Basic DNA structure Flashcards
(23 cards)
What are the two long DNA strands called?
sugar phosphate backbones.
What are the spiralling strands amazing?
green coloured strands
Where does the nitrogenous bases extend from?
each sugar phosphate backbone, making the ladder steps
What is a base pair?
When nitrogenous base from one sugar phosphate backbone is joined, or bound, to a nitrogenous base on the other sugar phosphate backbone.
Who proposed the double helix model of DNA?
James Watson and Francis Crick in 1953
What bonded bases makes a base pair?
Two nitrogenous bases form a bond between the two DNA strands
What is a helix characterised by?
- Two spiralling sugar phosphate backbones.
- Perpendicular nitrogenous bases bound in base pairs.
What is a double helix made of?
Two sugar phosphate backbones and nitrogenous bases
What is DNA in the shape of?
a double helix
what bases is always paired to the same bases?
the nitrogenous bases
(C) + (G)
Cytosine is always paired with guanine
(A) + (T)
adenine is always paired with thymine
what is the base-pairing rule?
Cytosine is always paired with guanine and adenine is always paired with thymine
what carries instructions for the cell to make proteins?
The sequences of bases within a strand of DNA
What is the sugar phosphate backbone is made up of?
deoxyribose sugar and phosphate
what are the nitrogenous bases bound to?
the deoxyribose sugar
What is a nucleotide?
One phosphate, one deoxyribose sugar and one nitrogenous base
what is DNA made up of?
repeating nucleotides
what are the basic building blocks of DNA
nucleotides
how is one string of DNA formed?
The deoxyribose sugar of one nucleotide will bind to the phosphate of another
how is a double helix formed?
The two strings of nucleotides then bind to one another by their nitrogenous bases
what is the sugar phosphate backbone is made from?
deoxyribose sugar and phosphates
what are the nitrogenous bases bound to?
deoxyribose sugar
