Introduction

Figure 15.1 Genes, which are carried on (a) chromosomes, are linearly organized instructions for making the RNA and protein molecules that are necessary for all of processes of life. The (b) interleukin-2 protein and (c) alpha-2u-globulin protein are just two examples of the array of different molecular structures that are encoded by genes. (credit “chromosome: National Human Genome Research Institute; credit “interleukin-2”: Ramin Herati/Created from PDB 1M47 and rendered with Pymol; credit “alpha-2u-globulin”: Darren Logan/rendered with AISMIG)

Chapter Outline

15.1 The Genetic Code

15.2 Prokaryotic Transcription

15.3 Eukaryotic Transcription

15.4 RNA Processing in Eukaryotes

15.5 Ribosomes and Protein Synthesis

The definition of gene has progressed from being an abstract unit of heredity in Mendel’s time to our current concept of a tangible molecular entity capable of replication, expression, and mutation (Figure 15.1). Currently, we can perform tests for many genetic diseases, but these tests create ethical and legal issues. For example, would you want to be tested for a debilitating genetic disease if there was the possibility insurance companies could use that information to deny you coverage? Fortunately, the Genetic Information Nondiscrimination Act of 2008 protects American citizens from discrimination from both insurance companies and employers based on genetic information.