Cellular Energetics APEX (question 15) respiratory material
Explain the Krebs cycle -where does it take place? What does the reaction begin with? ( two things). What do these two molecules produce? What does the reaction end with? (Three things) -what is the primary goal of the Krebs cycle? How much ATP is gained?
The Krebs cycle takes place in the mitochondria and begins with oxaloacetic acid and Acetyl Coenzyme A to produce Citric acid. The reaction ends with oxaloacetic acid (which is reused at the beginning of the next cycle), NADH, and CO2) The primary goal of this reaction is to produce a large quantity of hydrogen ions in the form of NADH. They are used in the electron transport 2 ATP gained
Can ATP be stored?
ATP cannot be stored, the supply must be continuously replenished
What is the main energy currency in the body? How is it produced? What is the energy used for? Can ATP be stored? Why?
ATP is the primary source of energy for the body. ATP is produced by oxidation of proteins, carbohydrates, and fats. ADP + Pi = ATP The energy is used for active transport, synthetic function, muscle contraction and cell division and growth
Explain Oxidative Phosphorylation -what is NADH split into? -what does oxygen serve? What are the two end products of oxidative phosphorylation? - how is the CO2 removed from the body?
NADH is split into NAD, hydrogen and 2 electrons. The electrons are fed into the chemiosmotic mechanism and a proton gradient is generated across a membrane which drives ATP synthesis with the help of ATP synthase. Oxygen will serve as the final electron acceptor. The end products of oxidative phosphorylation are H2O and 34 ATP molecules. ATP is used to carry out Energy dependent processes in the body. CO2 is removed from the body by alveolar ventilation 34 ATP molecules gained
What are three energy sources of used for energy production?
Proteins, carbohydrates and fats
Explain Glycolysis. What is pyruvic acid converted to if there is oxygen and if there isnt oxygen? How many ATPs are gained?
The goal of glycolysis is to convert one glucose molecule to 2 pyruvic acid molecules -in the presence of oxygen pyruvic acid is converted to Acetyl Coenzyme A -in the presence of no oxygen pyruvic acid is converted to lactic acid and transported to the mitochondria Produces two ATP
What pathway is 2-3 DPG produced? When does this take place during glycolysis?
The pathway is Rapoport Luebering pathway and takes place halfway through glycolysis. The more glucose molecules that go through glycolysis the more 2-3 DPG produced
Is the phosphate bond a high or low energy bond?
The phosphate bond is a high energy bond
Explain the aerobic and anaerobic metabolism pathway!!! What are three processes? Explain each and every part! Look in apex/apex workbook to write this out and explain it
The three processes involved in aerobic glucose metabolism are glycolysis, Krebs cycle and electron transport
What is the primary substrate for ATP synthesis? What produces more ATP (anaerobic metabolism or aerobic metabolism)?
Glucose is the primary substrate used for ATP synthesis. Aerobic metabolism produces more ATP than anaerobic metabolism
Explain the lactic acid pathway - what is the final electron acceptor? Would pyruvic acid be used? What occurs if pyruvic acid isnt being used? -can the lactic acid pathway produce ATP? How? -what is the problem with this pathway?
OXygen is the final electron acceptor in electron transport, if there is no oxygen this reaction backs up. Pyruvic acid usually isnt used if there is no oxygen available, so pyruvic acid concentration increases. -the lactic acid pathway provides a way to convert pyruvic acid into ATP although just a small amount of ATP is produced The problem with this pathway is that lactic acid is the end product. The lactic acid pathway doesn't back up, it will release lactate into the ECF and the circulation. IF oxygenation isnt restored, then lactic acidosis can result.