DNA Flashcards
who discovered DNA in 1953?
James Watson and Francis Crick (officially)
Rosalind Franklin
what did Watson and Crick do?
interpreted the x-ray diffraction patterns produced by Rosalind Franklin to propose a model for the molecule of life
what does DNA stand for?
Deoxyribose Nucleic Acid
what was their model called?
helical model
what is DNA?
molecule of heredity
what’s the formula for DNA?
Belongs to pentose sugar C5H10O5
deoxyribose means O4
what’s the structure of DNA?
It is a long macromolecule of polymer consisting of two helical chains coiled around a common axis.
The monomers of these chains are nucleotides
describe the nucleotides
of a 5-carbon sugar a phosphate group and a nitrogen containing organic base
what are the organic bases called?
Adenine, Guanine, Thymine, Cytosine
describe the properties of each base
Adenine and Guanine are the larger bases, described as PURINES.
Thymine and Cytosine are the two smaller bases, described as PYRIMDINES.
whats a purine?
it has two rings
whats a pyrimidine?
made of 1 ring- when we pair them we get 3 rings meeting in the middle.
e.g. Thymine is a pyrimidine base- a single nitrogen containing ring is part of its structure
what’s the position of a chromosome called?
locus
what’s a gene?
short section of DNA that codes for a protein – has a specific locus on a chromosome
what’s a recessive gene?
non-functioning protein (doesn’t do its job) e.g. cystic fibrosis
what’s a dominant gene?
functioning protein (always does its job) e.g. Huntington’s disease