Nucleic acids in bacteria

Sulfonamides are used for controlling urinary tract infections, acute and chronic lung infections (norcadiosis), protozoan infections of the nervous system (i.e., toxoplasmosis), and a variety of infections in humans and livestock. Their mode of activity is by inhibiting the multiplication of bacteria by competitively inhibiting para-aminobenzioc acid (PABA) in the folic acid metabolism cycle (O Neil et al., 2001). More specifically, they block the synthesis of folic acid in bacteria as the drugs are structurally similar to PABA. Folic acid is essential to the synthesis of amino acids and nucleic acids. In bacteria, folic acid is synthesized from PABA... 

The pyrimidine portion of thiamin (Fig. 25-21) is distinct in structure from the pyrimidines of nucleic acids. In bacteria it originates from the purine precursor 5-aminoimidazole ribotide, which is converted into a hydroxymethylpyrimidine (Fig. 25-21 )373 which is... 

With the onset of the Second World War, Stephenson studied acetone-butyl alcohol fermentation as a means of synthesis of industrial solvents. Of greater importance was her work on pathogenic bacteria and her contributions to the MRC Committee on Chemical Microbiology. After the War, she studied the bacterial synthesis of acetylcholine in sauerkraut, while her last years were spent on an investigation of nucleic acids in bacteria and of their breakdown by enzymes within the cells. 

Biologic observations of the formation of viral nucleic acid in bacteria and of the replication of bacterial chromosomes have essentially substantiated this mechanism, although a host of individual problems remains to be solved. 

The amount of nucleic acid in tissues varies from 0.1% in yeast and 0.5-1% in muscle and in bacteria to 15-40% in thymus gland and sperm cells. In these latter materials of high nucleic acid content it is clear that multiplication of % N by 6.25 is not a valid measure of protein content. For diploid cells of the body the DNA content per cell is nearly constant. 

From the complementary duplex structure of DNA described in chapter 25, it is a short intuitive hop to a model for replication that satisfies the requirement for one round of DNA duplication for every cell division. In chapter 26, DNA Replication, Repair, and Recombination, key experiments demonstrating the semiconservative mode of replication in vivo are presented. This is followed by a detailed examination of the enzymology of replication, first for how it occurs in bacteria and then for how it occurs in animal cells. Also included in this chapter are select aspects of the metabolism of DNA repair and recombination. The novel process of DNA synthesis using RNA-directed DNA polymerases is also considered. First discovered as part of the mechanisms for the replication of nucleic acids in certain RNA viruses, this mode of DNA synthesis is now recognized as occurring in the cell for certain movable genetic segments and as the means whereby the ends of linear chromosomes in eukaryotes are synthesized. 

CRP binds not only the polysaccharides present in many bacteria, ftmgi, and protozoal parasites but—in the presence of free calcium ions—phosphorylchofine phosphatidylcholines, such as lecithin and polyanions, such as nucleic acids. In the absence of calcium ions, CRP also binds polycations, such as histones. 

Plant and animal remains, representing the main types of carbon compounds added to the soil, contain the carbon included in high-molecular weight compounds. In plants the main types of these are cellulose, hemi-cellulose and lignin, followed by smaller quantities of fats, waxes and oils, proteins and nucleic acids. In invertebrates and fungi chitin occurs, whereas in bacteria it is peptidoglycan (murein). 

Belozersky AN On the species specificity of the nucleic acids of bacteria. In The Origin of Life on the Earth. Edited by Oparin AI, Pasynskii AG, Braun-shtein AE, Pavlovskaya TE, Glark E Synge RLM. London Pergamon Publishers 1959 322-331. 

Many biosertsors that employ TSM resonators are available on the market today. Depending on their design, they can detect biological entities such as nucleic acids, viruses, bacteria, and cells. An example of TSM-based biosensor was presented by Davis et al. [16]. They used a coating of human IgG and subsequently used a TSM resonator to detect the presence of sheep antihuman IgG as marked by the decrease in the resonant frequency, signifying an increase in the mass loading from the attachment of the antibodies [16]. 

Vaccines, which nsnally involve viruses or nucleic acids in some way or another, have been known since Jenner nsed cowpox virns against smallpox in 1796. This was followed by Pasteur, who developed a rabies vaccine in 1885. The best-known twentieth-century vaccine is probably the anti-polio vaccine introduced by Salk in 1954. Vaccines exist to prevent diseases caused by either bacteria or viruses. 

Nucleoprotein heteropolar complexes of nucleic acids (in particular, nuclear DNA) with basic, acid-soluble proteins (histones or protamines), and with acidic, base- or detergent-soluble non-histone chromatin proteins. N. occur mainly in the chromatin of the cell nucleus in its quiescent state, and in the chromosomes when the nucleus is active, i.e. dividing. Many viruses consist entirely of N., but N. are absent from bacteria. N. are concerned in DNA replication, and in the control of gene function during protein biosynthesis. 

A membrane in a cell wall fulfills a number of functions. It acts as a barrier to prevent the contents of a cell from dispersing and also to exclude external agents such as viruses. The membrane, however, does not have a purely passive role. It also enables the transport of ions and chemicals such as proteins, sugars, nucleic acids in and out via the membrane proteins. Membranes appear not only in the external cell walls but also within the cell of eukaryotes (plants and animals, but not bacteria), where they subdivide the cell into compartments with different fimctions. A part of cell membrane is illustrated in Figure 9.10. It is built from a bilayer of lipids (usually phospholipids, except for the membranes of the brains, which is... 

Nucleic acid contents of SCP products, which range up to 16% in bacteria and 6—11% in yeasts, must be reduced by processing so that intakes are less than 2 g/d to prevent kidney stone formation or gout. Adverse skin and gastrointestinal reactions have also been encountered as a result of human consumption of some SCP products (87). 

Platinum—polyethyleneimine complexes prevent the division of bacteria, and are being tested as carriers in the treatment of cancer and vimses (445—447). Encapsulated PEIs containing nucleic acid bases activate the neutrophils in human blood (448). 

---