DNA Structure Standard 3.1.1 Explain the double-stranded, complimentary nature of DNA as related to its function in the cell.

Discovery of DNA Frederick Griffith’s experiments (~1928) showed that hereditary material can pass from one bacterial cell to another. The transfer of genetic material from one cell to another cell or from one organism to another organism is called transformation.

Discovery of DNA Oswald Avery’s experiments (1944) showed that DNA is the hereditary material that transfers information between bacterial cells. Before this scientists though proteins would code for our traits since they are more diverse.

Discovery of DNA Alfred Hershey and Martha Chase designed a series of experiments to support that DNA, not proteins, is the genetic material.

DNAs Structure Watson and Crick created a model of DNA by using Franklin’s and Wilkins’s DNA diffraction X-rays. 1953

Structure of DNA DNA is made of two nucleotide strands that wrap around each other in the shape of a double helix.

Nucleotide Structure A DNA nucleotide is made of a 5-carbon deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), or thymine (T).

Bonds of DNA Nucleotides along each DNA strand are linked by covalent bonds. Hydrogen bonding between the complementary base pairs, G-C and A-T, holds the two strands of a DNA molecule together.