BIO 121 Chapter 17: Chapter 17- Gene Expression (Transcription and Translation) .docx
Document Summary
Chapter 17: gene expression (transcription and translation: gene expression: process by which genes direct protein synthesis. Proteins are the link between genotype and phenotype proteins are how. Genes: long strands of dna; polypeptides: long strands of amino acids. Dna-rna-protein information. mrna is translated into an amino acid sequence. information in the dna. 4 cubed: rna is complementary to the dna template strand it"s copying. Most rna transcripts have long noncoding stretches of nucleotides. Introns: the noncoding, intervening segments of an rna molecule. Introns function as ribozymes and catalyze its own excision from the rna transcript. Introns provide more terrain for crossovers without interrupting coding sequences allowing for variation. Exons: the sections that are eventually expressed through coding. So rna polymerase ii transcribes both introns and exons from the dna, but the mrna molecule that enters the cytoplasm is an abridged version.
