2.3 dna

• nucleotide: a chemical unit consisting of a phosphate molecule, a deoxyribose sugar, and nitrogen-containing base molecules: adenine, cytosine, thymine or guanine. two complementary nucleotide chains combine to form DNA
• base pair: the two nucleotides connected on opposite sides of complementary strands of the DNA molecule. complementary base pairings for DNA are adenine with thymine and cytosine with guanine
• histone: a protein that acts like a spook for DNA to wind around, it helps to compact and package the DNA in the nucleus
• replication: the process of making two DNA molecules from one original molecule prior to cell division
• amino acid: one of the 20 possible building blocks of proteins determined by the genetic code of DNA
• DNA triplet code: three adjacent nitrogen bases found on a gene that codes for the amino acid to be produced, begin, or end the reading to a gene