From: Hal Finney (hal@finney.org)
Date: Sat Apr 19 2003 - 20:44:52 MDT
Harvey writes:
> Here is a brief explanation of the difference between animal proteins and
> veggie proteins. Animal proteins are "complete" proteins in that they are
> constructed of aminos preformed into the exact ratios required to make
> flesh. Therefore it is perfect for human consumption and direct
> utilization. However, veggie proteins are "incomplete" proteins. They do
> not contain all the amino acids in animal flesh, but contain subsets of the
> "essential" aminos. The "essential" aminos are those that cannot be created
> in the body, but must be eaten. Vegetarians then have to create other
> "non-essential" aminos out of the "essential" ones. Then, vegetarians have
> to assemble the aminos to create new proteins to be utilized in the body.
> This is the big difference between vegetarian protein sources and animal
> protein sources.
My understanding is that most proteins are broken down essentially all the
way into their constituent amino acids during the digestion process. One
page I found that describes this process (not very authoritative though)
is http://www.geocities.com/Athens/Forum/6100/1tamasAAproteins.html.
A few amino acids may still be bound together in pairs (dipeptides)
or triples (tripeptides) but most are broken down to singles.
These amino acids circulate in the blood, and they are used to build
proteins in the cells which need them. Some proteins do circulate in
the blood but I think these are mostly used for signalling and such.
Generally, proteins are built by cells at the point where they are used.
Based on this, I wouldn't expect much difference between eating animal
or vegetable protein in terms of whether or where proteins are reused
or torn down.
Hal
This archive was generated by hypermail 2.1.5 : Sat Apr 19 2003 - 20:55:47 MDT