wk1 (central dogma)

• Central Dogma


  Explains the flow of information in cells from DNA-RNA-make proteins
• Purines


  • A, G
• Pyrimidines


  • C, T
• Both DNA and RNA will undergo complementary base pairing which contain both Purine and Pyrimidine
• Deoxyribonucleic acid (DNA)


  The molecule that carries genetic information for the development and functioning of an organism
• DNA


  • The structure of the DNA provides a mechanism for making accurate copies of the molecule
  • The process of making copies of DNA is called replication
  • When DNA replicates, two identical copies of DNA molecules are produced, which are exactly the same as the original
• James Watson and Francis Crick worked out that DNA is double helix like a twisted staircase


  1953
• DNA structure


  • The two sugar-phosphate backbones make up the sides and the base pairs make up the rungs or steps of the twisted staircase
• Ribonucleic acid (RNA)


  A molecule present in most living organisms and viruses, comprising nucleotides, ribose sugars attached to nitrogenous bases and phosphate groups
• RNA nitrogenous bases


  • Adenine
  • Guanine
  • Uracil
  • Cytosine
• Pyrimidines


  • C, U
• DNA Replication


  • The genetic information in DNA is duplicated to form an identical copy of the DNA molecule
  • Ensures that genetic information is passed on from one generation of cells to the next during cell division
• All DNA have a semi-conservative strand due to replication process
• DNA Replication happened inside the nucleus of the cell
• DNA Replication


  1. Helicase breaks the bond between nitrogenous bases, splitting the two strands of DNA

  2. DNA polymerase adds complementary nucleotides to each strand to form new strands

  3. Primase initiates the process by synthesizing RNA primers

  4. Ligase finalizes DNA replication, sealing any gaps and connecting Okazaki fragments on the lagging strand
• Helicase


  An enzyme that untwists/unwinds and separates the double-stranded DNA, creating the template for synthesis
• DNA polymerase


  Plays a central role, adding nucleotides to the growing strand, ensuring accurate genetic information transfer
• Primase


  Initiates the process by synthesizing RNA primers, essential for polymerase to extend the strands
• Ligase


  Finalizes DNA replication, sealing any gaps and connecting Okazaki fragments on the lagging strand, ensuring a complete and functional double helix
• Proteins


  • Composed of several amino acid polymers known as the polypeptides
  • A protein's three-dimensional structure determines its size, form, and function
• Genetic code


  The language of guidance in the mRNA, using a mixture of just three letters at a time (codon)
• Gene


  Coding part of the DNA for a specific trait
• Transcription


  1. Information from a DNA sequence is transcribed to make a copy into a complementary RNA sequence

  2. The RNA molecule called messenger RNA (mRNA) serves as a temporary copy of genetic instructions and carries them from the cell nucleus to ribosomes in the cytoplasm

  3. RNA polymerase connects complementary RNA to the DNA
• Translation


  1. RNA messages travel from the cell nucleus to the ribosome in the cytoplasm where they are read to make specific proteins

  2. tRNA (transfer RNA) decodes mRNA into amino acid, carrying amino acids to the ribosome