OCR A Level Biology - Nucleotides and Nucleic Acids | Questions with 100% correct Answers | Verified

Nucleotide - Monomer that forms DNA and has a phosphate group, a sugar, and a nitrogencontaining base. DNA - A complex molecule containing the genetic information that makes up the chromosomes. RNA - A single-stranded nucleic acid that passes along genetic messages. Purines - Nitrogenous bases that have a double ring of carbon and nitrogen atoms, such as adenine and guanine. Pyrimidines - Nitrogenous bases that have a single ring of carbon and nitrogen atoms, such as cytosine and thymine ADP - Adenosine diphosphate; a molecule that ATP becomes when it gives up one of its three phosphate groups. ATP - Adenosine triphosphate; the main energy source that cells use for most of their work. Polynucleotide - A polymer consisting of many nucleotide monomers in a chain; nucleotides can be those of DNA or RNA. Phosphodiester bond - The bond between the phosphate of one nucleotide and two sugar molecules. DNA helicase - An enzyme that unwinds the DNA double helix during DNA replication.DNA polymerase - Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecul