Bio

Nucleic acid

Complex bio molecule that stores cellular information in the form of a code.

Double helix

Twisted ladder shape formed by two strands of nucleotides twisted around each other.

Transform

The genetic alteration of a cell by the uptake an incorporation of outside DNA.

What was Frederick Griffiths experiment?

He concluded that a substance can transform bacteria. Rough bacteria showed to change into smooth bacteria.

What was Oswald Avery’s discovery?

He identified the molecule that transformed R strain of S pneumoniae into S strain.

How did R bacteria transform into S bacteria?

When S cells were killed, DNA was released. R bacteria used this DNA in their cells to change into S cells.

What was Alfred Hershey and Martha Chases experiment?

Used radioactive labeling to trace bacteriophage DNA and protein. Concluded that DNA not protein was genetic material in viruses

What did Chargaff do?

Created Chargaffs rule. C=G T=A

What was Rosalind Franklin and Maurice Wilkins experiment?

Used X ray diffraction that showed DNA was double helix.

What was James Watson and Francis Cricks experiment?

They used Franklin and Chargaffs data to measure width of helix and spacing of bases. Built model on data.

What were important features of this model?

Two outside strands of deoxyribose and phosphate

Cytosine and guanine bases pair through 3 hydrogen bonds

Thymine and adenine bases pair through two hydrogen bonds

Nucleotides

Subunits of nucleic acids

Have: phosphate group, 5-carbon sugar, nitrogenous base

Purine bases

Adenine and guanine

Pyrimidine bases

Cytosine thymine and uracil

Base pairing rule

A=T and C=G purine always bind to pyrimidine bases

Top strand orientation

5’ To 3’

Bottom strand orientation

3’ to 5’