Energy is the ability to do work and is transferred or converted between different forms. ATP provides energy for physiological processes through the breakdown of phosphate bonds. There are three main energy systems in the body: 1) ATP-PCr system provides short bursts of energy through phosphate transfer from creatine phosphate to ATP. 2) Lactic acid system provides moderate energy through anaerobic glycolysis but produces lactic acid. 3) Aerobic system provides sustained energy through oxygen-based breakdown of glucose and fats, producing water and carbon dioxide.

1. Energy Systems
Olivia Burkinshaw

2. What is energy?
 Energy is a property of objects which can be transferred to other objects or
converted into different forms.(Wikipedia 2016). The ‘ability of a system to
perform work’ is a common description. But it is misleading because energy is
not necessarily available to do work (Wikipedia 2016).
 ATP is a compound consisting of an adenosine molecule bonded to three
phosphate groups, present in all living tissue. The breakage of one phosphate
linkage (to form adenosine diphosphate, ADP) provides energy for
physiological processes such as muscular contraction. (Wikipedia 2015)

3. The first law of thermodynamics is
energy is neither created nor destroyed
just transformed.
Heat and light energy is
produced by the sun.
Contains chemical energy
Kinetic energy
Plants contain
chemical energy
ATP is then produced in
the mitochondria

4. What do we need energy for?
 Muscular contractions and movement- The source of the energy that is used
to power the movement of contraction in working muscles is ATP.
 Circulation-Better blood circulation can benefit the heart and other muscles
in the body and the arteries. Therefore the better the blood circulates this
means more oxygen is in the body.
 Transmissions of nerve impulses- a nerve impulse needs ATP to stimulate the
transmission.
 Digestion of foods- Nutrients in food gives the body’s cells the energy and
other substances they need to operate.
 Repairing and replacing tissues- As the tissues are constantly being repaired
this means it needs a source of energy at hand.

5. Overview of 3 energy systems
 The ATP-PCr System- ATP and creatine phosphate make up the ATP-PCr
system. At first PCr is broken down releasing a phosphate and energy, which is
then used to rebuild ATP. ATP is rebuilt by simply adding a phosphate to ADP,
this process if called phosphorylation.
 Lactic acid system- this system is capable of releasing energy to resynthesise
ATP without the use of oxygen and is called anaerobic glycolysis. Glycolysis
results in the formation of pyruvic acid and hydrogen ions.
 Aerobic system- this system produces far more ATP than either of the other
two energy systems but it produces the ATP at a slower rate, meaning it
cannot fuel intense exercise that demands the fast production of ATP.

6. Creatine Phosphate
 During this process the creatine phosphate molecule can be broken down
quickly and is used to turn ADP back into ATP. This system is most suitable for
single or continuous short bursts of energy, ranging from 10 seconds. For
example this system would be used for events such as the long jump and
javelin as these events only require short but powerful bursts of energy. The
amount of creatine phosphate in muscles is limited, which is why athletes
often use creatine phosphate supplements, therefore giving them an
advantage over other competitors.
 Every time your body does these intense exercises you body becomes use to it
and do you not only become fitter but your recovery time will begin to
decrease.

7. Lactic Acid System
 In comparison to the previous energy system this one provides energy for a
longer duration, usually ranging between 10 - 90 seconds. This energy system
is most likely used in a 100m swim, or a 400-800m run. During this process the
energy is a result from the fast break down of glucose from glycogen and
blood sugar, glycogen is stored in the liver and the muscles. As soon as
glycogen is broken down, it produces ATP and pyruvic acid. This process is
called anaerobic glycolysis due to the glycogen not being fully broken down,
however it does leave behind a product called Lactic Acid. When lactic acid is
produced your muscles begin to feel weak and fatigued.

8. Aerobic system
 The aerobic system releases energy slowly by using oxygen to breaking down
glucose. This system provides lots of long term energy suitable for every day
activities and endurance events such as long distance runs. As well as this it
can also break down fat to make ATP. The fitter we are the amount of oxygen
used by our muscles increases. The by products of the aerobic system are
water, which we sweat and CO2, which we exhale. This system is one of the
three that produces energy with oxygen, unlike the other two which can
produce energy without oxygen.
 In addition to this, this is a good system for people to lose weight as the body
begins to eat into the fat stored in order to increase the amount of energy
needed to run further.