2 PhotosynthesisMost autotrophs create energy from the sun using photosynthesisThe overall equation is:6CO2 + 6H2O C6H12O6 + 6O2This occurs in Two Phases:Light ReactionThe Calvin CycleSUNLIGHT
3 6CO2 + 6H2O C6H12O6 + 6O2 Light-Reaction Phase: Photosystem II SUNLIGHTLight-Reaction Phase:Photosystem IIUses energy from light to break down H2OReleases O2Photosystem IHarnesses electrons from broken H2O molecules to produces NADPHChemiosmosisUses H+ ions from broken H2O molecules to harvest the energy to turn ADP into ATP
4 6CO2 + 6H2O C6H12O6 + 6O2 Calvin Cycle: SUNLIGHTCalvin Cycle:Uses CO2 and the energy stored in NADPH and ATP to produce Glucose (C6H12O6)
5 Alternate PathwaysThe environment effects a plant’s ability to perform photosynthesisTwo alternate pathways exist:C4 plantsCAM plants
6 Cellular Respiration C6H12O6 + 6O2 6CO2 + 6H2O + ATP Function: to harvest electrons from glucose to produce ATPOverall Equation:Three Stages:GlycolysisCitric Acid Cycle (CAC) [Kreb’s Cycle]Electron Transport Chain (ETC)C6H12O6 + 6O CO2 + 6H2O + ATP
7 Transition to the Citric Acid Cycle GlycolysisC6H12O6 + 6O CO2 + 6H2O + ATPGlycolysis is anaerobic, meaning that it does not require oxygen.Glucose is broken down yielding:Energy (ADP -> ATP)Electron carriers (NADH)PyruvateTransition to the Citric Acid CycleC6H12O6 + 6O CO2 + 6H2O + ATPRequires oxygen (Aerobic)Pyruvate converted to Acetyl CoA
8 Citric Acid (Kreb’s) Cycle C6H12O6 + 6O CO2 + 6H2O + ATPStep 1- Acetyl CoA Citric AcidStep 2- Citric Acid broken down:Energy (ADP -> ATP)Electron carriers: NADH & FADH2Waste CO2Step 3- Acetyl CoA and Citric Acid are regenerated to repeat the cycle.
9 Electron Transport Chain C6H12O6 + 6O CO2 + 6H2O + ATPA flow of electrons from electron carriers NADH & FADH2 are used to harness energyETC is AerobicFinal electron acceptor is OxygenH+ + O2 = H2ONet 36 ATP in Eukaryotes, 38 ATP in Prokaryotes
10 Anaerobic Respiration What happens when there is NO oxygen?Glycolysis can still occurKreb’s cycle and electron transport cannotInstead, pyruvate goes into the anaerobic process known as fermentationOccurs entirely in the cytoplasm and regenerates NAD+
11 Fermentation Two Types: Lactic Acid Fermentation- Pyruvate is converted into lactic acidIn muscle cells, occurs when body cannot supply enough oxygenIn microorganisms this occurs to make cheeses, yogurts, and sour cream.
12 Fermentation Two Types: Alcohol Fermentation Occurs in yeast and some bacteriaConverts pyruvate into CO2 and ethanolNAD+ is regenerated