9 Chapter 9: DNA Structure, Protein Synthesis and GMO’s (9/16) -- Human Biology

9 Chapter 9: DNA Structure, Protein Synthesis and GMO’s Chapter Outline - 9.1 DNA Structure - 9.2 Basics of DNA Replication - 9.3 DNA Replication in Prokaryotes - 9.4 DNA Replication in Eukaryotes - 9.5 DNA Repair - 9.6 Genetic Code - 9.7 Prokaryotic Transcription - 9.8 Eurkaryotic Transcription - 9.9 RNA Processing in Eukaryotes - 9.10 Ribosomes and Protein Synthesis - 9.11 Regulation of Gene Expression - 9.12 Prokaryotic Gene Regulation - 9.13 Eukaryotic Gene Regulation - 9.14 Eukaryotic Transcription Gene Regulation - 9.15 Eukaryotic Post-Transcriptional Gene Regulation - 9.16 Eukaryotic Translational and Post-Translational Gene Regulation - 9.17 Cancer and Gene Regulation - 9.18 Biotechnology - 9.19 Mapping Genomes - 9.20 Whole-Genome Sequencing - 9.21 Applying Genomics - 9.22 Genomics and Proteomics Figure 9.1 Dolly the sheep was the first large mammal to be cloned. Introduction The three letters “DNA” have now become synonymous with crime solving, paternity testing, human identification, and genetic testing. DNA can be retrieved from hair, blood, or saliva. Each person’s DNA is unique, and it is possible to detect differences between individuals within a species on the basis of these unique features. Whereas each cell shares the same genome and DNA sequence, each cell does not turn on, or express, the same set of genes. Each cell type needs a different set of proteins to perform its function. Therefore, only a small subset of proteins is expressed in a cell. For the proteins to be expressed, the DNA must be transcribed into RNA and the RNA must be translated into protein. In a given cell type, not all genes encoded in the DNA are transcribed into RNA or translated into protein because specific cells in our body have specific functions. Specialized proteins that make up the eye (iris, lens, and cornea) are only expressed in the eye, whereas the specialized proteins in the heart (pacemaker cells, heart muscle, and valves) are only expressed in the heart. At any given time, only a subset of all of the genes encoded by our DNA are expressed and translated into proteins. The expression of specific genes is a highly regulated process with many levels and stages of control. This complexity ensures the proper expression in the proper cell at the proper time. Since the rediscovery of Mendel’s work in 1900, the definition of the gene has progressed from an abstract unit of heredity to a tangible molecular entity capable of replication, expression, and mutation. Genes are composed of DNA and are linearly arranged on chromosomes. Genes specify the sequences of amino acids, which are the building blocks of proteins. In turn, proteins are responsible for orchestrating nearly every function of the cell. Both genes and the proteins they encode are absolutely essential to life as we know it. Learning Objectives You will be able to describe the structure and function of DNA and how it is translated into proteins: - Explain how DNA is copied to carry the info