BIOL 141 Lecture Notes - Lecture 3: Nitrogenous Base, Partial Charge, Adenine
24 Dec 2016
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Chapter 4: nucleic acids & rna of the world. Life began when chemical evolution led to production of molecule that could self-replicate. Rna world hypothesis: most scientists believe life began as a nucleic acid , specifically rna. Nucleotides have three parts: phosphate group, 5-carbon sugar (dna or rna, nitrogenous base (c, u, t are pyrimidines, adenine, guanine are purines) Chemical evolution could have led to the production of nucleotides, with ribose dominating deoxyribose. Nucleotides join together through phosphodiester linkages between the 3" (cid:697)oh(cid:698) in sugar and the oh in the phosphate group. This is a condensation reaction resulting in water as product: catalyst (enzyme) is used for phosphodiester reactions. Atp plays large part due to phosphates negative charge, repulsive property from each other"s negative charges, and large potential energy: nucleic acids could have formed without enzymes, but only 50-100 links could have been made based on research. So there was likely enzyme to produce millions of linkages for proteins.
