DNA Chapter 12 Sections 1 and 2 only

DNA Chapter 12 Sections 1 and 2 only

• HOW DID WE GET TO THE POINT OF KNOWING THAT THE “SNOT” YOU FOUND DURING THE DNA EXTRACTION LAB WAS ACTUALLY THE MOLECULE RESPONSIBLE FOR CONTROLLING ALL THINGS IN AN ORGANISM? Click on a lesson name to select.

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material Griffith § Performed the first major experiment that led to the discovery of DNA as the genetic material

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material Avery § Identified the molecule that transformed the R strain of bacteria into the S strain § Concluded that when the S cells were killed, DNA was released § R bacteria incorporated this DNA into their cells and changed into S cells.

Chapter 12 Molecular Genetics 12. 1 DNA Hershey and Chase § Used radioactive labeling to trace the DNA and protein § Concluded that the viral DNA was injected into the cell and provided the genetic information needed to produce new viruses

Rosalind Franklin

Watson and Crick Model

The closest we can get with microscopes

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material DNA Structure § Nucleotides § Consist of a five-carbon sugar, a phosphate group, and a nitrogenous base

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material DNA Structure § DNA often is compared to a twisted ladder. § Rails of the ladder are represented by the alternating deoxyribose and phosphate. § The pairs of bases (cytosine–guanine or thymine–adenine) form the steps. We will make a paper model

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material Orientation § On the top rail, the strand is said to be oriented 5′ to 3′. § The strand on the bottom runs in the opposite direction and is oriented 3′ to 5′.

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material Chargaff § Chargaff’s rule (AKA: Base-Pair Rule) C = G and T = A

Coloring the Anatomy of DNA • You and your West partner need to select 6 colors in order to color in your DNA diagram

MAKING A DNA MODEL

Chapter 12 Molecular Genetics 12. 1 DNA: The Genetic Material Chromosome Structure § DNA coils around histones to form nucleosomes, which coil to form chromatin fibers. § The chromatin fibers supercoil to form chromosomes that are visible in the metaphase stage of mitosis.

Chapter 12 Molecular Genetics 12. 2 Replication of DNA Semiconservative Replication § Parental strands of DNA separate, serve as templates, and produce DNA molecules that have one strand of parental DNA and one strand of new DNA. http: //www. youtube. com/watch? feature=endscreen&NR=1&v=8 k. K 2 zwj. RV 0 M – Crash course video on DNA structure and replication

Chapter 12 Molecular Genetics 12. 2 Replication of DNA http: //www. youtube. com/watch? v=AGUu. X 4 PGl. Cc&list=PL 6386303098 2 B 8 C 13 Good Video Showing REPLICATION § DNA helicase, an enzyme, is responsible for unwinding and unzipping the double helix.

Chapter 12 Molecular Genetics 12. 2 Replication of DNA Base pairing http: //www. youtube. com/watch? v=qn-JWM 89 fo watch it here § DNA polymerase adds appropriate nucleotides to the chain by adding to the 3′ end of the new DNA strand.

Chapter 12 Molecular Genetics 12. 2 Replication of DNA § One strand is called the leading strand is elongated as the DNA unwinds. § The other strand of DNA, called the lagging strand, elongates away from the replication fork. § The lagging strand is synthesized discontinuously into small segments, called Okazaki fragments.

Chapter 12 Molecular Genetics 12. 2 Replication of DNA Joining § DNA ligase makes sure all DNA nucleotides are bonded together.

Chapter 12 Molecular Genetics 12. 2 Replication of DNA Comparing DNA Replication in Eukaryotes and Prokaryotes § Eukaryotic DNA unwinds in multiple areas as DNA is replicated. § In prokaryotes, the circular DNA strand is opened at one origin of replication.