60 likes | 187 Views
Enduring Understanding: Growth, reproduction and maintenance of the organization of living systems require free energy and matter. Essential Knowledge 2.A.2: Organisms capture and store free energy for use in biological processes.
E N D
Enduring Understanding: Growth, reproduction and maintenance of the organization of living systems require free energy and matter Essential Knowledge 2.A.2: Organisms capture and store free energy for use in biological processes
Heterotrophs capture free energy present in carbon compounds produced by other organisms? • How do organisms produce ATP in the absence oxygen? • Fermentation (glycolysis + fermentation = anaerobic respiration) • What type of organisms use fermentation? • Facultative Anaerobes- an organism that makes ATP by aerobic respiration when oxygen is available but switches to fermentation when oxygen is not available • Obligate Anaerobes – carry out only fermentation (anaerobic respiration) and cannot survive in the presence of oxygen
Glucose Glycolysis CYTOSOL Pyruvate O2 present: Aerobic cellular respiration No O2 present: Fermentation MITOCHONDRION Acetyl CoA Ethanol or lactate Citric acid cycle
Heterotrophs capture free energy present in carbon compounds produced by other organisms? • What are the two types of fermentation? • Alcoholic Fermentation • Lactic Acid Fermentation • Is ATP produced during fermentation? • NO – but fermentation allows glycolysis to continue to make a net gain of 2 ATP per glucose by oxidizing NADH to NAD+. • In fermentation as NADH is oxidized a carbon compound is reduced.
Heterotrophs capture free energy present in carbon compounds produced by other organisms? • Pyruvate is converted to ehtanol in two steps • Step 1 releases CO2 from pyruvate leaving acetaldehyde • Step 2 oxidized NADH to NAD+ and reduced acetaldehyde to ethanol • Occurs in bacteria, yeast, and some plants • Pyruvate is converted to Lactacte in one step • Pyrvuate is reduced to lactate as NADH is oxidized to NAD+ • Occurs in bacteria, fungi, and human muscle cells Alcoholic Fermentation Lactic Acid Fermentation
2 ADP + 2 Pi 2 ATP Glucose Glycolysis 2 Pyruvate 2 NAD+ 2 NADH CO2 2 + 2 H+ 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation 2 ADP + 2 Pi 2 ATP Glucose Glycolysis 2 NADH 2 NAD+ + 2 H+ 2 Pyruvate 2 Lactate (b) Lactic acid fermentation