DNA Flashcards
(3 cards)
DNA:
DNA molecule has two strands coiled together in the shape of a double helix.
Two strands held together by chemicals called bases.
There are 4 different bases: adenine, thymine, guanine, cytosine.
Bases are paired, always pair in the same way.
Always adenine/thymine and cytosine/guanine. This is called base pairing.
The base pairs joined together by weak hydrogen bonds.
A gene is a section of DNA, and the sequence of bases in a gene code for a specific protein.
DNA
A double helix of paired bases
Who discovered DNA:
Rosalind Franklin and Maurice Wilkins worked out that DNA had a helical structure by directing beams of x-rays onto crystallised DNA and looking at the patterns the x-rays formed as they bounced off.
James Watson and Franklin Crick used knowledge that the amount of adenine + guanine matched the amount of thymine + cytosine to make a model of the DNA molecule where all the pieces fitted together.
