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I will be able to explain how my body
converts food into a usable form of energy
for my cells and thus allows for movement.
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How does the human body generate energy?
Carbohydrates
Proteins
Fats
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Among the most
common organic
compounds on earth.
Digestion breaks down
carbohydrates into
glucose.
Glucose is stored in
the liver and skeletal
muscles in the form of
glycogen.
Glucose
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Metabolic pathways convert the chemical
potential energy in foods we eat into ATP.
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ATP fuels cellular processes in our bodies.
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ADP + P + Energy → ATP
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ATP video
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Anaerobic process that occurs in the
cytoplasm of cells.
First of the two anaerobic energy pathways.
Makes enough ATP to sustain intense activity
for about 15 seconds.
System involves breaking a phosphate group
off of phosphocreatine (PC) molecule and
adding it to ADP creating ATP.
PC + ADP → ATP + creatine
(Speed Skating Video – Men Team Pursuit)
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Allows athletes to participate in a high level
of performance for an additional 1-3
minutes.
Anaerobic process that occurs in the
cytoplasm.
Products of this reaction include ATP and a
molecule called pyruvate.
Pyruvate then moves on to the next pathway
which is aerobic.
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Pathway Overview Video
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In the absence of sufficient oxygen, pyruvate
is converted into lactic acid.
Lactic acid builds up in the muscle fibres and
causes pain and reduces movement.
The exercise intensity at which lactic acid
begins to accumulate within the blood is
known as the anaerobic threshold.
Anaerobic threshold level can be improved
with exercise for athletes involved in
endurance activities.
Read Chapter 5 (pgs 81 – 84)
1. List the three key energy nutrients.
2. What is the role of carbohydrates as an
energy source?
3. Why is ATP essential for life?
4. Compare anaerobic and aerobic systems.
5. List the type of activities that would use the
ATP-PC system and Glycolysis.
CHECK H/W