Scientists believe polysaccharides played little role, if any, in chemical evolution. Which of the following is not true of polysaccharides, leading scientists to discount them as the first life- forms?
A) They are incapable of catalyzing chemical reactions.
B) Polysaccharides are polymers, meaning they contain many monomer subunits. Polymers have never been observed to form, in any type of molecule, under laboratory conditions.
C) The formation of glycosidic linkages between monosaccharides has been observed only with complex enzymes that would have come after chemical evolution-during biological evolution.
D) Because there is no complementary pairing between monosaccharides, they cannot provide the information for copying themselves.

Question

Quizplus · Accepted Answer

While polysaccharides are incapable of catalyzing chemical reactions, this is not a reason that scientists discount them as the first life-forms. The other three statements are reasons scientists discount polysaccharides as the first life-forms because they suggest that polysaccharides could not have formed without complex enzymes, have never been observed to form under laboratory conditions, and cannot provide the information for copying themselves due to the lack of complementary pairing between monosaccharides.

Scientists Believe Polysaccharides Played Little Role, If Any, in Chemical