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Alive & KickingThe Powerhouse Of The Human Body |
I think I must face the reality that I am addicted and, likely, most of the folks who live in Hugo, Centerville and Lino Lakes share the same dependencies: we must have oxygen and food.
I've traced my addiction to my mother who, I've realized now, shared the same problem, because as best I can tell the addiction was established before I was born.
Try as I would while passing my minutes in grade school, I would challenge the clock just to find that three minutes was as long as I could go without taking another breath and dragging in another load of the oxygen-nitrogen mix.
Have you ever wondered why you must breathe? No, not that you must breathe to live, but the real reason? What does the oxygen do? Where does it go? Does it accumulate? Where is it stored? In what form does it leave the body?
The answers to these questions can be found in a story about sunlight, food and energy.
Let's follow that oxygen and see where it goes.
The air we breathe goes to the lungs, an incredible transport system. If the inner surface areas of both lungs were spread out flat, they would likely cover a tennis court.
Lung composition is a bit like whipped Jello, except that it is highly organized into tiny air passageways ending in tiny, three-dimensional cul-de-sacs. Membranes separate these passageways and our smallest blood vessels (capillaries) travel through the membranes.
It is in these small, numerous air spaces that oxygen passes into the bloodstream, where most of it is picked up by red blood cells for distribution throughout all living human tissues - kind of like a microscopic UPS service - except it's red, not brown.
Most human cells are within two cells of an adjacent capillary. Oxygen enters these human cells by molecular movement and is available for the cells' use.
Now, let's consider energy.
Sunlight is the source of the energy we find in all our food. Green plants capture this energy and with it build the sugar, glucose.
I'm sure you have burned marshmallows over a campfire, proving that sugar will burn and release energy. During this burning, electrons are rapidly removed from the marshmallow as it flares on the stick, releasing the stored energy as heat and light.
In the living cell, a slow, controlled burning of sugar occurs and the excited electrons are removed from the food molecules. The electron energy is used to manufacture ATP-a high-grade "biological gasoline," which supplies the energy required by all plants and animals, from bacteria to elephants.
We use ATP to think, grow, move, and warm ourselves.
What happens to that cellular oxygen?
The de-energized electrons attract protons from fluids inside the cell to form hydrogen (H). Two of these join a single oxygen to make H2O, which we all know as water, (H+H+O=H2O), a stable, low-energy molecule. This water can be used by the cells and likely will leave the body by one pathway or another.
So, in summary:
. Without oxygen we cannot make more ATP, our "biological gasoline."
. We store almost no ATP or oxygen, which is why we must breathe continuously.
. If you are playing or working hard, you breathe harder to make more ATP.
. We do not use our oxygen to make CO2 (carbon dioxide). We use the oxygen we breathe to form water.
. Our brain's energy demands are great. Without enough oxygen, we pass out. Death will soon follow.
So keep breathing, and make lots of ATP. We do run on energy from sunlight!
Guest columnist John Cooke taught high school biology for 30 years and is pleased to share his insights with our readers.