Gen Bio 2 - Molecular Biology

• Explains the flow of genetic information. The flow of information: DNA -> RNA -> Protein


  Central Dogma
• A molecule found inside every cell that contains the instructions an organism needs to develop, live, and reproduce

  Deoxyribonucleic acid or DNA
• Carries information of aminoacid sequence from the genes to where proteins are assembled on ribosomes in the cytoplasm

  Ribonucleic Acid or RNA
• Three major types of RNA:

  • Messenger RNA (mRNA)
  • Transfer RNA (tRNA)
  • Ribosomal RNA (rRNA)
• Each combination of three nitrogenous bases on theRNA is a codon, a three-letter code for a specific aminoacid.
• Ribonucleic Acid or RNA carries the genetic informationcopied from DNA in the form of a series of three-basecode “words,” each of which specifies a particularamino acid.
• The process by which the instructions are converted into the functional product is called gene expression.

  • The central dogma states that the pattern of information that occurs most frequently in our cells is: (a) From existing DNA to make new DNA (DNA replication); (b) From DNA to make new RNA (transcription); (c) From RNA to make new proteins (translation).
• The process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules

  Replication
• Main Enzymes in Replication:

  • Helicase
  • RNA Primase
  • DNA Polymerase
  • Ligase
• The “unzipping enzyme”. They separate double-stranded DNA into single strands


  Helicase
• The “initializer”. Helps DNA polymerase where to start by using its RNA primer. Primase makes the primer


  RNA Primase
• The “master builder enzyme”. It is an enzyme that builds new strands of DNA and it has proofreading ability.

  • Polymerase Activity: attaching of nucleotides.
  • Exonuclease Activity: Proofreading and repair


  DNA Polymerase
• The “the gluer”. Helps glue the DNA fragment together

  Ligase
• A process in which a particular segment of DNA is copied into mRNA by the enzyme RNA polymerase. It occurs inside the nucleus


  Transcription
• The process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus


  Translation
• Ala

  Alanine
• Arg

  Arginine
• Asp

  Asparticacid
• Cys

  Cysteine
• Glu

  Glutamic acid
• Asn

  Asparagine
• Gln

  Glutamine
• Gly

  Glycine
• His

  Histidine
• Ile

  Isoleucine
• Leu

  Leucine
• Lys

  Lysine
• Met

  Methionine
• Phe

  Phenylalanine
• Pro

  Proline
• Ser

  Serine
• Thr

  Threonine
• Trp

  Tryptophan
• Tyr

  Tyrosine
• Val

  Valine