dna

• DNA

  Often called the blueprint of life, it contains the instructions for making proteins within the cell
• DNA contains the instructions needed for organisms to grow, develop, survive and reproduce
• DNA

  Controls protein synthesis
• Proteins do most of the work in cells and are the basic unit of structure and function in organisms
• Two kinds of bases in DNA

  • Pyrimidines
  • Purines
• Pyrimidines

  Single-ring bases
• Purines


  Double-ring bases
• Pyrimidines in DNA


  • Thymine
  • Cytosine
• Purines in DNA


  • Adenine
  • Guanine
• Nucleotides


  The building blocks of DNA, each composed of one phosphate, one sugar molecule, and one of the four bases
• In DNA, A always pairs with T and G always pairs with C
• RNA


  Ribonucleic Acid, a nucleic acid similar to DNA but with some structural differences
• Major types of RNA

  • Messenger RNA (mRNA)
  • Ribosomal RNA (rRNA)
  • Transfer RNA (tRNA)
• Messenger RNA (mRNA)


  Transcribes the DNA nucleotide bases to RNA nucleotides
• Ribosomal RNA (rRNA)


  Binds the mRNA and tRNA to ensure codons are translated correctly
• Transfer RNA (tRNA)


  Translates the mRNA codons into the correct amino acid
• Central dogma of molecular biology

  Describes the flow of genetic information in cells from DNA to messenger RNA to protein
• Protein synthesis


  DNA to messenger RNA to protein
• Proteins


  The executors of cell life activities, made up of amino acids
• Enzymes


  Molecules that speed up the rate of chemical reactions
• DNA replication


  1. Helicases separate the double helix

  2. Primase provides primers as starting points

  3. DNA Polymerase replicates DNA to build a new strand
• A human has 46 chromosomes or 23 pairs
• Human chromosomes


  • The first 22 are autosomes
  • The 23rd pair are the sex chromosomes (XX for female, XY for male)
• meaning of dna: deoxyribonucleic acid