3.3 DNA Structure Flashcards
State the names of the four bases in DNA
Adenine - thymine
Guanine - cytosine
What are nucleotides composed of?
Phosphate group, sugar; deoxyribose, nitrogen base.
Outline how DNA nucleotides are linked together by covalent bonds into a single strand.
Phosphate group covalently bonded to sugar at four phosphate group below covalently binds to sugar at three C covalent bonds between sugar and nitrogen base
Explain how DNA double helix is formed using complementary base pairing and hydrogen bonds.
A & T held together by 2 hydrogen bonds.
C & G are held by three hydrogen bonds.
A & G are twice the size of T & C there for complementary base pairing is the only arrangement that gives the consistent distance from one strand across the other.
On a double helix to size the ladder made up the phosphates and die ox sugars. The rungs of the ladder are made up the nitrogen bases to bases are complementary paired to each other
