Exercise and the Body

Responses to Exercise Using your notes, bullet point the following tables: Acute (Short Term) Chronic (Long Term)

Energy Systems What are energy systems for? What energy systems are there? What is ATP? ATP is stored in the………….

Summary of Energy Systems ATP-CP System Lactic Acid System Aerobic System Anaerobic Anaerobic Aerobic Very rapid Rapid Slow Chemical: CP Food: glycogen Food: CHO, Fat, Protein Very limited ATP Limited ATP Unlimited ATP Muscular stores Lactic Acid causes No fatiguing limited fatigue by-products Explosive, sprint 1 to 3 min duration Endurance 100m 400m Mararthon

ENERGY SYSTEMS Energy for muscular activity and other biological work comes from the breakdown of adenosine triphosphate (ATP). ATP loses one phosphate molecule and breaks down to Adenosine diphosphate. Since the store for A TP is limited, the body must regenerate its ATP as quickly as it is broken down. This regeneration connects the ADP and Pi together again to create ATP once more. This regenerating of ATP is done by the breakdown of fuel reserves. There are three energy systems for this ATP-PC system Lactic acid system Oxygen (or aerobic ) system

The ATP-CP System The ATP- PC system uses a chemical fuel reserve, Creatine Phosphate, which is stored in the muscle. This process is anaerobic meaning it does not require the use of oxygen for it to work. The supply of CP is limited and can only be used effectively for 10 seconds. When sufficient oxygen is available CP is regenerated ready to use again if needed.

The Lactic Acid System The lactic acid system uses the anaerobic breakdown of glycogen. Glycogen is in the form that carbohydrate is stored in the body (in the liver and in muscles). This process does not require oxygen. From the gycogen break down the end result of this is pyruvic acid. At this stage the pyruvic can follow two courses of action. In the first if insufficient oxygen is available for further breakdown the pyruvic acid becomes lactic acid and is stored until sufficient oxygen is present and it then becomes pyruvic acid again and begins its aerobic breakdown.

The Aerobic System The Aerobic system produces its energy by utilising oxygen. It is performed through a series of chemical reactions known as the Krebs Cycle. Here we have the continued breakdown of glycogen from when it becomes pyruvic acid and enters the mitochondria. Fats (and in extreme circumstances proteins) are also broken down here as they can only be broken down aerobically. The results are the regeneration of ATP molecules and the production of by-products - water and carbon dioxide.

THINGS TO THINK ABOUT: Q. What makes it difficult to sprint as fast as you can for more than one minute? Write a detailed answer in paragraph form.