分子生物学（双语）2 Genes Code for Proteins.ppt

Chapter 2 Genes Code for Proteins FIGURE CO: Genes Code for Proteins Reprinted from Cell, vol. 136, F. Brandt, et al., The Native 3D Organization of Bacterial Polysomes, pp. 261-271, Copyright (2009), with permission from Elsevier [/science/journal. Photo courtesy of Wolfgang Baumeiste FIGURE 01: Each chromosome has a single long molecule of DNA within which are the sequences of individual genes FIGURE 02: Genes code for proteins; dominance is explained by the properties of mutant proteins FIGURE 03: The cistron is defined by the complementation test FIGURE 04: Mutations that do not affect protein sequence or function are silent FIGURE 05: The w locus has an extensive series of alleles whose phenotypes extend from wild-type (red) color to complete lack of pigment FIGURE 06: The ABO blood group locus codes for a galactosyltransferase whose specificity determines the blood group FIGURE 07: Chiasma formation is responsible for generating recombinants FIGURE 08: Recombination involves pairing between complementary strands of the two parental duplex DNAs FIGURE 09: Recombination between genes depends on their distance apart FIGURE 10: Frameshift mutations show that the genetic code is read in triplets from a fixed starting point FIGURE 11: An open reading frame starts with AUG and continues in triplets to a termination codon FIGURE 12: The recombination map of the tryptophan synthetase gene corresponds with the amino acid sequence of the protein FIGURE 13: RNA is synthesized by using one strand of DNA as a template for complementary base pairing FIGURE 14: The gene may be longer than the sequence coding for protein FIGURE 15: Transcription and translation take place in the same compartment in bacteria FIGURE 16: Gene expression is a multistage process FIGURE 17: Control sites in DNA provide binding sites for proteins; coding regions are expressed via the synthesis of RNA FIGURE 18: A cis-acting site controls expression of the adjacent DNA but does not influence