5Why Does The Metabolism Of All Living Organisms Prevent Them From Being “Perfect Machines”
6Autotrophic Energy Flow Autotrophs (producers) get their energy from the sun.Producers convert this light energy into stored chemical energy (glucose).This process is called photosynthesis.
7Heterotrophic Energy Flow Heterotrophs (consumers) get their energy from the Autotrophs (producers).Heterotrophs convert the stored chemical energy of glucose into usable chemical energy (ATP).This process is called cellular respiration.
8Comparative Equations Photosynthesis:6 H2O + 6 CO2 + energy (sun) → C6H12O6 + 6 O2Aerobic Cellular Respiration:C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy (ATP)
10Different Types of Cellular Respiration Cellular respiration is a CATABOLIC reaction, meaning materials are broken down to provide energy for other substances to be “built up” (ATP)Cellular Respiration may follow two distinct pathwaysAnaerobic (oxygen absent)Lactic Acid FermentationAlcoholic FermentationAerobic (oxygen present)
11Cellular Respiration and Inefficiency 686 kcal/mol of energy stored in glucoseATP yields about 1.6 kcal/molAerobic Respiration recharges 36 net ATP (40.6% efficient)Lactic acid fermentation or alcoholic fermentation yield 2 net ATP, or about 4 kJ (2.5% efficient)
12Where Is The Rest of The Potential Energy From Glucose?
19Glycolysis Krebs Cycle Electron Transport Chain Aerobic RespirationGlycolysisKrebs CycleElectron Transport Chain
20First Step of Aerobic Respiration: Glycolysis Where: CytoplasmWhat: Glucose is split into two 3 carbon molecules called PYRUVATEWhy: To recharge 2 ADP 2 ATP
21Mitochondria Form & Function Plant and animal cells contain mitochondria: cell structures that transfer some of the chemical energy in glucose to ATP.In the mitochondria, a cytoplasm-like MATRIX is surrounded by a folded membrane with high surface area called the CRISTAE
22Second Step of Aerobic Respiration: The Krebs Cycle Where: Intracellular matrix of mitochondriaWhat: Products of glycolysis broken down in a series of cyclical chemical reactions. CO2 is released as wasteWhy: To recharge 2 ADP 2 ATP
23Third Step of Aerobic Respiration: The Electron Transport Chain Where: Cristae of mitochondriaWhat: Electrons produced from breakdown in Krebs Cycle used to power synthesis of ATPWhy: To recharge 34 ADP 34 ATP
24Why is aerobic respiration so much more efficient?
25Aerobic Respiration & ATP The waste byproducts of aerobic respiration are simpler (CO2)Therefore, more energy is available to recharge ATP from ADP and PhosphateAs a result of this higher efficiency, aerobic organisms can be more complex, active and have longer-life spans.