DNA Replication - Structure - Replication chapter 8.1 to 8.3 in text And 8.4, 8.5, 8.7

Nucleic Acids Polymers of 4 nucleotides Uses: Information transfer from cell generation to generation (DNA) and from genome to protein (RNA) DNA replication (making sure that all cells get the same information), Transcription (DNA sequence directing RNA sequence), and Translation (RNA directing amino acid sequence in proteins). (What do you recall about nucleic acid structure?)

Note: - nucleotides have three parts, which are ribose, phosphate group, nitrogenous base - 3 differences between DNA and RNA… ←ribose carbons are numbered 1’ to 5’ - Structure

original.britannica.com/eb/art /The-hum... Note: -complementary base pairing -held together by hydrogen bonds, -to form the double helix. -Chains run in opposite directions: antiparallel ← phosphodiester linkage is between one 5’C and the previous 3’C NB covalent bonds here ←

When it comes time for cell division, the DNA will be further supercoiled or “crunched”… ← Double helix ← Nucleosomes: DNA wrapped around proteins called histones ← Chromatin fiber What is the relationship between DNA, chromosomes, and genes?

- Replication Why would DNA have to be replicated? (Note - answer isn’t written here.) Process: Helix “unzips”. DNA nucleotides brought in and plugged in to form proper pairing. Result of this semi conservative replication is two identical strands, each composed of one old and one new strand.

Less detail, more realistic YouTube videos: This is the first we watched, including packaging and replication. This is the one with the amoeba sisters: a bit light hearted, but still useful. This is the one that works as a recap: The narration was missing....

a quick summary… in French DNA polymerase replication fork template strand 3’ to 5’

DNA replication in prokaryotes The differences between eukaryotic and prokaryotic DNA: - Prokaryotes have a lone loop of double-stranded DNA. - It is not packaged in nucleosomes. - Bacteria may have plasmids – independent DNA loops. Comparing the replication processes: - Cell division is organism’s reproduction: binary fission Recall: Not mitosis, because…? - Enzymes are similar to those in eukaryotes: - Still antiparallel, but - One origin of replication ….

Outline DNA replication, using a labeled sketch. What is the job of RNA polymerase? tRNA? DNA’s 3’ hydroxyl? What is the role of complementary base pairing in replication? (and later in transcription, and in translation?)

Benchmark SC.912.L.16.3 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic information.

Enduring Understandings Essential Questions Why is the sequence of nucleotides in DNA molecules so important? How do changes in the genetic code occur? [I think they mean a given gene sequence, not the actual code…] - The information passed from parents to offspring is coded in DNA molecules. - An altered gene may be passed on to every cell that develops from it.

structure (previous)structure (new)replication nucleotidescomplementary base pairingDNA replication ribosedouble helixorigin of replication phosphate groupantiparallelreplication fork nitrogenous basesemi conservativetemplate strand adenineplasmid3’ to 5’ cytosinebinary fissionhelicase guaninehistonesingle strand binding protein thyminenucleosomeprimase uracilRNA primer DNADNA polymerase RNAligase Okazaki fragment leading strand lagging strand