Presentation on theme: "“The Perfect Machine?”. “The Perfect Machine”? “The Perfect Machine?”"— Presentation transcript:
“The Perfect Machine?”
“The Perfect Machine”?
“The Perfect Machine?”
Why Does The Metabolism Of All Living Organisms Prevent Them From Being “Perfect Machines”
Autotrophic 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.
Heterotrophic 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.
Comparative Equations Photosynthesis: 6 H 2 O + 6 CO 2 + energy (sun) → C 6 H 12 O O 2 Aerobic Cellular Respiration: ) C 6 H 12 O O 2 → 6 H 2 O + 6 CO 2 + energy (ATP)
Different 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 pathways I. Anaerobic (oxygen absent) I.Lactic Acid Fermentation II.Alcoholic Fermentation II.Aerobic (oxygen present)
Cellular Respiration and Inefficiency 686 kcal/mol of energy stored in glucose ATP yields about 1.6 kcal/mol Aerobic 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)
Where Is The Rest of The Potential Energy From Glucose?
Ethanol & Lactic Acid
Pathway 1a: Lactic Acid Fermentation Where: Cytoplasm What: Glucose is split into 3 carbon pyruvate, then into two, 3 carbon molecules of Lactic Acid. Why: To recharge 2 ADP 2 ATP
Pathway 1b: Alcoholic Fermentation Where: Cytoplasm What: Glucose is split into pyruvate, then into 2 carbon molecules of ethanol and carbon dioxide Why: To recharge 2 ADP 2 ATP
How Does Aerobic Respiration Differ From Anaerobic Respiration?
Aerobic Respiration C 6 H 12 O O 2 6 H 2 O + 6 CO ATP food (glucose, a carbohydrate) oxygenwater carbondioxide
Aerobic Respiration 1.Glycolysis 2.Krebs Cycle 3.Electron Transport Chain
First Step of Aerobic Respiration: Glycolysis Where: Cytoplasm What: Glucose is split into two 3 carbon molecules called PYRUVATE Why: To recharge 2 ADP 2 ATP
Mitochondria 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
Second Step of Aerobic Respiration: The Krebs Cycle Where: Intracellular matrix of mitochondria What: Products of glycolysis broken down in a series of cyclical chemical reactions. CO2 is released as waste Why: To recharge 2 ADP 2 ATP
Third Step of Aerobic Respiration: The Electron Transport Chain Where: Cristae of mitochondria What: Electrons produced from breakdown in Krebs Cycle used to power synthesis of ATP Why: To recharge 34 ADP 34 ATP
Why is aerobic respiration so much more efficient?
Aerobic Respiration & ATP The waste byproducts of aerobic respiration are simpler (CO 2 ) Therefore, more energy is available to recharge ATP from ADP and Phosphate As a result of this higher efficiency, aerobic organisms can be more complex, active and have longer- life spans.