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• Nucleotides


  Ubiquitous molecules with considerable structural diversity
• Common varieties of nucleotides

  • Composed of nitrogenous base linked to sugar to which at least one phosphate group is also attached

  
• Bases of nucleotides


  Planar, aromatic, heterocyclic molecules that are structural derivatives of either purine or pyrimidine

  
• Purines


  • Adenine (A)
  • Guanine (G)
• Pyrimidines


  • Cytosine (C)
  • Uracil (U)
  • Thymine (T)

  
• Nucleotides in polymeric forms

  DNA or RNA whose primary function is information storage and transfer

  
• Free nucleotides


  Perform enormous variety of metabolic functions not related to genetic information
• Adenosine Triphosphate (ATP)


  A nucleotide containing Adenine, Ribose and Triphosphate Group

  
• Adenosine Diphosphate (ADP)


  Formed from the process of photosynthesis or the breakdown of metabolic fuels such as carbohydrates and fatty acids
• Nucleic Acids


  Large molecules found in the nuclei of the cells that store information and direct activities for cellular growth and reproduction
• Deoxyribonucleic Acid (DNA)


  The genetic material in the nucleus of a cell, contains all the information needed for the development of a complete living system

  
• Genome


  All the Genetic Information in the cell
• Genes


  Sections of DNA that contain information to make a particular protein

  
• Ribonucleic Acid (RNA)


  Another type of Nucleic Acid that interprets the genetic information in DNA and carries that information to the ribosomes, where the synthesis of protein takes place

  
• Components of Nucleic Acids

  • Deoxyribonucleic acid (DNA)
  • Ribonucleic acid (RNA)

  
• DNA and RNA Molecules

  Each nucleotide has three components: a base, a five-carbon sugar, and a phosphate group

  
• The bases in DNA have a specific relationship: the amount of Adenine (A) is equal to the amount of Thymine (T), and the amount of Guanine (G) is equal to the amount of Cytosine (C)

  
• The number of Purine Molecules is equal to the number of Pyrimidine Molecules
• DNA Double Helix


  Two polynucleotide strands winding about each other like a spiral staircase, with the sugar-phosphate backbones on the outside and the bases arranged like steps along the inside
• Complementary Base Pairs


  Adenine forms hydrogen bonds only to thymine, and guanine bonds only to cytosine
• DNA Replication


  1. Copies of DNA are produced that transfer genetic information to the new cells

  2. The complementary base pairs form, and DNA polymerase catalyzes the formation of phosphodiester bonds between the nucleotides

  3. The entire double helix of the parent DNA is copied

  4. One strand of the new DNA molecule is from the original DNA and one is newly synthesized
• Ribonucleic Acid (RNA)


  Makes up most of the nucleic acid found in the cell and is involved in transmitting information needed to operate the cell

  
• Differences between DNA and RNA

  • The sugar in RNA is ribose rather than deoxyribose
  • The base uracil replaces thymine
  • RNA molecules are single stranded, not double stranded
  • RNA molecules are much smaller than DNA molecules

  
• Ribosomes


  Sites for Protein Synthesis, consisting of a large subunit and a small subunit
• Types of RNA


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


  Carries information for protein synthesis from the DNA in the nucleus to the ribosome
• Ribosomal RNA (rRNA)


  Most abundant type of RNA, combined with proteins in the ribosome
• Transfer RNA (tRNA)


  The smallest of the RNA molecules, interprets the genetic information in the mRNA and brings specific amino acids to the ribosome for protein synthesis
• Anticodon


  A series of three bases on tRNA that complements three bases on mRNA
• Protein Synthesis


  1. Transcription: Synthesis of mRNA

  2. Translation: mRNA to Proteins
• Genetic Code


  Consist of a series of three nucleotides (triplet) in mRNA called Codon that specify the amino acids and their sequence in the protein

  
• Genetic Mutation


  A change in the nucleotide sequence of DNA that may alter the sequence of amino acids affecting the structure and function of a protein
• Types of Mutation


  • Point Mutation: Replacement of one base in the template strand of DNA
  • Frameshift Mutation: A base is inserted into or deleted from the normal order of bases in the template strand of DNA
• Genetic Disease


  A genetic disease is the result of a defective enzyme caused by a mutation in its genetic code
• Vitamins


  Tasteless, organic compounds that are essential for maintenance of normal metabolism and must be included in the diet
• Vitamins are essential for providing good health and are necessary for many life functions
• Vitamins are nutrients that are made by living things, are required only in small amounts, and that assist many chemical reactions in the body
• Vitamins


  Comes from the Latin word "vita" meaning "Life"
• The story of vitamins dates back to this period

  18th century
• Sailors of this period knew that eating of liver cures a disease called night blindness, eating of lemons cures another disease called scurvy, and cod liver oil cures a disease called rickets