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Photosynthesis and Cellular Respiration Mr. Stahl Biology

Mr. Stahl Biology. Molecule TypeEnergyDetails 5. Carbohydrate 4 cal / mg 36 ATP from glucose Most common molecule broken down to make ATP 6. Lipid hi

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Photosynthesis and Cellular Respiration

Photosynthesis and Cellular RespirationMr. StahlBiologyReview of ATP- Section 4.1

Molecule TypeEnergyDetails5. Carbohydrate 4 cal / mg 36 ATP from glucose Most common molecule broken down to make ATP6. Lipid hi mrs stahl 9 cal / mg 146 ATP from triglycerides Stores most of the energy in people7. Protein 4 cal / mg Infrequently broken down by cells to make ATP- used for other important bodily processes.3ChemosynthesisProcess through which some organisms use chemicals as a source of energy to build carbon based molecules.Ex- Deep sea hydrothermal vents hi mrs stahlFunctions of Photosynthesis1. Biochemical Process2. Plant Cells only3. Plant growth and development4. Builds plant cell walls= cellulose5. Helps regulate the Earths environment6. Removes CO2 from the airChloroplast-the organelle photosynthesis occurs inThree main parts are:Grana- stacks of coined shaped membranes.

6ThylakoidLittle disks inside the grana. They contain chlorophyll and other light absorbing pigments. Photosystems- light collecting units. They are proteins that organize chlorophyll and help create NADPH and ATP

StromaFluid that surrounds the grana inside the chloroplast. Calvin cycle occurs here

PhotosynthesisProcess of using sunlight as energy to make carbon compounds (glucose) to make food.Occurs in the chloroplastTwo processes: Light dependent reactions and Light independent reactions

Chlorophyll- the molecule in the chloroplast that absorbs the energy from the sunlight. Chlorophyll a- main photosynthetic pigment. Absorbs reds and violets and reflects greens and yellows.Chlorophyll b- accessory pigment. Absorbs blues and red / oranges and reflects greens and yellows. Green color in plants comes from the reflection of lights green wavelengths by chlorophyll.

Carotenoids are yellow-orange pigments which absorb light in violet, blue, and green regions.

When chlorophyll breaks down in fall, the yellow-orange pigments in leaves show through.Dont have to put this in your notes!!! Just a little fun fact!

Fall Foliage

So lets beginThe sunlight hits the leaves and CO2 is let in through the stomata (little pores) while H2O is let in through the roots.

Light Dependent Reactions or Light ReactionsRequires sunlightTake place in thylakoidsWater and sunlight are neededChlorophyll absorbs energyEnergy is transferred along thylakoid membrane then to light-independent reactionsOxygen is releasedPhotosynthesis is broken down into two different reactions!!!1stLight Independent ReactionsUses the energy (ATP and NADPH) transferred from the light dependent reactions to make sugars.Reactions occur in the stromaDoes NOT require sunlightCarbon dioxide is absorbed and used at this stage.Calvin Cycle- metabolic pathway found in the stroma of the chloroplast in which carbon enters in the form of CO2 and leaves in the form of sugar.

2nd

2. Sunlight3. WaterCarbon DioxideOxygenPhotosynthesis: Process through which light energy is captured and used to build sugars that store chemical energy.1. ChloroplastSugar (glucose)Calvin CycleEnergy carrying molecules- ATP and NADPH4. Thylakoid contains chlorophyllEquation

Calvin Cycle19Questions to review1. Where do the light dependent reactions occur? 2. Where do the light independent reactions occur?3. What two reactants are shown entering the chloroplast?4. What two products are shown leaving the chloroplast? 5. What does the Calvin Cycle produce? Answers1. Thylakoid membrane2. Stroma3. Water and carbon dioxide4. Oxygen and sugar5. Sugar- converts CO2 into sugarVideoshttp://www.youtube.com/watch?v=lDwUVpOEoE4

Now that we have a brief overview lets look at it in a little more detail.

