August 29th 2013 MSCI 311 Energy Metabolism If oxygen is present why does aerobic respiration take place instead of anaerobic with other molecules Aerobic respiration releases the most amount of energy Entropy always increases so more energy is released means more entropy means more ATP is produced What is all this energy used for in the cell How does cell harvest this energy to do work Digestive process in cell ingest by phagocytosis moved through cell via cytoskeleton fuse with lysosome enzymes from lysosomes break it down into constituent parts broken down parts are used to drive ATP production Molecules involved in respiration glucose fructose pyruvate acetyl CoA citric acid oxaloacetate ATP Aerobic and anaerobic both start with glycolysis in the cytoplasm aerobic continues on to mitochondria Glucose oxygen carbon dioxide water Glycolysis happens in everything Energy requiring steps of glycolysis o Glucose to PGAL Energy producing steps o Produces 4 ATP two reduced coenzymes yields two ATP o Left with two pyruvate end product of glycolysis Glycolysis one molecule of glucose is transformed into 2 molecules of pyruvate yielding two net ATP To begin Kreb s cycle we must move into the mitochondrion Mitochondrion outer membrane two layers inner outer compartment to max SA for Rx inner membrane Krebs cycle citric acid cycle go through twice o 2 pyruvates enter get broken down and end up giving off six CO2 o NAD takes pyruvate and forms acetyl CoA then forms citric acid Electron Transfer Chain o Energy input splits Hydrogen in protons and electrons o Electrons transferred through an electron transfer system with use of proteins o Some released energy is used to make ATP o Spent electrons and free oxygen form water o Occurs in in membrane of mitochondrion o Energy from transferring electrons is used to pump H ions across membrane forms a H concentration gradient H goes through ATP synthase We get 32 ATP from e transport chain 2 from krebs and 2 from glycolysis Understand where ATP are coming from know details for exams be able to fill in a chart of the processes Oxygen is the final acceptor of electrons because it produces the most amount of energy compared to other possible electron acceptors Blue crabs are declining o Pathogens and pollutants impair blue crab metabolic processes aerobic respiration o A certain kind of natural bacteria impairs crab ability to incorporate oxygen in metabolism o Too much glucose building up not enough oxygen to break it down not producing ATP they need not enough energy to grow reproduce o They breath enough to stay alive not enough oxygen getting into actual tissues to break down glucose Anaerobic respiration o Alcoholic fermentation Begins with glycolysis then produces ethanol by adding water to the pyruvate releases carbon dioxide to form 2 acetaldehyde e H from NADH form two ethanol o Lactate fermentation yogurt cheese sore muscles Begins with glycolysis pyruvate pick up H and e from NADH to form 2 lactate o Both produce way less energy only 2 molecules of ATP for each glucose molecule o Some anaerobes undergo e transfer but final e acceptor isn t oxygen so anaerobic respiration by bacteria uses other e acceptors More complex diversified organisms are able to form once oxygen and aerobic respiration occurred because there s much more energy to produce bigger and more organisms more energy to grow reproduce Overall size of fish becomes smaller and smaller