Anaerobic systems

Anaerobic systems

1. Lactic Acid System

   • Glycogen
     • Glucose-6-Phosphate
       • Pyruvic Acid
         • With insufficient oxygen
         • LDH
           • (Lactate Dehydrogenase)
         • Lactic Acid (2C3H6O3)
       • (Broken down by PFK - phosphofructokinase)
       • 2 ATP
   • Body switches to glycogen to fuel working muscles once phosphocreatine stores have been depleted.
   • Takes place in sarcoplasm
   • ATP resynthesised realtively quickly for activities from 10sec-3mins
   • doesn't need to wait 3 mins for sufficient oxygen
   • Any lactic acid accumulation can be converted back into liver glycogen or be used as metabolic fuel
   • Lactic acid system can be called upon for a bust of energy- eg in the 10,000m
   • Only a small amount of energy (5%) can be released in the absence of oxygen

2. ATP-PC System

   • Relies on Phosphocreatine (PCr)
   • PCr in sarcoplasm is broken down by creatine kinase
   • PCr --> creatine + Pi + Energy
   • Every molecule of PCr = 1ATP
   • Stores of PCr are limited
     • Only lasts for 5-10 seconds of exercise
   • Energy + ADP + Pi = ATP
     • (Coupled Reaction)
   • ATP can be resynthesised very rapidly by PCr
   • PCr stores replenished within 2-3 minutes of exercise stopping
   • No fatiguing bi-products which could delay recovery
   • Resynthesis can only take place with sufficient oxygen available