Applied anatomy physiology: Energy systems (Anaerobic systems)

ATP-PC system intensity

very high

ATP-PC system duration

8-10 seconds

ATP-PC system fuel source

phosphocreatine

ATP-PC system ATP yield

1 ATP per PC molecule

Key sporting examples of ATP-PC system

60m sprint, 100m sprint, 1RM, tennis serve

Two anaerobic energy systems

ATP-PC and Anaerobic glycolytic

ATP-PC system

Anaerobic process which re-synthesises ATP when the enzyme creatine kinase detects high levels of ADP. Breaks down the phosphocreatine in the muscles to phosphate and creatine, releasing energy, which is then used to convert ADP to ATP in a coupled reaction.

ATP-PC system formula

PC -> Phosphate (Pi) + Creatine + Energy
Energy -> Pi + ADP -> ATP

Fatiguing by-products of ATP-PC system

None

ATP-PC system advantages (4)

• ATP can be re-synthesised rapidly

• PC stores can be re-synthesised quickly (30s = 50% replenishment, 3mins = 100%)

• No fatiguing by-products

• Can extend time of utilisation through use of creatine supplementation.

ATP-PC system disadvantages (3)

• Limited supply of PC in muscle cell (only lasts for 10 secs)

• Only one mole of ATP can be re-synthesised for every mole of PC (low yield)

• PC re-synthesis can only take place in presence of O2 (when intensity of exercise is reduced).

Anaerobic glycolytic system

Anaerobic glycolysis = breaks down glucose/glycogen without O2. GPP breaks glycogen into glucose. PFK controls glycolysis. 2 ATP used early, 4 ATP made later = net 2 ATP (3 from glycogen). LDH converts pyruvic acid into lactic acid (byproduct).

Anaerobic glycolytic system intensity

high

Anaerobic glycolytic system duration

Depends on fitness of individual and how how exercise intensity is, however can last up to 2-3 minutes.

Anaerobic glycolytic system fuel source

Glucose

Anaerobic glycolytic system ATP yield

2 molecules of ATP for one molecule of glucose broken down.

Anaerobic glycolytic system key sporting examples

High intensity activities lasting up to 3 minutes but peaking at 45 seconds, e.g. 400m.

Anaerobic glycolytic system fatiguing by-products

Lactic acid

Anaerobic glycolytic system advantages (4)

• ATP can be re-synthesised quite quickly due to the small amount of chemical reactions

• Lasts longer than ATP-PC

• In the presence of O2, lactic acid can be converted back into liver glycogen or used as fuel through oxidation into CO2 and H2O.

• Can be used for a sprint finish

Anaerobic glycolytic system disadvantages (2)

• Lactic acid as by-product - denatures enzymes and prevents them from increasing the rate of chemical reactions.

• Glycogen can only release a small amount of energy under anaerobic conditions (5% opposed to 95% under aerobic).

Anaerobic glycolytic system reaction

• GLYCOLSIS:
  Glycogen --> Glucose --> Pyruvic acid

• (BY)PRODUCTS:
  2 ATP, Lactic acid.

• No oxygen