Description
My AP Biology Thoughts Unit 6 Gene Expression and RegulationWelcome to My AP Biology Thoughts podcast, my name is Morgan and I am your host for episode # 106 called Unit 6 Gene Expression and Regulation: DNA Replication. Today we will be discussing the process by which cells replicate their DNA
Segment 1: Introduction to DNA Replication Difference between prokaryotic and Eukaryotic DNAP is one circular piece of dna where eukaryotic are multiple linear chromosomesDNA replication is semi-conservativeDouble helix is split in two and then each new strand is synthesized so to new double helices are made, each with one old and one new strand very complex but very fastExtremely accurate (only 1 in a billion bases are messed up)Have to prime the DNA for replicationPrimers are short molecules that attach to the dna at the origin of replication Mde by the enzyme primaseHelicase is the enzyme that unwinds the double helix- initiates the replication fork (where two strands split apart)Multiple replication forks in eukaryotic dnaTopoisomerase checks problems in the DNA before replication and maintains the structureDNA polymerase is the enzyme that synthesizes the new DNA strand- reads the bases and matches up complementary nucleotides
Segment 2: More About the process of replication Replication initiation can occur at both directions from the origin where the primer bindsDNA polymerase can only add nucleotides in the 5 to 3 prime direction, and read the strand of dna in the 3 to 5 prime directionLeading strand is continuousLagging strand is discontinuous, has to read and synthesize in short segments (okazaki fragments)Enzyme ligase seals together the fragmentsEnergy needed for this process (remember forming bonds between the nucleotides requires energy)
Segment 3: Connection to the Course Connection to mitosisS phase of mitosis is dna replicationNecessary for cell division to make the same amount of chromosomes in...