3.16B and 3.17B - DNA structure and RNA structure

Edexcel IGCSE Biology

DNA and RNA are polynucleotides

DNA and RNA are polynucleotides

DNA and RNA are polynucleotides

sugars

• DNA = deoxyribose

• RNA = ribose

shape

• DNA = polymer made up of two strands coiled around to make a double helix

• RNA = only made up of one polynucleotide strand, single stranded

bases

• DNA = adenine, thymine, guanine, cytosine

  • complementary base pairing = A and T, G and C

• RNA = adenine, thymine, guanine, uracil

  • contains uracil instead of thymine

length

• DNA is longer, RNA is shorter