2A nucleic acids

• Guanine (G) always pairs with cytosine (C) through three hydrogen bonds in DNA.
• Adenine (A) always pairs with thymine (T) through two hydrogen bonds in DNA.
• Each base on one strand pairs with its complementary base on the opposite strand through hydrogen bonds.
• DNA and RNA have many similarities. Both are made up of long strands (polymer) of a repeating unit (monomer) made from a sugar and a phosphate group, each with a nitrogenous base sticking out to the side
• The main difference between DNA and RNA is that DNA contains deoxyribose as the sugar component while RNA contains ribose.
• In DNA, the bases are adenine, guanine, cytosine and thymine; whereas in RNA they are adenine, guanine, uracil and cytosine.
• Thymine replaces uracil in DNA because uracil is unstable when exposed to UV light.
• RNA has a single-stranded structure, unlike DNA which is be double stranded.
• RNA molecules are shorter than DNA molecules due to their single-stranded nature.
• In DNA, the monomers (building blocks) are known as nucleotides.
• Each nucleotide is made up of three components: a sugar, a phosphate group and a nitrogenous base.
• The types of RNA include: Messengers RNA (mRNA), Ribiosomal RNA (rRNA), Transfer RNA (tRNA).
• Nitrogenous bases pair together through hydrogen bonds between complementary pairs.
• Polymer


  A large molecule made up of many repeating subunits, called monomers
• Monomer


  A small molecule that can be joined together with other monomers to form a polymer