DNA and ATP

• The pyrimidines are cytosine (binds to g) , thymine (binds to a) and uracil (binds to a in RNA)
• The purines are adenine (binds to t) and guanine (binds to c)
• The chargaff rule states that for every % of one nucleotide type, its complimentary pair will be in the same proportion except on a single strand
• DNA is a polymer of nitrogenous bases joined to a hexose sugar - deoxyribose - by glycosidic bonds, these deoxyribose sugars are bound to two phosphate groups by phosphodiester bonds.
• MRNA is a single strand of RNA nucleotides which is copied from the DNA template before having the introns spliced from it as it leaves the nucleus
• Every triplet encoded on a strand of MRNA codes for one amino acid carried by a TRNA molecule
• Transfer RNA or TRNA is a clover shaped molecule with an anticodon and an amino acid binding site, held together by hydrogen bonds
• DNA is replicated by semi conservative replication where the original molecule is split into two template strands which become apart of the new molecule
• DNA helicase will break the hydrogen bonds between nucleotides, exposing the bases to free floating nucleotides in the nucleus.
• Free floating nucleotides activated by ATP will be attracted to complimentary nucleotides on the template strand
• Once complimentary bases are lined up in DNA replication, DNA polymerase will join the nucleotide bases in condensation reactions to form phosphodiester bonds, hydrogen bonds will form between the bases
• DNA has a phosphodiester backbone to prevent any damage to the only copy of the cells genetic information- it will never leave the nucleus
• Meselson and Stahl used heavy nitrogen to see how DNA was replicated, by adding heavy nitrogenous bases to DNA made with normal nitrogenous bases, they tracked each replication using centrifuge density bands - after 1 replication 50% are heavy, after 2, 75%v are heavy proving semi conservative theory
• Adenosine triphosphate is made from the nitrogenous base adenine, ribose sugar and three phosphate groups
• ATP is made from glucose as it is a faster, more controlled burst of energy
• When ATP is hydrolysed it becomes ADP + Pi
• ATP is adapted as it is soluble, releases a small amount at a time and is a one step reaction