DNA Flashcards
who took diffraaction x-ray photographs of DNA crystals
Rosalind Franklin
Who built the first model of DNA using Franklin’s models and when
Watson and Crick; 1950s
DNA is composed of a collection of
nucleotides
DNA have two strands coiled called
double helix
parts of nucleotides
deoxyribose sugar bonded to phosphate group, nitrogenic bases
what kind of bond in the deoxyribose and phosphate bond
phosphodiester bond
“Rungs of ladder”
nitrogenous bases
legs of ladder
phosphate and sugar backbone
most DNA has a ____ hand twist
right-hand twist
how many base pairs does a DNA have in every complete turn
10 base pairs
Meaning of DNA
deoxyribonucleic acid
DNA is made up of subunits known as
nucleotides
What is nucleotide made of
phosphate group
5-carbon sugar
nitrogeous base
why is DNA called anti-parallel strand?
one strand 5’ to 3’ while the other is 3’ to 5’ (going opposite in directon)
Two types of nitrogenous bases are
purine and pyrimidine
what are in purine
adenine
guanine
how many rings does a purine have
double ring
what are thepyrimidines
thymine
cytosine
how many ring do pyrimidines have
single ring
What are the base pairings
adenine thymine
guanine and cytosine
how many hydrogen bonds are needed to bond guanine and cytosine
3 H bonds
how many hydrogen bonds are required to bond adenine and thymine
2 H bonds
