nitrogen cycle

Cards (24)

  • Why is the nitrogen cycle important?
    Animals and plants can't obtain nitrogen gas
  • What makes nitrogen gas inert?
    It contains a triple bond
  • What do microorganisms do in the nitrogen cycle?
    They break nitrogen bonds
  • How do plants absorb nitrogen?
    Through active transport in the roots
  • Which biological molecules contain nitrogen?
    Proteins, ATP, and nucleic acids
  • What are the four key processes of the nitrogen cycle?
    1. Nitrogen fixation
    2. Ammonification
    3. Nitrification
    4. Denitrification
  • What is ammonification?
    Creation of ammonium from organic matter
  • What is nitrogen fixation?
    Converting nitrogen gas into nitrogen compounds
  • Where does nitrogen fixation occur in plants?
    In root nodules
  • Which plants have root nodules for nitrogen fixation?
    Leguminous plants
  • What do nitrogen-fixing bacteria convert nitrogen gas into?
    Ammonium or nitrates
  • What is the process of nitrification?
    Conversion of ammonium to nitrites and nitrates
  • What are the two stages of nitrification?
    Ammonium to nitrites, nitrites to nitrates
  • How do plants absorb nitrates?
    By active transport from the soil
  • What do animals produce that contains nitrogen?
    Waste containing ammonia
  • What role do decomposers play in the nitrogen cycle?
    They break down proteins into nitrogen compounds
  • What is the result of the decomposition of dead plants and animals?
    Release of nitrogen-containing compounds
  • What is denitrification?
    Conversion of nitrates back to nitrogen gas
  • Why is denitrification undesirable in agriculture?
    It leads to loss of nitrogen from soil
  • When does denitrification occur?
    When soil is waterlogged and anaerobic
  • What is the oxidation process in nitrification?
    Ammonium to nitrite to nitrate
  • What must be specified in exam questions about decomposers?
    The nitrogen-containing compound involved
  • What nitrogen-containing compound is found in animal urine?
    Urea
  • What nitrogen-containing compound is found in dead plant matter?
    Proteins