Competency 4

THE BASICS OF PHOTOSYNTHESISAlmost all plants are photosynthetic autotrophs, as are some bacteria and protistsThey generate their own organic matter through photosynthesisFigure 7.2(a) Mosses, ferns, andflowering plants(b) Kelp(c) Euglena(d) Cyanobacteria

The Overall Equation for PhotosynthesisThe reactants and products of the reactionUnnumbered Figure 7.1LightenergyCarbondioxideWaterGlucoseOxygengas

Chloroplasts: Sites of PhotosynthesisPhotosynthesis occurs in the chloroplastsLeaves are major site of photosynthesis because they have more chloroplastsChlorophyll is the pigment that actually absorbs light energy for photosynthesis

Carbon dioxide enters and oxygen exits the leaf through stomataWater is absorbed by plants roots and travels to the the leaves via veinsChloroplasts

Are found in the cells of the mesophyll (green tissue in the interior of the leaf)Contain stroma, a thick fluidContain thylakoids, membranous disklike sacsGrana are the stacks that comprise the thylakoids

In photosynthesisEnergized electrons are boosted uphill and added to carbon dioxide to make sugarHydrogen is moved along with the electrons, so the redox process takes the form of hydrogen transfer from water to carbon dioxideSunlight provides the energy needed for the chloroplasts to split the water molecules

Photosynthesis is a two-step process: Light reaction and Calvin Cycle

The light reactions convert solar energy to chemical energy (ATP and NADPH)

The Calvin cycle makes sugar from carbon dioxide (carbon dioxide is reduced to glucose)

Figure 7.4LightChloroplastLightreactionsCalvincycleNADPADP+ P

Light reaction Energy in sunlight is trapped, O2 is released, and both ATP and the hydrogen-carrier molecule (NADPH = H) are formed

THE CALVIN CYCLE: MAKING SUGAR FROM CARBON DIOXIDEThe Calvin cycleFunctions like a sugar factory within the stroma of the chloroplastRegenerates the starting material with each turnThe inputs are carbon dioxide from the air and ATP and NADPH produced in the light reactions

Figure 7.13InputThree CO2Six 3-PGASixSix ADP + SixSixSix NADPSix G3PGlucose andother compoundsOutputFive G3PThreeThree ADPThree RuBPCalvincycle1234One G3P

The Overall Equation for Cellular RespirationA common fuel molecule for cellular respiration is glucoseThis is the overall equation for what happens to glucose during cellular respirationCellular respiration can make up to 38 ATP molecules for each glucose moleculeUnnumbered Figure 6.1GlucoseOxygenCarbondioxideWaterEnergy

The Metabolic Pathway of Cellular RespirationCellular respiration is an example of a metabolic pathway (metabolism)A series of chemical reactions in cellsAll of the reactions involved in cellular respiration can be grouped into three main stagesGlycolysisThe Krebs cycleElectron transport

A Road Map for Cellular RespirationCytosolMitochondrionHigh-energyelectronscarriedby NADHHigh-energyelectrons carriedmainly byNADHGlycolysisGlucose2PyruvicacidKrebsCycleElectronTransportFigure 6.7

Stage 1: GlycolysisA molecule of glucose is split into two molecules of pyruvic acidThe enzymes for glycolysis are located outside the mitochondria (dissolved in the cytoplasm)Glycolysis breaks a six-carbon glucose into two three-carbon moleculesThese molecules then donate high energy electrons to NAD+, forming NADHOxygen present next step Krebs CycleNO Oxygen present next step Fermentation

Glycolysis makes some ATP directly when enzymes transfer phosphate groups from fuel molecules to ADPFigure 6.9Enzyme

Stage 2: The Krebs CycleThe Krebs cycle completes the breakdown of sugarThe enzymes of this stage are found in the liquid inside the mitochondriaIn the Krebs cycle, pyruvic acid from glycolysis is first prepped into a usable form, Acetyl-CoAThe Krebs cycle extracts the energy of sugar by breaking the acetic acid molecules all the way down to CO2The cycle uses some of this energy to make ATPThe cycle also forms NADH and FADH2

