Chapter 6: DNA and Biotechnology

• DNA can be denatured by conditions that disrupt hydrogen bonding and base-pairing.
• Commonly used to dentare DNA: heat, pH, and chemicals
• Once Denatured DNA is single-stranded.
• Euchromatin contains genetically active DNA.
• Heterochromatin is transcriptionally silent.
• Centromeres are a region of DNA found in the center of chromosomes.
• Centromeres are sometimes referred to sites of constriction because they form noticeable indentions.
• In replication, DNA unwinds at points called origins of replications.
• Replication forks form on both sides of the origin, which increases the efficiency of replication.
• Helicase unwinds DNA, generating two single-stranded template strands.
• Nucleases are responsible for the degradation of DNA
• Topoisomerases reduce torsional stress and reduce the risk of strand breakage.
• DNA polymerases are responsible for reading the DNA template, and synthesizing the new daughter strand.
• DNA polymerase reads the template strand in the 3' to 5' direction.
• DNA synthesizes a complementary strand in the 5' to 3' direction.
• Primase synthesizes a short primer in the 5' to 3' direction to start replication on each strand.
• DNA ligase seals the ends of DNA molecules together, creating one continuous strand of DNA.
• Metastasis is the migration to distant tissues by the bloodstream or lymphatic system.
• Mismatch repair is in the G2 phase of the cell cycle.
• cDNA lacks noncoding regions
• Noncoding regions are introns
• Coding regions are exons
• Hybridization is the joining of complementary base pair sequences.