DNA + REPLICATION Flashcards
What is a phosphodiester bond? (1)
the covalent bond between two nucleotides.
what are the pyrimidines of RNA? (2)
-cytosine
-uracil
what are the purines? (2)
-adenine
-guanine
what is the structure of a purine? (1)
double ringed
what is a nucleotide? (1)
the monomer from which nucleic acids are formed.
what is the structure of a pyrimidine? (1)
single ringed.
what are the nitrogenous bases? (2)
-purine
-pyrimidine
what pentose sugar is found in DNA? (1)
deoxyribose
what pentose sugar is found in RNA? (1)
ribose
what does a nucleotide consist of? (3)
-nitrogenous bases
-pentose sugar
-a phosphoric acid
what are the pyrimidines in DNA? (2)
-cytosine
-thymine
what is semi-conservative replication? (2)
the process by which two copies of a DNA molecule are made and in which both ‘parent’ strands remain intact and act as templates for the formation of new complementary strands.
what bases fit together? (2)
-cytosine and guanine
-adenine and thymine (uracil)
why is complementary base pairing important? (3)
-the stability of the double helix (hydrogen bonds are strong when there are many of them)
-the way in which genetic information can be transferred from DNA to RNA (mRNA)
-the way amino acids are assembled into polypeptides in the cytoplasm.
what is the 1st stage of DNA replication? (1)
DNA molecule unwinds and unzips (by DNA helicase) when the hydrogen bonds break. the bases on both strands are exposed.