C 4.2 Transfers of energy and matter

Syllabus statements

C4.2.1 Ecosystems as open systems in which both energy and matter can enter and exit

C4.2.2 Sunlight as the principal source of energy that sustains most ecosystems

C4.2.3 Flow of chemical energy through food chains

C4.2.4 Construction of food chains and food webs to represent feeding relationships in a community

C4.2.5 Supply of energy to decomposers as carbon compounds in organic matter coming from dead organisms

C4.2.6 Autotrophs as organisms that use external energy sources to synthesize carbon compounds from simple inorganic substances

C4.2.7 Use of light as the external energy source in photoautotrophs and oxidation reactions as the energy source in chemoautotrophs

C4.2.8 Heterotrophs as organisms that use carbon compounds obtained from other organisms to synthesize the carbon compounds that they require

C4.2.9 Release of energy in both autotrophs and heterotrophs by oxidation of carbon compounds in cell respiration

C4.2.10 Classification of organisms into trophic levels

C4.2.11 Construction of energy pyramids

C4.2.12 Reductions in energy availability at each successive stage in food chains due to large energy losses between trophic levels

C4.2.13 Heat loss to the environment in both autotrophs and heterotrophs due to conversion of chemical energy to heat in cell respiration

C4.2.14 Restrictions on the number of trophic levels in ecosystems due to energy losses

C4.2.15 Primary production as accumulation of carbon compounds in biomass by autotrophs

C4.2.16 Secondary production as accumulation of carbon compounds in biomass by heterotrophs

C4.2.17 Constructing carbon cycle diagrams

C4.2.18 Ecosystems as carbon sinks and carbon sources

C4.2.19 Release of carbon dioxide into the atmosphere during combustion of biomass, peat, coal, oil and natural gas

C4.2.20 Analysis of the Keeling Curve in terms of photosynthesis, respiration and combustion

C4.2.21 Dependence of aerobic respiration on atmospheric oxygen produced by photosynthesis, and of photosynthesis on atmospheric carbon dioxide produced by respiration

C4.2.22 Recycling of all chemical elements required by living organisms in ecosystems