Energy Transfers Flashcards
Acetyl coenzyme A
A two-carbon molecule formed in the link reaction when acetate reacts with coenzyme A. It is oxidised in the Krebs cycle.
ATP (adenosine triphosphate)
Universal energy carrier found in all living cells.
aerobic respiration
A form of cellular respiration that takes place in the presence of oxygen and produces carbon dioxide, water and ATP. It involves four main stages: glycolysis, link reaction, Krebs cycle, and oxidative phosphorylation
ammonification
The production of ammonia when saprobiontic microorganisms feed on
organic nitrogen-containing compounds. Ammonium ions are formed and added to the soil.
anaerobic respiration
A form of cellular respiration that takes place in the absence of oxygen. In animals, lactate is produced. In plants and microorganisms, ethanol and carbon dioxide are produced. Less ATP is formed than in aerobic respiration.
artificial fertilisers
Man-made compounds generally containing nitrogen, phosphorus and potassium that are used to increase the mineral content of soils.
ATP synthase
An enzyme found embedded in cellular membranes that phosphorylates ADP to form ATP as protons flow through it.
biomass
The total mass of organic material, measured in a specific area over a set time period. This can be calculated in terms of dry mass or mass of carbon per given area.
calorimetry
A technique used to estimate the chemical energy store in dry biomass.
carnivores
Animals that prey on and eat other animals. They can be secondary or tertiary
consumers.
chemiosmotic theory
The synthesis of ATP through the movement of protons down their concentration gradient across a semipermeable membrane, catalysed by ATP synthase.
chlorophyll
A photosynthetic pigment located in the thylakoids of chloroplasts that absorbs light energy and becomes ionised.
coenzymes
Molecules that help enzymes carry out their function e.g. NAD, FAD, NADP.
consumers
Organisms that feed on other organisms to obtain energy.
denitrification
the conversion of nitrate ions to nitrogen gas by denitrifying bacteria
denitrifying bacteria
Anaerobic microorganisms found in waterlogged soils responsible for the reduction of nitrate ions to nitrogen gas.
ecosystem
The community of organisms (biotic) and non-living (abiotic) components of an area and their interactions.
efficiency of energy transfer
The efficiency of energy transfer between trophic levels (energy available after transfer / energy available before transfer)
electron acceptor
Oxygen acts as the final electron acceptor in the electron transfer chain
electron transfer chain
a series of electron carrier proteins that transfer electrons in a chain of oxidation-reduction reactions
eutrophication
when a body of water becomes excessively rich with nutrients (often from fertilisers)
FAD
a carrier molecule that becomes reduced when it takes up protons and electrons during the Krebs cycle, forming reduced FAD
food chain
describes the feeding relationship between organisms and the resultant stages of biomass transfer
food web
the interconnection of many different food chains in a habitat