery
ADP ATP
Adenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)
Partiallychargedbattery
Fullychargedbattery
ATP-ADP CycleATP-ADP Cycle
Energy is added with a
phosphate to ADP
Energy is released with a
phosphate
ATP is formed
ADP is formed
PhotosynthesisPhotosynthesis
Photosynthesis – plants trap the sun’s energy and store it in molecules of glucose. Process of using sun’s energy to make food for the
plant.
Photosynthesis FormulaPhotosynthesis Formula
Process of PhotosynthesisProcess of Photosynthesis
sunlightsunlight
Carbon Dioxide + Water glucose + oxygen Carbon Dioxide + Water glucose + oxygen
chlorophyllchlorophyll
ReactantsReactants Products Products
Photosynthesis takes place in leaves Photosynthesis takes place in leaves (primarily)…(primarily)…
Leaves are the major sites of photosynthesis (although any green vegetation can do so).
Within cells of the leaf, photosynthesis Within cells of the leaf, photosynthesis takes place in the CHLOROPLASTS…takes place in the CHLOROPLASTS…
Elodea cells with small, circular chloroplasts
Thought it didn’t go any smaller?Thought it didn’t go any smaller?
Within those crazy chloroplasts…Within those crazy chloroplasts…
Thylakoids: sacs containing chlorophyll (pancake)
Grana: stack of thylakoid disks (stack of pancakes)
Stroma: the region outside the grana. (syrup)
So where’s the juice?So where’s the juice? Nature of Sunlight—
Light = electromagnetic energy (radiation), travels in rhythmic waves ( wavelengths)
Entire range = electromagnetic spectrum Visible light drives photosynthesis
Photons & PigmentsPhotons & Pigments
Light behaves like individual particles called photons
Light can be absorbed, reflected, transmitted Things that absorb —called pigments Photosynthesis pigments:
chlorophyll a (blue-green) chlorophyll b (yellow-green) carotenoids (yellow-orange)
Two Steps of Two Steps of Photosynthesis:Photosynthesis:
1.1. Light Dependent ReactionLight Dependent Reaction
2.2. Light Independent Reaction Light Independent Reaction (also called Calvin Cycle or (also called Calvin Cycle or Dark Cycle).Dark Cycle).
Light-Dependent Reactions- 1Light-Dependent Reactions- 1stst step step of Photosynthesisof Photosynthesis
Takes place in thylakoid membranes (pancakes).
Requires light energy Sunlight and water enter the grana as
reactants. Oxygen is produced. ATP and NADPH go to the Calvin
Cycle.
Sunlight- reactant
Carbon Dioxide- reactant
Oxygen- product Glucose/Sugar- product
Light-Dependent Reactions
CalvinCycle
NADP+
ADP + P
ATP
NADPH
Water- reactant
22ndnd Step: Light-Independent Step: Light-Independent ReactionsReactions
(Calvin Cycle/Dark Cycle)(Calvin Cycle/Dark Cycle) No light requiredNo light required Takes place in the stroma (syrup)Takes place in the stroma (syrup) Carbon dioxide enters as reactant.Carbon dioxide enters as reactant. Glucose is produced.Glucose is produced. For every 6 molecules of COFor every 6 molecules of CO22, only one , only one
molecule of glucose is formed.molecule of glucose is formed. ADP and NADP+ go to Light Dependent ADP and NADP+ go to Light Dependent
Step.Step.
Sunlight- reactant
Carbon Dioxide- reactant
Oxygen- product Glucose/Sugar- product
Light-Dependent Reactions
CalvinCycle
NADP+
ADP + P
ATP
NADPH
Water- reactant
Cell RespirationCell Respiration
The process where food molecules are broken down The process where food molecules are broken down in the presence of oxygen to release energy.in the presence of oxygen to release energy.
