Chapter 4- Nucleic Acids and the RNAWorld
Metabolism: The ability to acquire particular molecules and use them in controlled chemical reactions
that maintain conditions suitable for life and that contribute to growth.
-Nucleic acid- monomer- nucleotides. 1. Aphosphate group 2.Asugar 3. Nitrogenous base. Phosphate is
bonded to sugar molecule which is bonded to nitrogenous base.
-Sugar: Organic compound with a carbonyl group (C=O) and several hydroxyl (OH) groups.
-Ribose has an –OH group bonded to the second carbon. Deoxyribose has an H instead at the same
-Purines: adenine, guanine
-Pyrimidines: cytosine and uracil (thymine)
-The polymerization reaction involves the formation of a bond between the phosphate group of one
nucleotide and the hydroxyl group of the sugar component of another. The result of this condensation
reaction is a phosphodiester bond.
-The sugar-phosphate spin is directional 5’ 3’
-The addition of one or more phosphate group raises the potential energy of the substrate molecules
enough to make an endergonic reaction possible. Phosphorylated nucleotides are activated.
Watson &Crick: Double helix, sugar-phosphate backbones outside of spiral and nitrogenous bases on the
inside. Complementary base pairing.
-DNA’s primary structure serves as a mould or template for the synthesis of a complementary strand.
-The lack of a 2’hydroxyl group on deoxyribon