Unit 5
Nucleotides and Nucleic Acids

Overview

This unit consists of a single lesson in which we introduce the biochemical structure of genetic materials, and the biochemical processes involved in the creation of proteins from a genetic blueprint.

Objectives

After completing this unit, you should be able to

identify the basic chemical structures of the nucleic acid bases, of nucleotides and of nucleosides (both ribo- and deoxyribo- forms).
identify the standard abbreviations for the substances listed in Objective 1, above.
describe the flow of genetic information (DNA → proteins).
define the terms “chromosome,” “gene,” “virus,” and “plasmid.”
explain why we know more about bacterial genetics than about mammalian genetics.
name the three types of RNA.

Glossary

deoxyribonucleotide	monomeric building block of DNA; a phosphate group and a nitrogenous base both bonded to deoxyribose
duplex	two complementary strands of DNA
exogenous	from the outside
labile	unstable
mutant	genetically altered species or cell
nucleophilic attack	approach of a negatively charged chemical group close enough to a positively charged atom to bond
nucleoside	nitrogenous base bonded to ribose or deoxyribose
nucleotide	monomeric building block of RNA and DNA; a phosphate group and a nitrogenous base both bonded to ribose or deoxyribose
operon	area of a bacterial chromosome which contains a promoter site and the gene or genes for a related set of proteins
phosphodiester	two different alcohols forming ester linkages with one phosphate ion
replication	DNA synthesis
retrovirus	RNA-containing virus
template	a section of DNA which is being replicated or transcribed; mRNA which is being translated
transcription	synthesis of RNA from DNA
translation	synthesis of proteins from an RNA template