Draw into notes!StepDescription Note sheet 4.31 Sunlight and water enters the chloroplast and goes into the thylakoid membrane. Photosystem II absorbs the light and uses it to split water into H+ ions, electrons, and O2. The O2 is given off as a waste product for heterotrophs to breathe. 2 High energy electrons from photosystem II move through the Electron Transport Chain (ETC- like a highway) to Photosystem I. Enzymes (NADP+) in the membrane use the electrons to make NADPH, which will be used in the Calvin Cycle.3 Inside of the membrane fills up with H+ ions making it positively charged and the outside is negatively charged. The difference in charges provides the energy to make ATP. H+ ions are really important!4 H+ ions cannot cross the membrane directly so they have to go through a big protein called ATP synthase, which rotates like a wheel. As it turns it binds ADP and a phosphate together to form ATP. 5 ATP and NADPH are produced and ready to be used in the Calvin Cycle / Light Independent Reactions.

Calvin Cycle occurs in the stroma1. CO2 enters the Calvin cycle and an enzyme called RuBP carboxylase (Rubisco) breaks down the carbon into a usable, organic form (carbon fixation). 2. The six-carbon molecule binds and utilizes a series of enzymes and energy is added. ATP and NADPH is used from LDR to split the six carbons into 2 groups of 3, and to keep the cycle going (reduction).3. Three carbon molecules exit and some are sent to the next step. After they both exit they bond together to form glucose.4. Three carbon molecules are recycled and changed back to five carbon molecules by energy from ATP. It takes two turns of the Calvin Cycle to produce 1 molecule of glucose.

RuBPVideoshttps://www.youtube.com/watch?v=joZ1EsA5_NY

Review Questions1. Where do the electrons come from in the ETC?2. What role do these electrons play?3. What two energy carriers are produced?4. When does active transport take place? 5. What enzyme speeds up the process?6. Where in the chloroplast do light independent reactions occur?7. Where does the ATP and NADPH come from for the light independent reactions?8. What does the LDR make? What does the LIR make?9. How many cycles or turns does it take to make one glucose molecule?10. What enzyme is used in the Calvin Cycle to bind with CO2 to fix it?Answers1. Chlorophyll- photosystem II and I2. Provide energy to move hydrogen ions into the thylakoid and to produce molecules of NADPH3. NADPH and ATP4. Step 3 when hydrogen ions are transported5. ATP synthase6. Stroma7. LDR8. LDR= makes ATP, LIR= makes sugars9. 210. RubiscoLets SummarizeProcessLocationReactantsEnding ProductsLight Dependent Reactions

Where the photosystems take place.Light Independent Reactions.

Where the Calvin Cycle takes placeWrite the Equation for PhotosynthesisLets SummarizeProcessLocationReactantsEnding ProductsLight Dependent Reactions

Where the photosystems take place.Thylakoid MembraneSunlightH2OATPNADPHO2Light Independent Reactions.

Where the Calvin Cycle takes placeStromaATPNADPHCO2Glucose C6H12O66CO2 + 6H2O -> C6H12O6 + 6O2Videoshttp://www.youtube.com/watch?v=k17bJQSQeQ4

Now we take photosynthesis and see how HUMANS and other organisms use it through a process called Cellular Respiration.

By the time you reach 16 you have taken about 200 million breaths

FUN FACT!Cellular Respiration!!Releases chemical energy from sugars and other carbon based molecules to make ATP when oxygen is present. Notes 4.4Animals use cellular respirationPlants use photosynthesisBreakdown food-> ATPAerobic-> Need OxygenAnaerobic= no oxygenTakes place in the Mitochondria

2 StagesStage 1= Krebs CycleStage 2= Electron TransportCellular Respiration Equation

Glycolysis happens first in the cytoplasm. Glucose gets broken down into 2-3 carbon chains. Produces 2 ATPGlycolysisOngoing process in all cellsLocation = cytoplasm outside of the mitochondriaAnaerobicMakes a small number of ATP molecules = 2 ATPSeries of reactions converts the three-carbon molecules to pyruvate / pyruvic acid. Pyruvate and NADH are used for cellular respiration.

