BI SC 002 Lecture Notes - Lecture 10: Dna Replication, Primase, Helicase

• School: PSU
• Department: Biological Science
• Course: BI SC 002
• Professor: Louise Mc Gibbon

Document Summary

Dna replication: adds in new, complementary nucleotides to the new strand, produces 2 new identical copies of the original dna double helix, semi-conservative. Is the process of making messenger rna (mrna) from the dna of one particular gene. What"s the point: the cell can turn this message into a protein. Using an enzyme known as rna polymerase, genetic information in dna is converted, or transcribed , into rna. Different sugar: ribose instead of deoxyribose. One different base: atgc vs. augc. Multiple functions: carries protein-encoding info, helps make proteins, catalyzes some reactions. The process has 3 steps: initiation, elongation, termination. Elongation: rna polymerase moves along the template strand, making the new rna molecule, the rna molecule is complementary to the dna template strand. Termination: rna polymerase reaches the terminator, which is the end of the gene, the new rna molecule, the dna and the rna polymerase separate, dna becomes a double helix again. The end product of transcription is rna.