Topic 4.3 Carbon cycling

Anaerobic organisms

occur in the absence of oxygen or do not require oxygen to live. For example, anaerobic bacteria produce energy from food molecules without the presence of oxygen.

Autotrophs organisms

that use solar energy or chemical energy to manufacture the organic compounds they need as nutrients from simple inorganic compounds obtained from their environment.

Biomass

the total mass of living matter within a given unit of environmental area.

Carbohydrates

any of a large group of organic compounds, including sugars and polysaccharides, such as cellulose, glycogen, and starch, that contain carbon, hydrogen, and oxygen, with the general formula (CH2O)n. They are an important source of food and energy for animals.

Carbon dioxide (CO2)

a colourless, odourless, incombustible gas present in the atmosphere and formed during respiration, the decomposition and combustion of organic compounds, and in the reaction of acids with carbonates.

Carbon flux

the flow of carbon from one carbon pool to another.

Cell respiration

a series of metabolic processes that take place within a cell in which biochemical energy is produced from organic substances and stored in ATP for use in the energy-requiring activities of the cell.

Fossilised organic matter

when remains of organisms of a past geologic age have been preserved in a fossil form.

Gigatone

equivalent to a one billion tonnes.

Limestone

a sedimentary rock consisting mainly of calcium carbonate, deposited as the calcareous remains of marine animals or chemically precipitated from the sea.

Methane (CH4)

an odourless, colourless, flammable gas. It is the major constituent of natural gas, which is used as a fuel, and is an important source of hydrogen and a wide variety of organic compounds.

Peat

a compact, brownish deposit of partially decomposed vegetable matter saturated with water, it found in uplands and bogs in temperate and cold regions and used as a fuel.

Waterlogged soil

a soil that is soaked or saturated with water.