Note Sheet 4.5Glycolysis

Draw into your notes!What is pyruvate?Our bodies actually make it naturally during metabolism and when we digest sugars and starches. It is crucial for the Krebs cycle in cellular respiration. A little extra, no need to copy.

6H O26CO 26O 2mitochondrionmatrix (area enclosedby inner membrane)

inner membraneATPATPenergyenergy from glycolysis1243andandandStep 1Pyruvate is broken down into 2 carbon molecules and CO2 is released as a waste product. NADH is produced

Step 2Coenzyme A bonds to the 2 carbon molecule made from pyruvate and enters the Krebs Cycle.No need to write: Acetyl-CoA is one of the most important molecules in the body because all nutrients (carbs, lipids, and proteins) generate it when they break down. This molecule is produced in large amounts and is pumped into the Krebs cycle if the body is in need of energy, or into synthesis of fat to be stored for later use.Step 3 Citric Acid is formed- the two carbon molecule binds with a four carbon molecule to make a six carbon molecule which is called citric acid. Step 4Citric acid is broken downNADH is madeCO2 is given off as a waste product.

Step 5Five carbon molecule is broken downFour carbon molecule, ATP, and NADH are formed.NADH leaves the Krebs cycle2 ATP are producedStep 6Four carbon molecules are rearrangedHigh energy electrons are releasedNADH and FADH2 (electron carrier) are made Krebs CycleMain function- transfer high energy electrons to molecules that carry them to the ETCOccurs in the matrix of mitochondriaAlso known as the Citric Acid Cycle

Step 7 on your diagramOne Molecule of Pyruvate makes these products:3 molecules of CO2 have been given off1 molecule of ATP4 molecules of NADH2 to the ETC1 molecule of FADH2 to the ETC

If Glycolysis produces 2 molecules of pyruvate, how much of each product do we have????Answer6 molecules of CO2 have been given off2 molecules of ATP8 molecules of NADH2 to the ETC2 molecules of FADH2 to the ETC

Electron Transport ChainTakes place along the inner membrane of the mitochondriaMade up of proteinsProteins use energy from NADH and FADH2 to pump hydrogen ions against the gradient (active transport)Step 1Proteins take electrons: 2 NADH and 1 FADH2. Step 2Proteins use energy from the electrons to pump the hydrogen ions through the inner membrane and the hydrogen ions build up on the inside of the membrane. Step 3ATP is producedFlow of hydrogen ions helps make the ATPATP synthase adds phosphate groups to ADP to make the ATP molecules. For each pair of electrons that passes through 3 ATP molecules are made. Step 4Oxygen enters and water is formed. Water is given off as a waste productEnd Result / Products of Cellular RespirationCO2 and pyruvate (from Krebs)H2O from the ETCNet gain of about 36-38 ATP molecules are made from 1 glucose molecule-> 2 glycolysis2 from Krebs Cycle32-34 from the ETC

PhotosynthesisCellular RespirationLocationChloroplastMitochondriaReactantsCO2 and H2OC6H12O6 and O2ProductsC6H12O6 and O2CO2 and H2OElectron Transport ChainProteins within the thylakoid membraneProteins within the inner mitochondrial membraneCycle of chemical reactionCalvin cycle in the stroma of chloroplasts builds sugar molecules.Krebs cycle in matrix of mitochondria breaks down carbon based molecules.What happens to your cells when there isnt enough oxygen to keep cellular respiration going?

Lactic Acid FermentationOccurs when oxygen is unavailableCauses your muscles to be sore / burnWhen oxygen is available your cells return to using cellular respiration and the lactic acid is broken down / removed. This is why you breathe heavy after exercising and it takes a few minutes to recover because your body is trying to recover from the oxygen depletion in your muscle cells.

Alcoholic FermentationForms the same way as the other two: Glycolysis splits a molecule of glucose to make 2 ATP, 2 pyruvate, and 2 NADH molecules. Occurs in many yeasts- CO2 causes the dough to riseEnd product is CO2, NAD+, and ethyl alcoholFermentation is used in food production.

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