Download ATP Production via the 3 Metabolic Pathways (3 methods of

ENERGY PRODUCTION IN THE BODY
ATP is the body’s ‘universal’ Energy form (source)
-the enzyme ATPase breaks the bond between ADP + Pi releasing energy required for
contraction
ATP ---------------> ADP + Pi + Energy
ATPase
ATP Production via the 3 Metabolic Pathways (3 methods of production)
-muscle cells store limited amounts of ATP
-metabolic pathways exist in muscle cells allowing ATP production by any one or combination of
the 3 metabolic pathways:
1) CP – creatine phosphate formation of ATP
2) Glycolysis (breakdown of glucose/glycogen) to form ATP
3) Oxidative formation of ATP
-methods #1 and #2 do not involve Oxygen and therefore are called ANAEROBIC metabolism
-method #3 uses Oxygen and is therefore called AEROBIC metabolism
ANAEROBIC METABOLISM
#1) The Creatine Phosphate System (Phosphagen System)
CP + ADP --------------------> ATP + C
creatine kinase (catalyst)
-this is the simplest & most rapid way to form ATP
-can replace ATP as fast as the body breaks it down
-but muscle cells store only small amounts of CP, thus the amount of ATP able to form is limited
-this is called the “Phosphagen System” and provides energy for muscular contraction at the
onset of exercise and during short term high intensity exercise (~1 – 5 seconds)
-Activities: 50m run, high jump, clean & jerk, 10 yd run in football
#2) Glycolysis
-involves the breakdown of glucose or glycogen to form pyruvic acid or lactic acid
- an anaerobic pathway used to transfer bond energy from glucose to re-join Pi + ADP
-produces a net gain of 2 (or 3 depending if starting with glucose or glycogen) molecules of ATP
& 2 pyruvic or lactic acid per glucose molecule
#3 Aerobic ATP Production
(glucose contains large amounts of energy, eg 180 g of glucose = 686,000 calories)
-aerobic ATP production involves the Kreb Cycle to remove hydrogen from carbs / fats/ proteins
(accepted by NAD+ molecules)
-this hydrogen carries the potential energy used in the Electron Transport Chain to combine ADP
+Pi to reform ATP
-oxygen is the final acceptor (forms H20) as waste product)
-this process of aerobic production of ATP is called Oxidative Phosphorylation
note: 1 molecule of glucose produces 38 ATP via aerobic glycolysis vs 2 (or 3) in anaerobic