AP Biology: Unit 6 Exam Latest Update Graded A+

AP Biology: Unit 6 Exam Latest Update Graded A+ 5 end and 3 end -5 end gets a modified nucleotide 5cap - 3 end gets a Poly-A-tail Avery, McCarty and Macleod Announced that the transforming substances was DNA Bacterial transformation Transformation is the process by which foreign DNA is introduced into a cell. Transformation of bacteria with plasmids is important not only for studies in bacteria but also because bacteria are used as the means for both storing and replicating plasmids. Because of this, nearly all plasmids (even those designed for mammalian cell expression) carry both a bacterial origin of replication and an antibiotic resistance gene for use as a selectable marker in bacteria. Components of a virus Small infectious particle that has a nucleic acid, and enclosed in a protein coat and a membranous envelope Elongation Primer sequence is added with complementary RNA nucleotides which are replaced by DNA nucleotides Erwin Chagraff Reported that DNA composition varies from one species to the next -base composition of DNA varies between species -in any species, the numbers of A and T bases are equal and the number of G and C bases are equal Gel electrophoresis Rapidly analyzes and compares genomes. Lab technique used to separate macromolecules primarily DNA and proteins. Gene Expression The process by which DNA directs protein synthesis includes two stages; transcription and translation How do eukaryotic cells modify RNA after transcription? -enzymes in the eukaryotic nucleus modify pre mRNA (RNA processing) before the genetic messages are dispatching to the cytoplasm. -During RNA processing, both ends of the primary transcript are altered How do mutations change the amino acid sequence of a protein? The change of a single nucleotide in a single a DNA template strand can lead to the production of an abnormal protein. Impact of DNA methylation Causes DNA to be more tightly packed and therefore reduces gene expression Impact of histone acetylation Makes chromotin less tightly packed and encourages transcription on gene expression Inducible operon Usually off and a molecule called