Chromosomal Landscapes Refer to Figure 1-7 from Introduction to Genetic Analysis, Griffiths et al., 2012.

Human Chromosomal Landscapes Refer to Figure 1-8 from Introduction to Genetic Analysis, Griffiths et al., 2012.

Molecular Basis for Relationship between Genotype and Phenotype DNA RNA protein genotype function organism phenotype DNA sequence amino acid sequence transcription translation replication

Replication of DNA is semiconservative. Each strand serves as a template. The two strands separate from each other when hydrogen bonds are broken. New strands are synthesized by the addition of nucleotides with bases complementary to those of the template. DNA replication is discontinuous. Two identical double helices result. Replication of DNA is semiconservative. Each strand serves as a template. The two strands separate from each other when hydrogen bonds are broken. New strands are synthesized by the addition of nucleotides with bases complementary to those of the template. DNA replication is discontinuous. Two identical double helices result. Refer to Figure 7-11 from Introduction to Genetic Analysis, Griffiths et al., 2012.

Refer to Figure 7-12 from Introduction to Genetic Analysis, Griffiths et al., 2012.

DNA polymerization requires DNA polymerase. Refer to Figure 7-15 from Introduction to Genetic Analysis, Griffiths et al., 2012.

DNA Polymerases At least 5 DNA polymerases are known in E. coli. DNA polymerase I (pol I): adds nucleotides in 5’ to 3’ direction adds nucleotides in 5’ to 3’ direction removes mismatched based in 3’ to 5’ direction removes mismatched based in 3’ to 5’ direction degrades double-stranded DNA in 5’ to 3’ direction degrades double-stranded DNA in 5’ to 3’ direction DNA polymerase II (pol II): repairs interstrand cross-links repairs interstrand cross-links DNA polymerase III (pol III): catalyzes DNA synthesis at replication fork in catalyzes DNA synthesis at replication fork in 5’ to 3’ direction and only adds nucleotides at 3’ end of growing strand

Overview of DNA Synthesis DNA polymerases synthesize new strands in 5’ to 3’ direction. Primase makes RNA primer. Lagging strand DNA consists of Okazaki fragments. In E. coli, pol I fills in gaps in the lagging strand and removes RNA primer. Fragments are joined by DNA ligase.