Notes on Energy Systems
Essay title: Notes on Energy Systems
Notes for Physical Education
The Energy Systems
What is ATP
When food is consumed some compounds contain energy
Body can not access energy directly and so is used in the form of Adenosine Triphosphate (ATP)
When ATP is broken down it releases energy
Sources of ATP
Protein-
Food including meat, fish, dairy, eggs
Only used as ATP in conditions of prolonged starvation
Carbohydrates-
Breads, cereals, fruits and pasta
Broken down into glucose and stored as glycogen in liver and muscles
Excess CHO converted into fat and stored in adipose tissue
Broken down into Fatty Acids and triglycerides
Fatty acids stored in adipose tissue pr circulate in the blood
Triglycerides stored in the muscles
Functions of ATP
Energy is stored in chemical bonds between two major ATP parts- ADP (adenosine diphosphate) and the third phosphate.
When electrical impulses at muscle stimulates ATP to break down into ADP
Used to power rowing motion of myosin cross bridges (muscle contracts)
Only small amounts of ATP in muscles
Once store is used up, chemical reactions occur to produce ATP
Production of ATP
3 chemical methods of producing ATP inside our muscles; 1) from the energy released from the break down of Creatine Phosphate, 2) from energy released when glucose is converted into lactic acid, 3) breakdown of CHO and fats using oxygen
ATP production during resting conditions
Any ATP required is produced aerobically
Occurs in mitochondria
At rest two fuels for aerobic energy production ; fats (two thirds) and CHO (one third)
ATP production during exercise
Depends on how long exercise (duration), wether or not vigorous exercise (intensity) and how well developed the persons cardio-respiratory system is.
Anaerobic only used when not enough oxygen to produce ATP is required.
ENERGY SYSTEMS
The ATP-CP system
supplies immediate energy
for maximal intensity and short periods (10seconds)
a molecule called Creatine Phosphate breaks down into Creatine and phosphate which releases energy used to rejoin ADP and phosphate to make ATP
very limited supply
Lactic Acid System (anaerobic glycolosis)
once CP stores become exhausted second anaerobic energy system takes over
stored glycogen obtained from CHO is converted into glucose
Then converted into pyruvic acid if not enough oxygen is supplied then lactic acid is formed.
Then converted into lactic acid.
After large build up of lactic acid fatigue and muscle discomfort set it.
Short term energy 20-90 seconds
Also supplies energy in short period beginning of longer activity.
Aerobic System
During exercise respiratory rate, tidal volume (depth of each breath), heart rate, stroke volume, cardiac output and arteriovenous oxygen difference all increase
If exercise is sub-maximal eventually oxygen supply will be sufficient to produce required ATP
Fuels for aerobic system are- glucose either from muscle tissue or from liver and fats- either triglycerides from the muscle or fatty acids from adipose tissue.