ANTHROP 2E03 Lecture Notes - Lecture 3: Francis Crick, Genetic Drift, Nuclear Membrane
4 Feb 2018
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Document Summary
Dna as a molecule has been recognized since darwin"s time. It wasn"t until francis crick demonstrated structure of dna. Structure of dna deciphered in 1953 by francis crick, james watson, and rosalind. 4 nitrogenous bases: purines - adenine (a) and guanine (g, pyrimidines - thymine (t) and cytosine (c, deoxyribose sugar and phosphate backbone, nucleotide = sugar, phosphate, base. When they get incorporated, it moves those phosphates and retains one and becomes part. Nitrogenous bases can form hydrogen bonds with one another. Adenine forms two hydrogen bonds with thymine. Guanine forms three hydrogen bonds with cytosine. Dna is a polymer made of deoxynucleotides. Hydrogen bonding of nitrogenous bases causes dna to form a double helix. The two strands are complementary and antiparallel. Dna is the only nucleic acid present in some molecules or organisms, such as viruses. Rna is also vital in important cell functions, such as transcription and translation.
