1. Energy

2. Adenosine Triphosphate
1 Adenosine Phosphate Phosphate Phosphate
2 Adenosine Phosphate Phosphate Phosphate
ATPase
11
3 Adenosine Phosphate ENERGY Phosphate

3. • The energy released from the breakdown
of ATP to ADP + P is converted to kinetic and heat
energy.
• The bond then needs to be re-built to be broken
down again to create more energy.
• There are four ways that this is done in the body:
1. ATP System
2. Phosphocreatine system
3. Lactic Acid System
4. Aerobic Energy System

4. Phosphocreatine System
• Phosphocreatine is found in the sarcoplasm.
• When the enzyme ‘creatine kinase’ is present:
Phosphocreatine --------------> P + Creatine + Energy
• For every molecule of PC broken down, 1
molecule of ATP is produced.
• No fatiguing by-products are released
• Occurs between approximately 3-10 seconds
of exercise.

5. ATP production in the lactic acid
system
• Involves the partial breakdown of glucose.
• The enzyme ‘Phosphofructokinase’ is released
when levels of phosphocreatine drop, and begin
to break down the glucose molecules.
• These molecules break down into two pyruvic
acid molecules.
• When oxygen is not present, pyruvic acid is
converted into lactic acid by the enzyme ‘lactate
dehydrogenase’.
• For every mole of glycogen broken down, 2
molecules of ATP are gained.

6. The Aerobic System
NO
PYRUVIC ACID LACTIC ACID
OXYGEN
H2O
2 ATP
OXYGEN
ELECTRON
TRANSPORT CHAIN
ACETYL-COENZYME A
KREBS
CITRIC ACID
CYCLE
34
ATP
= Pyruvate Dehydrogenase

7. The Aerobic System
• If Oxygen is present then the pyruvic acid will convert into
oxygen, and then into acetyl co-enzyme A and then (due to
PDH) into citric acid until proceeding on to Krebes Cycle.
• In the Krebes cycle, 2 molecules of ATP are created.
• Then after entering the “electron transport chain” 34
molecules of ATP are created. Water is a by-product.
• Takes place in the mitochondria.

8. The relationship of:
intensity, hydrogen and oxygen
More
Muscle More ATP hydrogen is More oxygen
Exercise More glucose
contraction must be released in is required to
becomes is broken
requires more resynthesized the electron combine with
more intense down
ATP transport the hydrogen
chain

9. Energy From Fats and Proteins
FATS
• Fat is stored in adipose tissue as triglycerides.
• Requires more oxygen than the breakdown of glycogen.
• The presence of lactic acid inhibits the fat breakdown.
PROTEINS
• Our bodies only rarely use proteins for ATP re-synthesis.
• Only used when the body is in a state of exhaustion.

10. SUMMARY
ATP-PC SYSTEM LACTIC ACID AEROBIC
Site of reaction Sarcoplasm Sarcoplasm Sarcoplasm + Mitochondria
Oxygen present Anaerobic Anaerobic Aerobic
Fuel used Phosphocreatine Carbohydrates Carbohydrate and Fat
Active enzyme Creatine Kinase Phosphofructokinase Phosphofructokinase + Lipase
Enzyme activated by ATP increase Decrease in PC levels Decrease in insulin levels
Relative speed Very fast Fast Slow
By-products None Lactic Acid Carbon Dioxide and Water
Effects of by-products None Inhibits enzyme None as easily expelled from body
Energy Yield 1 2 38
Threshold 3-10 seconds 1-2 minutes Unlimited in sub-maximal exercise

11. OBLA (onset of blood lactate accumulation)
• The point where blood lactate concentration
rises to approximately 4mmol/l.
• It is also the point where lactic acid cannot be
removed quickly.
• The lactate threshold is reached at a certain
VO max. For elite athletes this will be at about
2
70-80%.

12. Excess post-exercise oxygen consumption
(EPOC)
“The amount of oxygen consumed during recovery above that which would
have ordinarily been consumed at rest.”
Made up of two main components:
• Alactacid Component – The fast replenishment stage
• Lactacid Component - The slow replenishment stage
Stage Time Oxygen used Function 1 Function 2 Function 3
Alactacid Completed Up to 4 litres Re-saturate Resynthesise Resynthesise
Stage within 2-3 myoglobin ATP PC
minutes with oxygen
Lactacid Can take up 5-10 litres Lactic acid Replenishment Re-balance
Stage to 2 hours removal of muscle body
glycogen temperature
stores

13. Energy sources used in aerobic energy system
GLYCOLYSIS BETA OXIDISATION
Carbohydrates Fats Proteins
Stored in the muscle as Stored in adipose tissue as Stored in muscle cells
glycogen triglycerides
Glucose Fatty Acids Amino Acids
ATTACHES TO FATTY
ACIDS AND
TRANSPORTED IN
BLOOD
OXYGEN
ACETYL - COENZYME Glucose = 38 ATP
Fatty Acids = 130 ATP
THROUGH AEROBIC ENERGY SYSTEM