3. Genetics: DNA Flashcards
What is the structure of DNA
Made up if polymers - repeating units - nucleotides
Nucleotide consists of one sugar molecule, one phosphate molecule and one base
Sugar and phosphate molecules in nucleotides - from backbone to DN strands - molecules alternate
One of four different bases join to each sugar :
A (adenine) T (thymine) C (cytosine) G (guanine)
DNA molecule - two strands coiled together - double helix
A always pairs with T and C always pairs with G - complementary base pairing - held by hydrogen bonds
How is DNA stored
Stored as chromosomes - long, coiled up molecules of DNA - found in nucleus it eukaryotic cells
Gene = section of DNA on a chromosome that codes for a particular protein - sequence of bases in gene determines what protein is produced
All of an organisms DNA makes up its genome
