Structure of DNA Flashcards
U2L1
What’s the key difference between the structure of DNA and RNA?
DNA has an oxygen molecule bonded to the 2’ carbon whilst RNA has an OH group bonded to the 2’ carbon.
Why is it called an anti-parallel double helix?
The two strands in DNA wrap around each other. It is called anti-parallel because one strand runs in the 3’-5’ direction while another strand runs in the 5’-3’ direction.
How do the nucleotides bond together?
They bond through Phosphodiester bonds (condensation reactions).
How do the two strands bond together which makes up DNA?
They bond via Hydrogen bonds.
The interactions between the
two Nitrogenous Bases on the two different strands bond which cause the two strands to come together and twist around eachother like a ladder.
Why is Gregor Mendel important?
Gregor Mendel proved using pea plants that was likely linked to dominant and recessive genes on alleles. He used this by using probability (which is why Punnett Squares exist).
Mendel was NOT the one to discover the structure of DNA.
Why is Friedrich Miescher important?
He isolated a thick white substance (pause) from the nucleus of white blood cells.
He determined it to be acidic and contain nitrogen and phosphorous.
He named it Nuclein.
Why is Griffith important?
He determined by injecting Rats with lethal and non-lethal strains of TB, that DNA can be transferred in a process called ‘Transformation’.
What did Hershey and Chase discover?
DNA is transferred from viruses to bacteria
The virus protein is not transferred to bacteria
DNA carries the info for making bacteriophage virus
DNA is the hereditary molecule!
What are the four Nitrogenous bases?
Adenine Guanine Cytosine and Thymine
Which of the four Nitrogenous are Purines and Pyrimidines?
Adenine and Guanine are Purines (fused together)
Thymine, Cytosine and Uracil are Pyrimidines (6-membered ring).
Why is Rosalind Franklin important?
She took an X-ray of DNA which revealed that DNA has a helical structure.
Why is Watson and Crick important?
Although they didn’t do their own experiments on DNA, they were the first to propose an anti-parallel double helix model of DNA, that was consistent with all previous observations.
