2.1.3 - nucleotides and nucleic acids Flashcards
why are nucleic acids important
important for storage and transfer of genetic information to make proteins
what elements are nucleic acids made up of
C, H, O, N, P
what is the structure of a nucleic acid
contains a phosphate, a pentose sugar and a nitrogenous base
what are the 2 types of nucleic acids
DNA and RNA
what are the 5 nitrogenous bases
adenine, guanine, thymine, cytosine and uracil
what are the purine bases
adenine and guanine
how many carbon rings do the purine bases contain
2
what are the pyrimidine bases
thymine, cytosine and uracil
how many carbon rings does a pyrimidine base contain
1
what is the pentose sugar called in DNA
deoxyribose
what is the pentose sugar called in RNA
ribose
what bases are found in RNA
A, U, C, G
what is the bond between 2 nucleotides called
phosphodiester bond
how is a phosphodiester bond formed
between the hydroxyl group on C3 of one nucleotide and the phosphate on C5 of another nucleotide
what is released when a phosphodiester bond is formed
water
what kind of reaction is the formation of a phosphodiester bond
condensation
how many hydrogen bonds do adenine and thymine form
2
how many hydrogen bonds do guanine and cytosine form
3
where is DNA found in the cell
the chromosomes in the nucleus
where is the RNA found in the cell
in the cytplasm
how many polynucleotide strands are in DNA
2
how many polynucleotide strands are in RNA
1
what is the structure of ATP
ribose sugar, adenine base and 3 phosphate groups
what part of ATP is called adenosine
the ribose sugar and the adenine
how does ATP become ADP
a small amount of energy and a water molecule is needed to break the covalent bond that holds the last phosphate group (hydrolysis)
what does ATP do
acts as an immediate source of energy
what happens during conservative replication
one molecule of DNA contains 2 new strands and one molecule of DNA contains the original strands
is DNA replication conservative or semi-conservative
semi-conservative
what happens in the first stage of DNA replication
enzyme DNA helicase attaches to the DNA molecule and breaks the hydrogen bonds between the complementary and causes the 2 polynucleotide strands to separate
what happens after the 2 polynucleotide strands are split up
free nucleotides line up with their complementary bases and are held together by hydrogen bonds and there are no phosphodiester bonds
what happens after the free nucleotides have lined up with their complementary bases
DNA polymerase moves down the molecule and catalyses the formation of phosphodiester bonds between the free nucleotides
