3. Nucleic Acid

    Cards (21)

    • Nucleic acids
      Made up of C, H, O, N and P
    • Nucleic acids
      Polymer made up of nucleotides (monomer)
    • Types of nucleotides
      • Deoxyribonucleic acid (DNA) nucleotides
      • Ribonucleic acid (RNA) nucleotides
    • Nucleic acids
      • Store genetic information
      • Help produce the proteins required for survival
    • Nucleotide
      Has three main components: Nitrogenous base, Phosphate group, Pentose (5 carbon) sugar
    • DNA nucleotides
      Phosphate, deoxyribose sugar, nitrogenous bases (A, T, C, G)
    • RNA nucleotides
      Phosphate, ribose sugar, nitrogenous bases (A, U, C, G)
    • Types of nitrogenous bases
      • Purines: adenine and guanine
      • Pyrimidines: cytosine, uracil (RNA) and thymine (DNA)
    • Complementary base pairing
      • Gives a constant three ring width
      • Cytosine pairs with guanine by three hydrogen bonds
      • Adenine fits with thymine or uracil, but with two hydrogen bonds
    • Nucleotides formation
      Formed by condensation reactions
    • Phosphodiester bonds

      Bonds that join nucleotides to form nucleic acids
    • DNA
      • Polymer of DNA nucleotides organized into a double helix
      • Two separate DNA polymers make up each side of the ladder
      • Sugar and phosphate molecules form the backbone, nitrogenous bases form the rungs
      • Rungs attach by hydrogen bonding
      • Complementary base pairing ensures A pairs with T, and G pairs with C
    • Coding/complementary strand
      One of the two DNA strands
    • Template strand
      One of the two DNA strands
    • DNA functions
      • To reproduce itself (replication)
      • To manufacture all of the proteins in the living organisms
    • Gene
      Section of DNA that codes for a particular protein
    • DNA in cells
      • Visible as chromosomes
      • Double helix coils up and unwinds to allow for cell cycle processes
      • Protects the molecule and allows for control of transcription
    • DNA in eukaryotic cells
      • DNA polynucleotide wraps around histones to form a nucleosome
      • Nucleosomes coil up more forming a chromatin fibre
      • Supercoiling leads to the highly condensed chromosome being visible under a microscope
      • Understanding how this coiling regulates gene expression is epigenetics
    • RNA
      • Single stranded polymer of RNA nucleotides
      • Sugar (ribose) and phosphate molecules form the vertical supports, nitrogenous bases (A, U, C, G) form the rungs
    • Types of RNA and their functions
      • mRNA
      • rRNA
      • tRNA
    • DNA vs RNA
      • RNA has a ribose five-carbon sugar, which has one more oxygen than a deoxyribose molecule
      • The nitrogenous base thymine in DNA is replaced by uracil in RNA
      • RNA is single stranded whereas DNA is double stranded