Nutrient cycles

• First Process of nitrogen cycle 


  nitrogen fixation - N2 makes up 78% of air. nitrogen fixing bacteria convert nitrogen into ammonium ions. plants can absorb and use these ions. Some plants like legumes have nodules in their roots containing these bacteria E.g clover
• 2 nitrogen cycle 


  Nitrification - ammonium can be converted into nitrite ions and then into nitrate ions by nitrfying bacteria. this is the main form that the majority of plants use for their N.
• 3rd process: Denitrification 


  denitrifying bacteria convert nitrates and Nitrides back into nitrogen so it does not accumulate into the soil as it has negative effects on the environment e.g overgrowth in water ways
• 4th process: ammonification 


  Saprophytes break down organic matter (dead living matter). they convert the nitrogen compounds into ammonium ions and therefor available for plants to use and be further converted by bacteria in soil.
• 5th Process: Assimilation 


  Microbes also help plants and animals take up N compounds from the environment and incinerate them into their biomass
• Carbon cycle: decomposition 1 


  Saprophytes break down organic matter (including dead plants and animals). C in the form of organic compounds is converted into carbon dioxide and returned into the atmosphere
• Carbon cycle 2: photosynthesis 


  Phytoplankton (microscopic plants) in the sea use carbon dioxide from the atmosphere and convert it into carbohydrates/ organic matter.
• carbon 3: respiration 


  Plants and animals respire and release carbon as carbon dioxide back into the atmosphere
• Carbon cycle 4: carbon sequestration 


  Certain microbes (e.g soil) can help stabilise and store C in the soil, reducing the amount of C in the atmosphere
• 5 carbon cycle: Methane and Production and consumption 


  Microbes are involved in this and the methane is a greenhouse gas. methane genetic archaea produce methane in an aerobic environments, while methane oxidising bacteria consume it and convert it into CO2
• What is the main way microbes add to the atmosphere carbon? 


  Respiration
• What is the main way microbes take up carbon? 


  Decomposition - Saprophytes
• Assimilation --> Nitrogen for biomass (protein)