13 energy and ecosystem Flashcards
what is the simple sequence of nutrient cycles
- nutrient is taken up by producers as simple inorganic molecules
- the producer incorporates the nutrients into complex organic molecules
- when the producer is eaten the nutrients passes into the consumer
- it then passe along the food chain
- when the producers and consumers die, their complex molecules are broken down by saprobiontic microorganisms that release the nutrients in its organic simple form
what is nitrogen used for
the manufacture of proteins and nucleic acid
how do plants gain nitrogen
in the form of nitrate ions (No3-) form the soil through active transport by the roots
how do animals gain nitrogen
by eating and digesting plants
what are the 4 process involved with the nitrogen cycle
- ammonification
- nitrification
- nitrogen fixation
- denitrification
what is ammonification
- the production if ammonia form organic nitrogen containing compounds (urea, proteins, nucleic acids and vitamins)
- saprobiontic microorganisms feed on faeces and dead organisms materials releasing ammonia which forms ammonia ions in the soil
what is nitrification
- oxidation reaction carried out by nitrifiying bacteria that releases energy
1. oxidation of ammonium ions to nitrate ions(no2-)
2. oxidation if nitrate ions to nitrate ions (no3-)
what is nitrogen fixation
- nitrogen gas is conveted into nitrogen contain compounds
- can be carried out industrially or naturally through lightening passing through the atmosphere
- carried out by free living nitrogen fixing bacteria and mutralistic nitrogen fixing bacteria
what are naturalistic nitrogen fixing bacteria
- live in nodules of bean plat roots
- obtain carbohydrates from the plats and the plants acquire amino acid form the bacteria
what are organic natural fertilisers
- consist of dead and decaying remains of plant and animals and waster matter
what is artificial inorganic fertiliser
- are mined form rocks and blend together to get the appropriate blend of minerals
organic components that contain nitrogen
- amino acids
- ATP
- DNA
benefits of nitrates to a plant
- develop earlier
- grow taller
- greater leaf area
detrimental effects of nitrogen containing fertilisers
- reduces species diversity
- leaching
- eutrophication
how does nitrogen fertileser reduce species diversity
- nitrogen rich soil favours fast growing plats like grass and nettle
- other species are then outcompeted so die
- species rich meadows only survive if there are low levels of nitrogen allowing other species to grow
what is leeching
- the process nutrients are removed form the soil
leeching process
- rainwater dissolves soluble nutrients, carrying them deep into the soil where plant roots cannot reach
- the leached nitrate ions find themselves in rives and stream then drain into freshwater lakes
- may have a harmful effect on human if in drinking water
what is eutrophication
the process where nutrient concentration increase in bodies of water
process of eutrophication
- naturally low concentration of nitrates in lakes and rivers, making it a limiting factor for plant and algae growth
- leeching lead to an increase in nitrate concentration so it no longer becomes a limiting factor for plant growth
- algae grows on the surface of the water (algae bloom)
- dense layer of algae absorbs light and prevents it form reaching the lower depts
- light becomes a limiting factor for the plants lower down so they die
- saprobiontic bacteria grow using the dead organisms
- the bacteria requires oxygen for respiration so oxygen concentration decreases
- aerobic organism die as they have not oxygen
- anaerobic organisms population rises as they no longer have competition
- anaerobic organism release more nitrate and toxic waste making the water putrid
what is the source of energy for all ecosystems
the sun
what is gross primary productivity (GPP)
- the total quantity of plant biomass stored in a given area at a given time
what is net primary productivity (NPP)
the chemical energy store that is left after the looses of respiration has been taken into account
why is there a low percentage of energy transferred at each stage in the tropic levels
- not all of the organism is consumed
- some parts are consumed but cannot be digested so lost as faeces
- some energy is lost in excretory material like urine
- some energy is lost as heat form respiration
what are producers
photosynthetic organism that manufacture organic substances using light energy, water, carbon dioxide and mineral ions
