Energy Systems

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

ENERGY SYSTEMSEnergy 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 ATP 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

1. ATP-PC system 2. Lactic acid system3. Oxygen (or aerobic ) system

The ATP-CP SystemThe 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. CP is broken down into Creatine and Phosphate and the energy released from the breakdown is used to combine ADP and Pi to produce ATP. The supply of CP is limited and can only be used effectively for 10 to 20 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 . Carbohydrate is stored in the body as glycogen (in the liver and in muscles). This process does not require oxygen. From the break down of glycogen we get a bi-product called 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 SystemThe 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.

Summary of Energy SystemsATP-CP System Lactic Acid System Aerobic System

Anaerobic Anaerobic AerobicVery rapid Rapid SlowChemical: CP Food: glycogen Food: CHO, Fat,

ProteinVery limited ATP Limited ATP Unlimited ATPMuscular stores Lactic Acid causes No fatiguing limited fatigue by-productsExplosive, sprint 1 to 3 min duration Endurance100m 400m Marathon

WHAT HAPPENS TO OUR BODY IN EXERCISE?

Breathing rate gets deeper and faster:This is because the working muscle need more oxygen

to function. By breathing faster and deeper more oxygen is getting into the lungs. From here oxygen then enters the blood and is then pumped by the heart around the body to the working muscles.

Heart Rate Increases:The heart pumps blood and oxygen in the blood around

the body. When the body and the muscles in particular need more oxygen the heart pumps faster to get more oxygen to the muscles.

THE BODIES RESPONSE TO EXERCISE

Fill out the following table:

FUNCTION DESCRIPTION inc OR decr Amount Reason

HEART RATE 70bpm-average

PERSPIRATION Up to 1-litre in exercise

RESPIRATIONRATE

Up to 40-50 breaths during

exercise

STROKE VOLUME 70-80mls at rest

TIDAL VOLUME ½ l at rest and 2.5 l during

exercise

CARDIAC OUTPUT 4-6 l/min rest

THINGS TO THINK ABOUT:

There are many physiological changes in the body at exerciseWhat makes it difficult to sprint as fast as you can for more than one minute? Write a detailed answer in paragraph form.