Nucleic acids Flashcards
What is step 2 of DNA replication.
Hydrogen bonds are broken by DNA helicase.
What is step 3 of DNA replication?
Free nucleotides are bonded to the exposed bases following the complementary base pairing rules.
What is step 4 of DNA replication.
Each of the new DNA molecules contain one old strand and one new stand this is semi- conservative replication.
Step one of DNA replication.
DNA unwinds using gryase enzymes.
What is the difference between DNA and RNA?
In RNA
The sugar molecule in each nucleotide is ribose.
The base thymine is replaced by uracil.
The polynucleotide chain is single standard and shorter.
What is the structure of a single nucleotide?
Phosphate, deoxyribose and a nitrogenous base.
Where are the hydrogen bonds in DNA?
Between the nitrogenous base pairs.
How many bonds between adenine and thymine?
2
How many bonds between guanine and cytosine?
3
How is DNA organised in eukaryotic cells?
Tightly wound around histone proteins into chromosomes.
Difference between purines and pyrimidines?
Purine has two rings and pyrimidines has one ring.
Why are DNA strands described as antiparallel
As the strands run in opposite directions.
