Salam,
the answer is simple. The enzyme which digests cellulose in animals is absent in us
the answer is simple. The enzyme which digests cellulose in animals is absent in us
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The major component in the rigid cell walls in plants is cellulose. Cellulose is a linear polysaccharide polymer with many glucose monosaccharide units. The acetal linkage is beta which makes it different from starch. This peculiar difference in acetal linkages results in a major difference in digestibility in humans. Humans are unable to digest cellulose because the appropriate enzymes to breakdown the beta acetal linkages are lacking. (More on enzyme digestion in a later chapter.) Undigestible cellulose is the fiber which aids in the smooth working of the intestinal tract.
Animals such as cows, horses, sheep, goats, and termites have symbiotic bacteria in the intestinal tract. These symbiotic bacteria possess the necessary enzymes to digest cellulose in the GI tract. They have the required enzymes for the breakdown or hydrolysis of the cellulose; the animals do not, not even termites, have the correct enzymes. No vertebrate can digest cellulose directly.
More details:
http://www.talkorigins.org/faqs/vestiges…
http://dujs.dartmouth.edu/uncategorized/…
Nice one:
http://science.jrank.org/pages/1335/Cell…
Animals such as cows, horses, sheep, goats, and termites have symbiotic bacteria in the intestinal tract. These symbiotic bacteria possess the necessary enzymes to digest cellulose in the GI tract. They have the required enzymes for the breakdown or hydrolysis of the cellulose; the animals do not, not even termites, have the correct enzymes. No vertebrate can digest cellulose directly.
More details:
http://www.talkorigins.org/faqs/vestiges…
http://dujs.dartmouth.edu/uncategorized/…
Nice one:
http://science.jrank.org/pages/1335/Cell…