LEARNING OBJECTIVES In this section, you will explore the following question: Connection for AP® Courses The regulation of gene expression in prokaryotic cells occurs at the transcriptional level. Simply stated, if a cell does not transcribe the DNA’s message into mRNA,…
Figure 16.1 The genetic content of each somatic cell in an organism is the same, but not all genes are expressed in every cell. The control of which genes are expressed dictates whether a cell is (a) an eye cell or (b)…
The Genetic Code The genetic code refers to the DNA alphabet (A, T, C, G), the RNA alphabet (A, U, C, G), and the polypeptide alphabet (20 amino acids). The Central Dogma describes the flow of genetic information in the…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses After the information in the gene has been transcribed to mRNA, it is ready to be translated to polypeptide. The players in translation include the mRNA…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses Scientists discovered a strand of mRNA translated into a sequence of amino acids (polypeptide) shorter than the mRNA molecule transcribed from DNA. Before the information in…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses As expected, transcription in eukaryotes is more complex than transcription in prokaryotes. First, transcription in eukaryotes involves one of three types of RNA polymerase, depending on…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses During transcription, the enzyme RNA polymerase moves along the DNA template, reading nucleotides in a 3′ to 5′ direction, with U pairing with A and C…
LEARNING OBJECTIVES In this section, you will explore the following questions: Connection for AP® Courses Since the rediscovery of Mendel’s work in the 1900s, scientists have learned much about how the genetic blueprints stored in DNA are capable of replication, expression,…
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…