Topic 5 - definitions Flashcards
define: nitrification
The conversion of ammonia into nitrate.
define: nitrogen fixation
The conversion of nitrogen into ammonia.
define: denitrification
the conversion of nitrates into nitrogen, decreasing nitrate supply
define: mutualism
An advantageous, nutritional relationship between two species, where both species benefit.
define: saprobionts
An organism that uses enzymes externally to decompose proteins, releasing ammonia.
define: leaching
A process that removes nutrients from the soil. Soluble nutrients dissolve in rainwater and are carried deeper into the soil where plant roots cannot reach.
define: oxidation
loss of hydrogen, electrons or gain of oxygen
define: photolysis
A chemical reaction which produces protons, electrons and oxygen.
It is part of the light-dependent reaction in plants.
define: photoionisation
Light excites electrons in the plant’s chlorophyll. Electrons are lost and the chlorophyll becomes positively charged.
define: acetylcoenzyme A
A molecule resulting from the combination of acetate and coenzyme A in the link reaction
define: calorimeter
an instrument that can be used to determine the chemical energy store in a known mass of biomass.
define: GPP
The chemical energy store in plant biomass, in a given area or volume.
define: NPP
The chemical energy store in plant biomass, after respiratory losses to the environment have been accounted for.
define: ecosystem
All the living organisms and non-living components in a habitat, and their interactions.
define: conservation
Active management of an ecosystem, habitat or resource to maintain biodiversity and natural resources.
