The Energy Systems
•
Learning Objectives:
•
Don’t leave the room today unless you have learnt:
1. The re-synthesis of ATP to provide energy.
2. How this takes place through the bodies 3
energy systems.
3. The structure of the Phosphocreatine (ATPPC) System.
ATP
• ATP = adenosine triphosphate.
• ATP is the body’s only useable source of energy.
• Although we have other energy rich compounds like
phosphocreatine & glycogen, ATP is the only one that can be
utilised by the muscles to create movement.
The bonds are high energy!
How ATP provides energy:
• The problem is we only have enough stored to last for about 2 secs of
exercise. So to maintain exercise beyond this we have to re-synthesise it.
• ATP
ADP + P + Energy
ATPase
Key Questions
• 1. Where do you think the
energy is stored?
• 2. What is present to
assist in the breaking of
the bond?
• ATP
ADP +P + ENERGY
• This is exothermic which
means it gives out energy.
• ADP + P + ENERGY
• 3. What does this release
and how is this seen?
ATP
• This is endothermic which
needs energy to proceed.
• This is called a coupled
reaction. Why?
ATP Re-Synthesis
•
As ATP stores are low in our bodies it has to be resynthesised to allow us to keep exercising.
•
i.
ii.
iii.
This is achieved by the three energy systems:
The phosphocreatine system.
The lactic acid system.
The aerobic system.
•
What is it that determines which system is dominant?
•
The systems don’t work independently as two could be working
at the same time to re-synthesise ATP.
•
Remember the amount of ATP re-synthesise done by each
system depends on the intensity of exercise
The Phosphocreatine (ATP-PC) system.
•
This system uses another high energy compound known as
phosophocreatine to provide necessary energy to combine ADP and P.
High
energy
bond
1.
Creatine
kinase
Creatine
P
Exothermic
reaction?
Energy (to re-synthesise 1 molecule of ATP)
Creatine
&
P
2.
Endothermic
reaction?
Energy (from diagram 1)
Adenosine
P
P
P
3.
ATPase
Adenosine
P
P
P
High
energy
bond
Energy for exercise!!
Coupled Reaction
Creatine
kinase
• PC
P & C & energy
• energy & P & ADPATP
• A coupled reaction is when the energy produced in the
first reaction is used in the second reaction.
Summary.
• Can you complete the analysis table for the
ATP-PC system?
• The energy systems don’t make ATP, they
produce enough energy to re-synthesise ATP.
• What are the advantages and disadvantages
of the ATP-Pc system?
ATP is a most important compound.
Explain why ATP plays such a major role during
physical activity. (4)
• Jan 05:
• 3 marks
• 1. The only usable form of energy in the human body/energy
currency that powers all forms of biological work/immediate
• 2. A high energy phosphate compound/the outer two phosphate
bonds are high energy bonds/a store of potential energy
• 3. When the terminal phosphate bond is broken energy is
released/ATP is broken down to release energy/ ATP ADP + P +
ENERGY
• 4. An exothermic reaction
• 5. Facilitating enzyme is ATPase
• 6. Can be resynthesised (via the energy systems/with or without
oxygen)
• 7. The breakdown and resynthesis of ATP is a reversible reaction/
• ATP ADP + P + ENERGY
Define the terms energy, work and power,
giving the units of measurement for each. [3]
Jan 05.