Unit 6 topic 1

Rosalind Franklin

Scientist who performed X-Ray Crystallography of DNA in the 1950s, revealing its regular and repetitive pattern.

Chargaff's Rule

The principle stating that in any species, the amount of adenine equals the amount of thymine (A=T), and the amount of cytosine equals the amount of guanine (C=G).

Purines

Nucleotides with a double ring structure; specifically adenine (A) and guanine (G).

Pyrimidines

Nucleotides with a single ring structure; specifically cytosine (C), uracil (U), and thymine (T).

Hydrogen Bonds in DNA

The type of bonds that hold together base pairs in DNA; adenine pairs with thymine using two hydrogen bonds, while cytosine pairs with guanine using three hydrogen bonds.

DNA Structure

DNA is characterized as a double-stranded helix that has antiparallel strands and a backbone made of sugar-phosphate.

Eukaryotic DNA

DNA found in the nucleus with linear chromosomes.

Prokaryotic DNA

DNA located in the nucleoid region with circular chromosomes.

Plasmids

Small, circular DNA molecules found in prokaryotes that replicate independently and may contain genes beneficial in specific environments.

Recombinant Plasmid DNA

A plasmid that has been artificially modified to contain a gene of interest.

Chargaff's Contributions

Discovered that in DNA, the amount of adenine equals thymine and cytosine equals guanine.

Franklin's Contributions

Revealed the helical shape of DNA through X-ray crystallography.

Watson and Crick

Scientists who built the first 3D model of DNA by integrating the work of Franklin and Chargaff.

Key Differences between DNA and RNA

DNA is double-stranded with thymine, while RNA is single-stranded and contains uracil instead of thymine.