Flashcards in Nucleic Acids and Chromosomes Deck (23):
What is a nucleoside?
Sugar and base with no phosphate
What are names of the natural nucleosides?
Adenosine, guanosine, cytidine, uridine, thymidine
Which are the purines?
Adenine and guanine
Which are the pyrimidines?
Cytosine, thymine and uracil
Whats the difference between a pyrimidine and purine?
1 ring in a pyrimidine vs 2 rings in a purine
Which prime carbon attaches to the base?
Which prime carbon attaches to the phosphate?
What is the bind formed between the phosphate and hydroxyl group?
How are sugars and phosphates linked in nucleotides (not bond wise)?
The 3’-OH of sugar of one nucleotide is linked to phosphate group, which in turn is joined to 5’-OH of adjacent sugar
The first nucleotide in a sequence has a free....
The last nucleotide in a sequence has a free...
....3' hydroxyl group
How are DNA sequences read directionally?
5' to 3'
Which grooves are the major interactions with DNA madE?
How many bp per helical turn?
How wide is DNA?
What conditions melt/denature DNA?
Low salt/high heat
What conditions anneal/hybridise DNA?
High salt/low heat
What is a karyotype?
Organised profile of someone's chromosomes
What is DNA wrapped around? What does this form?
Proteins known as histones, forms chromatin.
What is the lowest level of DNA packaging called?
How many bp per nucleosome?
Why do histones interact well with DNA?
Histones are positive and the negative phosphate backbone gives an attraction between the two