DNA structure Flashcards
DNA is made up of 4 types of macromolecules
known as nucleic acid, polysaccharides, lipids, and protein.
DNA stands for..
deoxyribonucleic acid
DNA must be able to…
- carry genetic info for one generation to the next.
- be easily and accurately copied before cell division.
explain nucleotides
DNA molecule is made of building blocks known as nucleotides.
what does DNA nucleotide consist of. (and diagram)
- a 5-carbon sugar (deoxyribose)
- a phosphate group
- one of 4 possible nitrogenous bases
who analysed DNA to find its components?
Phoebus Levene. in 1929, he said that DNA consist of deoxyribose sugar, nitrogenous bases, and phosphorus.
2 types of nitrogenous bases.
pyrimidines: cytosine, thymine (1 ring)
purines: guanine and adenine (2 rings).
what are the 4 nucleotides link together by?
sugar and phosphate groups to form chains, which vary in length and sequence of the nitrogenous bases.
(sugar phosphate backbone)
what provides genetic code.
sequence of nitrogenous bases. and also decides production of protein.
what bases match and what are they called
adenine = thymine
guanine= cytosine
these are called complementary base pairs.
how is DNA charged, and what is helix.
DNA is negatively charged and two strands of DNA twist around each other to form a double helix.
DNA has an orientation based on the numbering of carbons in the sugar molecule which is
5’ (5 prime) end
3’ end
what binds to what, on a DNA structure
*phosphate on 5’ end binds on to 3’ on the DNA nucleotide in front of it
why is DNA called anti-parallel?
two strands of DNA are oriented in opposite directions.
what is length of DNA measured in?
base pairs bp
