Nucleic Acids, ATP, and Water

DNA and RNA are polymers of Nucleotides
1. DNA
  1. The pentose sugar in DNA nucleotide is deoxyribose
    1. Each have the same sugar and phosphate group
      1. Bases can differ
        A , T, C, G
  2. Used to store genetic information
2. RNA
  1. Similar structure to DNA
  2. Used to transfer genetic information from the DNA to the ribosomes
  3. RNA contains Ribose sugar
    1. also contains phosphate group
      1. and bases, A, C, U, G
3. Type of biological molecule
  1. Containing pentose sugar, organic base, phosphate group
4. Nucleotides joined together to form polynucleotides
  1. joined via condensation reactions
    1. Forming a phosphodiester bond between phosphate group and a sugar of another nucleotide
      1. Chain of sugar, phosphate called sugar-phosphate backbone
DNA is made of two polynucleotides in a double-helix structure
1. DNA polynucleotides joined by hydrogen bonding between bases
  1. Bases only join to one to another - complementary base pairing
    1. A -- T
      1. Equal base pairs in a molecule
    2. C --- G
    3. The two polynucleotides run antiparallel and twist to form helix
2. RNA is a relatively short polynucleotide chain
  1. Made from single chain
DNA Replication
1. Replicates by Semi-Conserative replication
  1. Half of the strands, in each new DNA molecule, are from the original DNA
    1. Maintains genetic continuity between cell generations
  2. Enzyme DNA helicase breaks hydrogen bonds between complementary base pairs
    1. Makes the DNA helix unwind to form two single strands
      1. These two new strands act as a template for a new strand.
        Complementary base pairing means that free DNA nucleotides are attracted to the exposed bases
        Condensation reactions join the new strands together
        Catalysed by DNA Polymerase
        Moves in opposite ways along antiparallel DNA strand
        Each end of DNA molecule is different
        3' and 5' run antiparallel - run side by side but in opposite directions
        Active site of DNA polymerase complementary to original 3' end
        New nucleotides only start on the 3' end of the orignal strand
        Meaning if antiparallel forms the 5' end of new strand at the 3' end of the orginal strand
        New strand made in the 5' to 3' direction
        DNA polymerase starts at the 3' end and moves 3' to 5' direction on the original strand
        Two DNA polymerases working on one orginal DNA double-helix move in opposite directions to each other
        Hydrogen bonds reform between the original and new bases
        Each new DNA molecule contains a original strand and a new strand
Unique Properties of Water
1. Functions or water to living organisms
  1. Metabolic processes
    1. E.g. condensation / hydrolysis reactions
    2. Water is a metabolite
  2. Used as a solvent
    1. Substances can dissolve in it
      1. Most reactions take place in solution - cytoplasm
  3. Temperature Control
    1. Takes a lot of energy to evaporate water - breaking hydrogen bonds between water
      1. Used to cool down organisms without losing too much water
    2. High specific heat capacity
      1. Resists rapid temperature changes
  4. Cohesive
    1. Stick together - helpful in water transportation in plants
      1. Cohesion - attaction between molecules of the same type
2. Structure of Water
  1. Polar molecule, partially negative oxygen and 2 partially positive hydrogens
    1. Charged ions in water will be completely surronded by water (dissolved)
      1. Positive ions will attract negative oxygen
      2. Negative ions attract positive hydrogen
      3. Water requires special channel proteins to move through membranes
        Aquaporins allow polar water to diffuse
ATP
1. Cells get energy from glucose in respiration
  1. Energy can't be used directly from glucose
    1. Use energy to form ATP
      1. ATP used to release energy
2. Made from the nuleotide base adenine
  1. ribose sugar and 3 phosphate
    1. Energy stored in bonds between the phosphate groups
      1. Hydrolysis reaction
        phosphate bond broken
        A lot of energy released
        ATP can be resynthesised using products in condensation reaction
3. Immediate source of energy
  1. ATP can diffuse to parts of the cell that need energy

Anexos de mídia

Nucleotide (binary/octet-stream)

Próximo

Nucleic Acids, ATP, and Water

Descrição

Resumo de Recurso

Anexos de mídia

Semelhante

	Criado por Dominic Weston mais de 6 anos atrás