Stage 3: Electron TransportElectron transport releases the energy your cells need to make the most of their ATPThe molecules of electron transport chains are built into the inner membranes of mitochondriaConverts ADP into ATPYields 34 ATP

Glycolysis = 2 ATPKrebs Cycle = 2 ATPElectron Transport = 34 ATPTOTAL = 38 ATP

FermentationWhen cells release energy in the absence of oxygen (anaerobic respiration)Produces QUICK energyTwo types:Alcoholic produces ethyl alcohol, carbon dioxide, and NAD from pyruvic acid and NADH (yeast and other microorganismsLactic Acid takes place mainly in muscle cells, pyruvic acid is turned into Lactic acid, makes you sore

F: converts light (solar) energy into chemical (glucose) energyB: photosynthesisF: Occurs in plants, some protists, and some bacteriaB: photosynthesisF: occurs in the chloroplasts of eukaryotesB: photosynthesisF: green pigment that traps light energy to do photosynthesisB: chlorophyllF: stacks of disks in stroma of chloroplastB: granaF: fluid b/t double membrane of chloroplastB: stroma

F: each individual disk that makes up the grana in a chloroplastB: thylakoidF: thylakoid (disk) of chloroplast is surrounded by membrane called?B: thylakoid membraneF: thylakoid disk contains ___ which trap light energyB: chlorophyllF: chemical equation for photosynthesisB: 6CO2 + 6H2O + light C6H12O6 + 6O2 F: reactants for photosynthesisB: 6 carbon dioxides, 6 waters, and lightF: products of photosynthesisB: 1 glucose and 6 oxygens

F: once glucose is produced, the glucose leaves the chloroplast and goes to the _B: mitochondria

F: Oxygen leaves the plant as a waste product through the pores of the leavesB: stomataF: 2 stages of photosynthesisB: light dependent reaction (light reaction) & light independent reaction (dark reaction)F: stage of photo. that requires light to make ATPB: light reactionF: stage of photo that does not require light to make glucoseB: dark reaction

F: another name for dark reactionB: Calvin cycle

F: requires oxygenB: aerobicF: does not require oxygenB: anaerobicF: converts chemical energy (glucose) into usable energy (ATP) in the mitochondriaB: cellular respirationF: ATP stands for ?B: adenosine triphosphateF: 3 stages of cellular respirationB: glycolysis, Krebs cycle (citric acid cycle), electron transport chainF: stage of cell respiration that is anaerobic B: glycolysis & fermentation

F: stage of cell resp that does not occur in the mitochondria. Occurs in the cytoplasmB: glycolysisF: stages of cell resp that produces 2 ATPsB: glycolysis and Krebs cycle (citric acid cycle)F: stages of cell resp that is aerobicB: Krebs cycle (citric acid cycle), and electron transport chainF: stages of cell resp that occurs in the mitochondriaB: Krebs cycle (citric acid cycle), and electron transport chainF: stage of cell resp that produces 34 ATPsB: electron transport chainF: folded membrane of mitochondria B: cristae

F: chemical equation for cellular respiration B: C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP F: reactants for cell respirationB: 1 glucose and 6 oxygensF: products for cell respirationB: 6 carbon dioxides, 6 waters, and 38 ATPsF: How is energy is released from ATP?B: when a phosphate breaks away forming ADP. When phosphate breaks away, a chemical bond is broken releasing energy.F: our ATP must be recycled. Cell respiration adds ___ back to ADP forming ATPB: phosphateF: 2 types of fermentationB: alcoholic & lactic acid

F: produces ethyl alcoholB: alcoholic fermentationF: produces lactic acid in mammals during rapid exercise; makes muscles burnB: lactic acid fermentation