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| Climbing, as Im
sure many of you know, is a very intense sport that puts an extreme
amount of strain on your body. Tendon and ligament injuries are common
amongst climbers that render themselves useless for months at a time.
This following sequence of articles are going to focus on the biology
of climbing; things you can do to keep yourself on the rock instead
of on the couch.
How your body makes the energy that keeps you climbing
In all living cells, energy is temporarily packaged within a remarkable
chemical compound called adenosine triphosphate (ATP), which holds
a readily available energy for very short periods of time. We may
think of ATP as the energy currency of the cell. When you work to
earn money, you might say that your energy is symbolically stored
in the money you earn. The energy the cell requires for immediate
use is temporarily stored in ATP, which is like cash. When you earn
extra money, you might deposit some in the bank; similarly, a cell
might deposit energy in the chemical bonds of lipids (fats), starch,
of glycogen. Moreover, just as you dare not make less money than
you spend, so too the cell must avoid energy bankruptcy, which would
mean its death. Finally, just as you do not keep what you make very
long, so too the cell continuously spends its ATP, which must be
replaced immediately.
Humans use a form of cellular respiration requiring oxygen which
is called aerobic respiration. During aerobic respiration, nutrients
are catabolized to carbon dioxide and water. The cells of your body
use this method to obtain energy from glucose. Glucose is transformed
from many different chemicals in the foods you eat. Certain foods
contain more glucose than others, which yield more energy. But that
doesnt mean you should eat these foods only, as other low
energy foods contain many nutrients your body needs to build muscle,
bone, and cells. The following formula shows this process:
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(For you anti-chemistry people)
Glucose + oxygen + water gives you carbon dioxide + more water + energy
to pull down hard. |
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Aerobic respiration has four stages: |
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Glycolysis: |
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A six-carbon glucose molecule
is converted to two, three-carbon molecules of pyruvate, and ATP and
NADH are formed. |
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| 2. |
Formation of acetyl coenzyme
A: |
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Each pyruvate enters a mitochondrion
(a tiny body inside of a cell that makes energy) and is oxidized to
a two-carbon group that combines with coenzyme A, forming acetyl coenzyme
A. NADH is produced and carbon dioxide is released as a waste product. |
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| 3. |
The citric acid cycle: |
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The acetate group of acetyl
coenzyme A combines with a four-carbon molecule to form a six-carbon
molecule. In the course of cycle, citrate is recycled to oxaloacetate
and carbon dioxide is released as a waste product. Energy is captured
as ATO and then reduced as high energy compounds NADH and FADH2. |
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| 4. |
The electron transport chain
and chemiosmosis: |
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The electrons removed
from glucose during the preceding staged are transferred from NADH
and FADH2 to a chain of electron acceptor compounds. As the electrons
are passed from one electron acceptor to another, some of their energy
is used to pimp hydrogen ions (protons) across the inner mitochondrial
membrane, forming a proton gradient. In a process known as chemiosmosis,
the energy of this proton gradient is used to produce ATP. |
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| Its the simplest way
I could explain; this is how your body moves, lives, functions. Any
cell in your body goes through this process if it wants to do its
job correctly. At any one time there are trillions of molecules of
ATP being used up. Yes, that is trillion, with this many zeros; 000,000,000,000,000.
And that is the basics of how your body has the energy to move.
Now, with the normal process I just told you about, each reaction
produces about 34-38 ATP molecules. This is the normal rate of production
of ATP, and is what you would like. There are circumstances though
when your cells need more oxygen then the body can supply. And as
I stated earlier, normal cellular respiration requires oxygen to
carry out the production of ATP. When this begins to happen the
cells immediately switch over to a process that doesnt need
oxygen to produce ATP and you notice a burning in the muscles, and
might feel a little off. This is a lactic acid build
up from an emergency production of ATP called fermentation. And
this is a very inefficient process. Each time it goes through the
motions, it only creates 4 ATP molecules. But, in return for these
measly 4 ATP molecules, it releases a toxin into the body in either
the form of lactate or alcohol. Humans can only go on like this
for a few minutes before the cells just stop functioning. This is
why sprinters cant sprint for minutes at a time. The cells
are not capable of producing the needed ATP to function, and therefore
cease all normal activities.
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Resources
Biology, 5th edition, Solomon, Berg, Martin
Principles of Anatomy and Physiology, 6th edition, Tortota, Anahnostakos
Physical Examination and Health Assessment, Jarvis |
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