Takes place in mitochondria and cytoplasm.Takes place in mitochondria and cytoplasm. This process may be:This process may be:
Aerobic ( in the presence of oxygen)Aerobic ( in the presence of oxygen) Anaerobic (without oxygen)Anaerobic (without oxygen)
The equation for cellular respiration is:The equation for cellular respiration is:
6O6O22 + C + C66HH1212OO66 6CO6CO22 + 6H + 6H22O + EnergyO + Energy
3 Main Stages of Cell Respiration3 Main Stages of Cell Respiration
1.1. GlycolysisGlycolysis
2.2. Krebs CycleKrebs Cycle
3.3. Electron Transport ChainElectron Transport Chain
GlycolysisGlycolysis
Occurs in cytoplasm Occurs in cytoplasm One molecule of glucose is broken in half, One molecule of glucose is broken in half,
producing pyruvic acids.producing pyruvic acids. 2 molecules of ATP are produced2 molecules of ATP are produced Does not require oxygen (anaerobic)Does not require oxygen (anaerobic)
2 Pyruvic acid
After GlycolysisAfter Glycolysis
If oxygen is present ( aerobic) the second stage If oxygen is present ( aerobic) the second stage is the Krebs cycle.is the Krebs cycle.
If oxygen is not present, glycolysis is followed If oxygen is not present, glycolysis is followed by Fermentation.by Fermentation.
Krebs Cycle Krebs Cycle (also called citric acid cycle)(also called citric acid cycle)
At end of glycolysis about 90% of the chemical At end of glycolysis about 90% of the chemical energy from glucose is still unused. Oxygen needed energy from glucose is still unused. Oxygen needed to extract that energy.to extract that energy.
Aerobic (requires oxygen)Aerobic (requires oxygen) Occurs in mitochondria.Occurs in mitochondria. Pyruvic acid is broken down into carbon dioxide.Pyruvic acid is broken down into carbon dioxide.
Electron Transport ChainElectron Transport Chain
Uses high energy electrons to convert ADP to Uses high energy electrons to convert ADP to ATP ATP
34 more ATP molecules per glucose molecule 34 more ATP molecules per glucose molecule are produced in addition to the 2 ATP are produced in addition to the 2 ATP molecules produced during glycolysis.molecules produced during glycolysis.
Water is also a product.Water is also a product.
Glucose Glycolysis
Cytoplasm
Pyruvic acid
Electrons carried in NADH
Krebs Cycle
Electrons carried in NADH and
FADH2
Electron Transport Chain
Mitochondria
Respiration: AnOverviewRespiration: AnOverview
Mitochondria
Section 9-1
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FlowchartFlowchartSection 9-2
Glucose(C6H1206)
+Oxygen
(02)
GlycolysisKrebsCycle
ElectronTransport
Chain
Carbon Dioxide
(CO2)+
Water(H2O)
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Cellular Respiration
FermentationFermentation
Releases energy form food molecules in the Releases energy form food molecules in the absence of oxygen (anaerobic)absence of oxygen (anaerobic)
The two main types of Fermentation are :The two main types of Fermentation are : Alcoholic fermentation Alcoholic fermentation Lactic Acid FeremtationLactic Acid Feremtation
Alcoholic FermentationAlcoholic Fermentation
Occurs in yeasts and other microorganisms.Occurs in yeasts and other microorganisms. Converts pyruvic acid to ethyl alcoholConverts pyruvic acid to ethyl alcohol Causes bread to riseCauses bread to rise
Lactic Acid fermentationLactic Acid fermentation
Lactic acid is produced in your muscles during Lactic acid is produced in your muscles during rapid exercise.rapid exercise.
Lack of oxygen to the muscles- causes muscle Lack of oxygen to the muscles- causes muscle soreness.soreness.
Pyruvic acid is converted into lactic acidPyruvic acid is converted into lactic acid
Glucose
Glycolysis Krebs cycle
Electrontransport
Fermentation (without oxygen)
Alcohol or lactic
acid
Chemical PathwaysChemical PathwaysSection 9-1
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