ENERGY SYSTEMS

1
ENERGY SYSTEMS

• A2 Physical Education

2
The Energy Currency

• Sometimes known as a nucleotide.
• Chemical compound containing base (adenine) a
  sugar (ribose) and phosphate groups (bonded to
  the sugar).

3
Storing energy
Energy trickling into your body from the
digestion of food
Re supply of energy
ATP
PCr
Blood Glucose
2 s
Muscle and Liver Glycogen
210 s
Fat (lipids)
Protein
503 g (2012 kcal)
12 304 g (110 700 kcal)
?
4
ATP Role

• Adenosine triphosphate (ATP) is the energy
  currency of the body it transfers energy from
  one molecule to another.
• All energy transfer within the body uses ATP
  (e.g. storage of glycogen and mechanical work for
  exercise).
• Without ATP work cannot be carried out it must
  be constantly replenished.
• Each cell of the body has about a billion
  molecules of ATP which are used, re-formed and
  reused and so on
• Energy transfer via ATP is controlled by the
  enzyme ATPase.

5
ATP

• Consists of an adenine molecule, a ribose
  molecule and three phosphate groups bonded
  together.
• Energy for forming ATP comes from the catabolism
  of glucose (known as cellular respiration).
• ADP P Energy ATP

6
ATP Splitting adenosine diphosphate

• ATP ATPase ADP and energy
• ADP P ATP
• The extra P comes from the Creatine Phosphate
  (CP) energy system.
• Hydrolysis (splitting) of ATP liberates 7.3 kcal
  of energy.

Draw on board
7
Coupled reactions

• Coupled reactions occur in pairs.
• The breakdown of one compound provides energy for
  building another compound.
• For example, if glucose is broken down the energy
  is stored as ATP.

8
Redox reactions at the smallest level

• Transfer of energy occurs via oxidation and
  reduction reactions (or redox reactions).
• Oxidation is the removal of electrons from a
  molecule decreasing potential energy.
• Reduction is the opposite accepting an electron
  from elsewhere resulting in an increase in
  potential energy.
• This usually occurs when dehydrogenase enzymes
  accept electrons from hydrogen
• NAD (Nicotinamide Adenine Dinucleotide)
• FAD (Flavin Adenine Dinucleotide)

9
Exothermic and endothermic reactions

• Exothermic (also known as exergonic)
• Produce more energy than they consume (give off
  energy)
• E.g. break down of complex molecules to smaller
  ones
• Such as glycolysis, Krebs and electron transport
• Endothermic (also known as endergonic)
• Consume more energy than they produce
• E.g. combining simple molecules to form more
  complex ones
• Formation of amino acids (peptide bonds) in
  muscle hypertrophy

10
The Energy Systems

• ATP-PCr (immediate)
• Lactic acid (short-term)
• Aerobic (long-term)

GROUPS - What do you know about each of these
energy systems? - What fuels are being used? -
Consider duration and intensity of exercise?
11
The Energy Systems
12
The Energy Systems
13
The Energy Systems
14
The Energy Systems

1. Immediate energy (ATP-PCr system) approx. 610 s
2. Short-term energy (Lactic Acid system) approx. 2
   min
3. Long-term energy (Aerobic system) more than 2
   min

15
The Energy Systems
Immediate ATP-PCr
Short-term Lactic acid (glycolysis)
Long-term Aerobic
16
Exam Question

• With the use of an example for each, explain the
  terms exothermic, endothermic and coupled
  reactions.
• (6 marks)