Nucleic Acids, Genes and Proteins

Cells are the basic units for all living organisms. All cells are bounded by a membrane, and bacterial and plant cells have a cell wall. The membrane protects the cell from the outside environment. It consists of a lipid bilayer (Fig. A2.1). The function of the membrane is to control materials that enter and exit the cell and enable biochemical reactions to take place within the cell. 

Simple single-cell organisms, such as bacteria and blue-green algae, are called prokaryotes (see Fig. A2.2). Prokaryotes do not have a well-defined nucleus. 

The genetic material, deoxyribonucleic acid (DNA), is concentrated in the nuclear region. DNA controls the functions of the cell. Ribosomes, granular 

Drugs From Discovery to Approval, Second Edition, By Rick Ng Copyright 2009 John Wiley Sons, Inc. 

Prokaryote cells divide and grow into two daughter cells. In the division process, the DNA replicates and each daughter cell receives one copy. 

1 Cells A2.2 Nucleic Acids A2.3 Genes and Proteins A2.4 Further Reading 

Appendix 2 Cells, Nucleic Acids, Genes and Proteins 

The genetic material, deoxyribonucleic acid (DNA), is concentrated in the nuclear region. DNA controls the functions of the cell. Ribosomes, granular structures that consist of ribonucleic acid (RNA) and proteins, are distributed in the cytosol (soluble part of the cell excluding the nuclear region). 

Within the cell membrane is the cytoplasm. This is where many biochemical reactions take place. The most important structure within the human cell is the nucleus. It is bounded by a nuclear membrane and is separated from other organelles (non-cellular structures in a cell that serve specific functions) in the cytoplasm. 

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Since the emphasis in this chapter is on proteins, peptides, and enzymes, the discu.ssion of biotechnology processes and products is limited to these topics. The various biotechnol-ogy-derived products include enzymes, receptors, hormones and growth factors, cytokines, vaccines, monoclonal antibodies, and nucleic acids (genes and antisense RNA). 

Nucleic acid structures and sequences primary and secondary structure of DNA fragments, translocation of genes between two chromosomes, detection of nucleic acid hybridization, formation of hairpin structures (see Box 9.4), interaction with drugs, DNA triple helix, DNA-protein interaction, automated DNA sequencing, etc. 

Fig. 18.3. Raman spectral analysis of foetal osteoblast (FOB) differentiation. Unsupervised PCA of FOB cells cultured for 3 days in bioactive glass (BG) conditioned media (triangle) or control media (circle) (a). BG-treated cells formed a distinct cluster separate from control cells after 3 days culture. Least square (LS) analysis (which decomposes the cell spectra into the linear combination of Raman spectra obtained from the pure chemical constituents of the cell, e.g. nucleic acid, proteins, lipids, phospholipids and carbohydrates) of the relative RNA concentration of FOBs cultured for 1, 3 and 14 days in culture media (black) or BG condition media (grey), revealed a significantly reduced relative RNA concentration in FOBs culture in BG-conditioned media (b). FOBs cultured in BG-conditioned media appeared to accelerate FOB differentiation into mature adult osteoblast phenotypes (parallel gene and protein expression experiments confirmed this). Significant difference to control (p <0.05) [38]...

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