• DNA


  deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
• Chromosome Eukaryotes


  - linear DNA double helix

  - Bound to proteins called histone

  - found in the nucleus

  - introns and exons present

  - DNA is further packaged through progressive levels of DNA coiling and folding.
• chromosome of a prokaryote


  - a single, double stranded circular DNA molecule.

  - Found in the nucleoid of the cytosol

  - unbound (no proteins)

  - no introns
• Nucleus


  A part of the cell containing DNA and RNA and responsible for growth and reproduction
• Nucleoid


  A non-membrane-enclosed region in a prokaryotic cell where its chromosome is located.
• Nucleotide


  A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
• nitrogenous bases in DNA

  An organic base: adenine, guanine, cytosine, thymine
• Nitrogen bases in RNA

  adenine, guanine, cytosine, uracil
• double helix


  two strands of nucleotides wound about each other; structure of DNA
• DNA replication


  The process in which DNA makes a duplicate copy of itself.
• complementary base pairing


  In DNA, T pairs with A; G pairs with C;

  RNA, U pairs with A and G pairs with C
• Chromatin


  the unravelled condensed structure of DNA (bound to histones) for the purpose of packaging into the nucleus. long thread
• Chromosomes


  the highest condensed structure of the DNA double helix for the proper separation of the genetic material. Coiled and folded
• sister chromatids


  Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.
• Histones


  protein molecules around which DNA is tightly coiled in chromatin
• Gene


  sequence (a section of DNA) that codes for a protein and thus determines a trait
• Cytosol


  Fluid portion of cytoplasm
• antiparallel strands


  Strands parallel to each other going in opposite directions (3'-5' and 5'-3')
• 5 prime to 3 prime


  The direction in which DNA and RNA are synthesized (made/replicated)
• semi-conservative


  in each new DNA double helix, one strand is from the original molecule, and one strand is new
• DNA polymerase


  Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
• DNA helicase


  An enzyme that unwinds the DNA double helix during DNA replication
• DNA ligase


  an enzyme that joins the sugar-phosphate backbones during replication
• free-floating nucleotides


  nucleotides that are present in the nucleus and are used during DNA replication