MICROBIAL GENETICS
CHAPTER ONE
The flow of genetic information in bacteria can be represented by:
The flow of genetic information in bacteria can be represented by:
As shown, there are two ways that genetic information can flow: Information is transferred between bacterial generations. This occurs when DNA replicates and is distributed to two identical daughter cells through the process of binary fission.
Information is transferred within the bacterial cell. The result of this transfer is proteins needed for cell growth and metabolism. Because DNA and protein have different chemical components, DNA must first be transcribed into mRNA and then translated into a protein. As these molecules and processes are vital to bacterial existence we will discuss each in some detail:
The macromolecules that play an important role in the flow of genetic information in bacteria are DNA, RNA and Protein. Here we examine the chemical structure of each.
Class Notes
[DNA/RNA Structure] [Complementation] [Antiparallel Strands] [Gene Definition]
[Bacterial Chromosome] [Protein Structure]
DNA and RNA Structure
DNA and RNA belong to a class of macromolecules called nucleic acids.
Nucleic acids are polynucleotides which means they contain many nucleotides joined together. A nucleotide consists of: One cyclic five-carbon sugar (The carbons found in this sugar are numbered 1' through to 5') One phosphate One nitrogenous base
The sugar is deoxyribose in DNA and ribose in RNA. The only difference between the sugars is that ribose has a hydroxyl group (OH) on the 2' carbon and deoxyribose does not. This makes deoxyribose more stable than ribose. The phosphate is linked to the 5' carbon of the sugar in both RNA and DNA. The nitrogenous bases are adenine(A), guanine(G), cytosine(C), thymine(T), and uracil(U). Adenine and guanine are purines (contains a six membered ring of carbon and nitrogen fused to a five membered ring).
Adenine and guanine are both found in DNA...
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