Chicken run
When you eat chicken, have you noticed that the leg muscles are
darker in colour than the breast? This is because the leg muscles
contain far more myoglobins (¦Ù¬õ³J¥Õ) than the breast. As the leg muscles
are used for long-term activity, such as walking, they need a constant
supply of oxygen for releasing energy. The coloured myoglobins are
responsible for holding oxygen in the cells.
The leg muscles need a larger energy source
The energy carrier
The 1997 Nobel prize for Chemistry went to three biochemists for
the study of the important biological molecule, adenosine triphosphate
(ATP). They are Professor Jens C. Skou, Dr. John E. Walker and Professor
Paul D. Boyer.
ATP consists of an adenine (green), a ribose (red) and a phosphate
chain (purple)
The phosphates are the key to the activity of ATP.
ATP works by losing the endmost phosphate group in the presence
of an enzyme. This reaction releases a large amount of energy for
building proteins or muscle contraction, etc. The reaction product
is adenosine diphosphate (ADP), and the phosphate group either ends
up as orthophosphate (HPO4) or attached to another molecule (e.g.
an alcohol). Even more energy can be released by removing a second
phosphate group to produce adenosine monophosphate (AMP).
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