Cellular Respiration and Fermentation. How energy goes from chemical bond to a usable form…. 1. SUN. 2. LIGHT ENERGY. 3. PHOTOSYNTHESIS. 5. RESPIRATION. 6. ATP (CELL ENERGY). 4. CHEMICAL ENERGY. Metabolism Overview. Organic Compounds & Oxygen. ATP. Energy for Life.
Cellular Respiration and Fermentation How energy goes from chemical bond to a usable form…
1. SUN 2. LIGHT ENERGY 3. PHOTOSYNTHESIS 5. RESPIRATION 6. ATP (CELL ENERGY) 4. CHEMICAL ENERGY Metabolism Overview
Organic Compounds & Oxygen ATP Energy for Life Carbon Dioxide & Water ADP and P Energy Production and Use in Cells
How do we use “food”? • Cellular respiration - The process of respiration is where organisms convert chemical energy into cellular energy, which is known as ATP. • Cellular respiration is similar to burning fuel (like gasoline combustion in your car).
Who and Where? • It occurs in both heterotrophs and in autotrophs - they both need ATP to use for cellular energy. • In the cells it begins in the cytoplasm and usually ends in mitochondria
Carbon Dioxide ATP Carbohydrates C6H12O6 + 6O2 6CO2 + 6H2O + ENERGY Oxygen Water In and Out - The chemical formula C6H12O6 + 6O2 6H2O + 6CO2 + ATP
Stage 1 - Glycololysis • A 6-carbon molecule of glucose is separated into two 3-carbon pyruvate molecules and makes some ATP and NADH. • This process occurs in 4 steps that take place in the CYTOPLASM and does not requireoxygen to be present.
6. Stage 1 steps: • 2ATP isusedto started the reaction… • 4ATPs are formed from the reactions • The yield is therefore 2ATPs • The other 2 ATPs go back into the cycle to start it over again.
Aerobic Respiration in Mitochondria • Aerobic Respiration has 2 stages: • Krebs Cycle • Electron Transport Chain
The Kreb’s Cycle aka the Citric Acid Cycle
8. Products of the Kreb’s Cycle • ATP • FADH2 • NADH • The FADH2 and the NADH then enter the electron transport chain
9. The products of the electron transport chain (ETC) • ATP • At the end of the ETC hydrogen ions and the spent electrons combine with oxygen molecules forming H2O • In aerobic respiration oxygen is the final (terminal) electron acceptor.
Wait!!! What if there is no oxygen? • If oxygen is NOT present the pyruvate produced during glycolysis continues on to anaerobic respiration. • Anaerobic respiration takes place in the cytoplasm.
Anaerobic respiration (Fermentation) • Anaerobic Respiration has 2 types: • Lactic Acid Fermentation • Alcoholic Fermentation
12. Lactic Acid Fermentation • Pyruvate is changed to lactate by removing two hydrogen. • This process is by bacteria and fungi to produce foods like yogurt and cheese. • Also used by muscle cells when oxygen is not present (called lactic acid build up.)
13. Alcoholic Fermentation • Pyruvate is changed to ethyl alcohol by first removing CO2 and then 2 hydrogen. • This process is used by yeast to prepare many foods and beverages. • The release of CO2 causes dough to rise.
14. Aerobic vs Anaerobic • The total amount of energy that a cell can harvest depends on the presence or absence of oxygen. • Aerobic (with oxygen) gains 36 ATP. • Anaerobic (without oxygen) gains 2 ATP.
Questions? • Living on Earth is expensive, but it does include a free trip around the sun every year.” --Unknown