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Food Basics
Revised 11/05/06
There are several major food groups that most
of us have heard about, but haven't really
thought about the connection between them.
The basic ones are carbohydrates, fiber,
fats and oils, proteins, and vitamins
and minerals.
Let's get this one out of the way first.
Minerals are trace elements the body
needs for its complex chemistry. Since
the body can't perform alchemically and
transmute one element into another, you
have to take these in via the foods
you ingest. Because these are trace,
scientists may not have identified all of
these.
Vitamins can be thought of as chemicals
that the body has lost the ability to
manufacture through the long course
of evolution. These mutations have
spread throughout all humans because
our diet would typically contain these.
(As I understand it, cats don't need
vitamin C so they must be able to
make it. If a similar mutation
happened to them, they would NOT
be able to supplement this in their
diet, so they would die and not
pass on the mutation.)
As the name suggests, these chemicals are
composed of carbon and water. Okay, not
exactly in this proportion of one
oxygen atom for every two atoms of
hydrogen (H-two-O), because when
plants make these compounds, they
take in water and carbon dioxide
and produce carbohydrates and pairs
of oxygen atoms (O2). When we
"burn" these in our bodies, we
run the reaction in the reverse, breathing
in oxygen, eating carbs, and breathing out
carbon dioxide and water vapor.
The important thing to realize is that
carbohydrates ONLY come from plants
(not industrial plants, living plants).
This is how plants store the energy
they take from the sun via photosynthesis.
Okay, there are tiny amounts of glucose
found in animals but not enough to be
considered a source of carbs. ONLY FROM
PLANTS.
Now carbs are not the most energy
dense storage system. Carbs only
provide four kilocalories per
gram while alcohol provides 7 and
fat, 9. Looking at it
from the other way, you'd need more
than twice as much carbs by weight
than fat.
But since plants are
not mobile they don't have to
worry about cutting down on weight.
And it takes a little extra energy
to convert fats into glucose so
there is an "energy tax" on using
this denser energy storage system.
(The only place you find fats in
plants are in the seeds which are mobile
as they need to disperse. They don't
move under their own but still weight
is a consideration.)
Fiber is basically what a chemist would
call an inverted form of starch. Complex
molecules can have a "right-handedness"
or "left-handedness". Just like you can't
rotate a right glove to make it a left
glove, the same can be true for molecules.
If a chemist synthesizes one of these
chemicals in a lab, they will get a mix
of left and right-handed molecules. But
almost all life can only function with
one but not the other. (Another argument
in support of a single common ancestor
that we all evolved from.)
So while starch is a digestable
long carbohydrate molecule, the invert
form, which we call cellulose, is not.
(The "ose" ending means it too is a type
of sugar, like glucose, sucrose, and fructose.)
Cellulose, found in the cell walls of
plants, can only be digested by a few types
of very primitive microbes. These microbes
are found in the stomachs of termites and
grazing animals like cows, but we don't
have them.
So, yes, sawdust is fiber. Not very tasty
fiber and the sharp edges could puncture the
intestinal walls, but it is fiber. And
like carbs, the ONLY source of fiber is
from plants.
If you have any ideas, suggestions, comments, etc.
as to either what
is or should be on this website,
or the Mueller Center in general,
please let us know.
To contact us:
Phone: 276-2874
Fax: 276-2817
Email: mugrap@rpi.edu
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