The Structure Of DNA And RNA Flashcards
What does DNA consist of
Two polynucleotide strands
-the sugar-phosphate backbone on the outside with the bases in the centre
What are the two polynucleotide strands held together by
Hydrogen bonds which form between the bases on opposite strands of
What is the complimentary strand that always pairs with guanine
Cytosine
What is the complimentary strand that always pairs with cytosine
Guanine
What is the complimentary base that always pairs with adenine
Thymine
What is the complimentary base that always pairs with thymine
Adenine
In complimentary base pairing which two type of base always pair together
Purines and pyrimidines
What happens to the distance between the sugar phosphate backbones due to purines always pairing with pyrimidines
It’s constant all the way down the dna molecule
Are the two polynucleotide strands parallel
No they’re anti parallel( they run in opposite directions)
How many hydrogen bonds are formed between guanine and cytosine
Three
How many hydrogen bonds are formed between adenine and thymine
Two
How can we calculate the proportions of the different nucleotides
Because of complimentary base pairing
-the proportions of guanine and cytosine are always the same
-the proportions of adenine and thymine are always the same
What do the two polynucleotide strands in DNA twist around each other to form
A double helix
Where is DNA found
In the chromosomes in the nucleus
Where is RNA found
In the cytoplasm
