Structure of DNA Flashcards
What is the name for the repeating units that make up a strand of DNA?
Nucleotides
What is a nucleotide made from?
deoxyribose sugar, base, phosphate
Which end of the DNA strand is called the 3’ end?
End with deoxyribose sugar
Which end of the DNA strand is called the 5’ end?
End with phosphate
Which shape is a DNA molecule?
Double helix
What is the complementary base pairing rule?
Adenine and Thymine always pair, Guanine and Cytosine always pair
What bonds hold the complementary base pairs together?
Hydrogen bonds
Which bonds hold the deoxyribose sugar of one nucleotide to the phosphate of another?
Strong chemical bonds (covalent bonds)
Why are DNA strands described as anti-parallel?
One strand runs in the 3’ -> 5’ direction and the other runs in the 5’ -> 3’ direction.
Where do you find DNA in a eukaryote?
In the nucleus, in the mitochondria, in the chloroplast (also plasmids in yeast).
How is DNA stored in prokaryotes?
As a large circular chromosome and in plasmids.
What is a plasmid?
A small ring of DNA.
How is DNA stored in eukaryotes?
Linear chromosomes in the nucleus, small circular chromosomes in the mitochondria and chloroplast.
How is DNA packaged within the nucleus of eukaryotes?
Tightly wound around proteins to form chromosomes.
