p2: nutrient cycles Flashcards
nitrification process
- via nitrifying bacteria
- ammonia to nitrates via nitrites
denitrification process
- by denitrifying bacteria
- nitrates to oxygen gas
- nitrates to nitrites
nitrogen fixation
- nitrogen fixing bacteria
- nitrogen gas to ammonia
decomposition process
- saprobionts
- ammonification
- nitrogen containing compounds to ammonia
where is nitrogen found?
- amino acids
- proteins
- nucleic acids: DNA/RNA
- ADP
- ATP
-NADP - NAD/FAD
EXPLAIN what is meant by the term carbon sink
- takes up CO2
eg: coal, peat, trees
explain what is meant by global warming
- increase of mean global temperature
- CO2 is a greenhouse gas
- reflects back long infrared waves in the atmosphere
- increased greenhouse effect
- leads to melting ice caps, flooding, climate change
describe the role of saprobionts in the nitrogen cycle
- decompose proteins/DNA/RNA
- releasing ammonia
describe how the action of microorganisms in the soil produces a source of nitrates for crop plants
- DNA converted into ammonia
- by saprobionts
- ammonia into nitrates
- by nitrifying bacteria
- nitrogen gas to ammonia
- by nitrogen fixing bacteria
explain how caron containing compounds present in pine leaves that fall from the trees are absorbed and used for growth by saprobionts/fungi that live in the soil
- extracellular digestion
- by secretion of enzymes
- absorption of soluble products
- synthesis of natural compunds
- respiration provides energy for growth
nitrogen compounds in the plants are amde available after poughing in spring.
describe the role of microorganisms in this process.
- proteins/AA broken down
- deamination to release ammonium compounds
- by saprobionts
- conversion of nitates via nitrites
- by nitrfying bacteria
- nitrates absorped into roots by active transport
the scientist used units of micrograms/ grams for the concentration of ammonia in soil. suggest why, in this investigation, the scienitsists use this unit.
- very ltitle ammonia in soil
- avoids use of lots of decimal places
- to allow comparisons
give 2 examples of biological molecules containing nitrogen that would be removed when a crop is harvested
- amino acids
- dna
-rna
0NAD
-chlorophyll
-ATP
plants absorb a number of other nutrients from the soil including phosphates. describe why phosphates are needed by a growing plant.
- production of phospholipids
- synthesis of ATP
- production of ATP
- production of RNA
- production of NADP
describe how a lack of phosphates in the soil surrounding a plant can affect its growth
- required to make ATP so less energy for growth
- required to make nucleotides so less DNA
- required to make RuBP so less CO2 fixed
- required to make phospholipids for membranes