Energy Systems Flashcards
ATP
Major source of potential energy
Second degree high energy bonds linking phosphates
Body stores ____ of ATP
80-100 grams
Demand is met through constant synthesis
Creatine Phosphate System
Immediate energy
Most likely depleted within 20-30 seconds
Muscles store more PCr than ATP
Once PCr is used to create ATP, the remaining creatine is___
Shuttled from the cytosol into the mitochondria where it picks up another phosphate
Lactic Acid System
Anaerobic metabolism
Supplied from glucose or stored glycogen
Lasts 60-180 seconds
Glycolysis
The dissolution of sugar
10 step process by which glucose is broken down to create energy
About 5% of the total possible energy of a glucose
Phosphofructokinase
Rate limiting enzyme in glycolysis reactions
Oxygen effect on Glycolysis
Inhibits glycolysis
Lactate
End product of glycolysis during intense exercise
Energy source during recovery from exercise
Lactate used as a source of energy by the liver, kidneys, and heart
Lactate threshold
Signifies the onset of appreciable lactate formation in muscle cells
Increase in the amount of lactate lowers pH of blood—>metabolic acidosis—->cessation of exercise
Aerobic System
Primary means of energy production at rest
RQ: .75-.82
Provides nearly all of the energy transfer beyond several minutes of exercise
Oxygen consumption Aerobic Exercise
Rises exponentially during the first minutes of exercise before it plateaus. Creates an oxygen deficit in the early stages of exercise
Oxidative phosphorylation
Coupled with electron transport chain, synthesizes ATP by transferring electrons to oxygen
Net ATP production of 32
Citric Acid Cycle
Process of extracting energy from pyruvate
Pyruvate converts to Acetyl-CoA which enters the cycle
Acetyl-CoA joins with oxaloacetate forming citrate that proceeds through the cycle
Electron Transport Chain
Majority of ATP is generated by the hydrogens created during the citric acid cycle and oxidized by the aerobic process of the ETC
