Biology: DNA and genes

• DNA is made up of a pentose sugar, a phosphate group and an organic base
• the organic bases are adenine guanine cytosine thymine and uracil
• DNA is double stranded deoxyribose nucleotides linked through a condensation reaction
• bases form hydrogen bonds hold strands together and forms a double helix
• transcription reads DNA sequence and produces mRNA
• translation reads mRNA sequence and produces proteins
• when two nucleotides bond they form a phosphodiester bond
• phosphodiester bond forms between a pentose sugar of one nucleotide and a phosphate group of another nucleotide
• adenine and guanine are purines and thymine and cytosine are pyrimidines
• purines have a double ringed structure while pyrimidines have a single ringed structure
• when adenine and thymine bond they form two bonds
• when cytosine and guanine bond they form three bonds
• the two strands in DNA are anti parallel
• DNA is made up of two strands of repeated nucleotides