Nitrogen Cycle Flashcards
Describe another process carried out by microorganisms which adds ammonium ions to soil
(2)
-saprobionts broken down by aa
-to ammonium ions
Explain how ploughing would affect the fertility of the soil
(3)
-more O2 availability
-more nitrification
-more nitrates
suggest two ways in which crop rotation may lead to high crop yields
(2)
-less pests cuz prefer diff crops so cant infest
-diff crops like diff minerals=soil recovery
what is the enzyme that has nitrogen as a substrate?
(1)
-aa
Explain why nitrogenase also catalyses reactions involving other substances
(2)
-similar shapes
-more E.S complexes
suggest two advantages of a very high rate of aerobic respiration for NF bacteria in the absence of O2
(2)
-more respiration means more ATP means more energy for NF
-causes less O2 so works best in anaerobic env
Why would genetically engineered cereal plants grow more slowly?
(2)
-ATP used for NF
-less ATP for growth
explain how hollow roots allows it to take up nitrogen-containing substances
(2)
-needs ATP
-via active transport
why will the nitrate conc fall if human sewage flow is too fast?
(2)
-wash bacteria away
-less NF
Explain how a decrease in temp would affect the rate of CO2 conc
(2)
-enzymes
-less E.S complexes
what does reduced NAD do when apple slices were transferred to nitrogen?
(2)
-needs e-
-reduced NAD reduces pyruvate acid
Explain why the rate of CO2 production is higher when the apple slices were in nitrogen than in the air?
(3)
-respiring anaerobically
-less ATP
-more glucose respired to produce same amount of ATP
Freshwater marsh soils are normally waterlogged. This creates anaerobic
conditions.
Use your knowledge of the nitrogen cycle to suggest why these soils
contain relatively high concentrations of ammonium compounds and low
concentrations of nitrite ions and nitrate ions.
(2)
-less O2 so denitrification
-so less ammonium ions converted to nitrites to nitrates
