DNA Structure UNfinished

Francis  Crick 

co-discoverer of the 3 dimensional structure of DNA in 1953

DNA

duplicate itself and control the development of the rest of the cell in a specific way

Friedrich Miescher

a Swiss physician and biochemist who described the DNA in the mid-19th century.

Friedrich Miescher

He isolated nuclei from white blood cells in pus on soiled bandages, and he found out that there is an unusual acidic substance containing nitrogen and phosphorus in the nuclei.

Nuclein

was the term called by Miescher in an 1871 paper since the material was discovered in cell nuclei

nucleic acid

nuclein was called then?

Archibald Garrod

an English Physician who was the first one to link inherited disease and protein in 1902.

Archibald Garrod

he noted that people born with certain errors of metabolism lacks certain enzymes.

Frederick Griffith

an English microbiologist who took the first step in identifying DNA as the genetic material.

Frederick Griffith

Through studying pneumonia during the years' post-1918 flu pandemic, he noticed that mice with a certain form of pneumonia harbored one of two types of Streptococcus pneumoniae bacteria.

Type R bacteria

rough in texture

Type  S  bacteria 

smooth since they were enclosed in a polysaccharide capsule.

Frederick Griffith

he suggested that the transforming principle might be some part of the polysaccharide capsule or some compound required for capsule synthesis.

Oswald Avery, Colin MacLeod, and Maclyn McCarty

were U.S. physicians who hypothesized that a nucleic acid might be Griffith’s "transforming principle."

DNA transforms bacteria-and that protein does not.

By adding enzymes that either destroy proteins (protease) or DNA (deoxyribonuclease or DNase) to bacteria that were broken apart to release their contents, they demonstrated that

Protease

an enzyme that dismantles the protein

DNase

an enzyme that dismantles the DNA only.

1944

the year they confirmed that DNA transformed the bacteria.

Alfred Hershey and Martha Chase

U.S. microbiologists who used Escherichia coli bacteria infected with a virus that consisted largely of a protein "head" surrounding DNA in 1953.

Culture medium

a way that researchers can analyze viruses in which the medium. It contains a radioactive chemical that the viruses take up.

Phoebus Levene

Russian-American biochemist  who  identified  the  5-carbon sugar  ribose  as  part  of  some  nucleic acids in 1909.

Phoebus Levene

He discovered deoxyribose in other nucleic acids in 1929.

Phoebus Levene

He also discovered the three parts of a nucleic acid
Sugar
nitrogen-containing base
phosphorus-containing component

Erwin Chargaff

showed that DNA in several species contains equal amounts of the bases adenine (A) and thymine (T) and equal amounts of the bases guanine (G) and cytosine (C).

Maurice Wilkins (English physicist) and Rosalind Franklin (English chemist)

bombarded DNA with X-rays using a technique called X-ray diffraction and then deduced the overall structure of the molecule from the patterns in which the X rays were deflected.

end of January 1953

Wilkins showed photo 51 to Watson at the ___, made the men realize that the  symmetry  of  the  molecule fits the shape of a regular helix.

Linus Pauling

a famed biochemist who suggested a triple helix structure for DNA, but it was incorrect

Watson and Crick

found the answer using cardboard cut outs of the DNA components when Watson was playing with the cutouts while waiting for a meeting with Crick.