Carbon cycle

Respiration

When living organisms respire (plants, animals, microorganisms ), they release carbon dioxide back into the atmosphere ( this is a form of excretion )

Fossilization

if conditions are not favorable for the process of decomposition, dead organisms decay slowly or not at all. These organisms build up and, if compressed over millions of years, can form fossil fuels (coal, oil or gas).

How it is passed along from one organism to the next

Animals eat the plants and the carbon in the plants becomes part of the animal's fats and proteins. Microorganisms and some animals feed on animal waste and the remains of dead animals and plants. The carbon then becomes part of these organisms.

Factors that contribute carbon dioxide to the environment

Combustion of fossil fuels releases carbon dioxide into the atmosphere. Plants take away carbon dioxide from atmosphere during photosyntheses; destroying trees and other vegetation increases levels of co2 and decreases oxygen in atmosphere as no photosynthesis takes place.

Feeding

Feeding moves carbon in the form of biological molecules along the food-chain.

Photosynthesis in carbon cycle

Plants absorb carbon dioxide from the atmosphere and form it into sugar, starch and other biological compounds. This is the only process in the cycle that decreases the levels of carbon dioxide in the atmosphere.

Combustion

The burning of fossil fuels releases stored carbon back into the atmosphere.

human effects on carbon cycle

Burning fossil fuels releases carbon that has been sequestered for millions of years underground- this increases atmospheric concentrations of Co2. Destroying forests and other forms of vegetation diminishes the ability for photosynthesis to remove carbon dioxide away from the atmosphere which also results in a net increase and causes a long-term enlargement in atmospheric co2.

How it is returned...

Carbon dioxide is released into the atmosphere through respiration of plants, animals and microorganisms. It is also released by combustion of wood and fossil fuels (oil, coal, gas). Burning of fossil fuels is gradually increasing co2 levels in atmosphere.

Describe decomposition or decay during carbon cycle

Decomposition and decay also releases carbon dioxide. It happens faster in warm, moist conditions with plenty of oxygen and vice versa.

Discuss the effects of the combustion of fossil fuels and the cutting down of forests

Photosynthesis takes carbon dioxide out of the atmosphere and replaces it with oxygen. Respiration and combustion take up oxygen and replace it with carbon dioxide. When fossil fuels are burnt during combustion, the carbon in them combines with oxygen in the air and forms carbon dioxide. The burning of fossil fuels is thought to be having an effect on the balance of carbon dioxide as the extra carbon dioxide may be causing the percentage of it in the atmosphere to increase. Moreover, the loss of trees may be reduce the amount of photosynthesis taking place which means that the concentration of co2 increases and that of oxygen decreases. The rise in levels of co2 levels in the atmosphere may be dangerous as it could cause global warming.

Describe how carbon is removed

Plants absorb co2 from the atmosphere during photosynthesis. The carbon then becomes part of the plant's complex molecules such as proteins, fats and carbohydrates.

Describe the carbon cycle

The carbon cycle is the process in which carbon is passed from the atmosphere, as carbon dioxide, to living things. First carbon enters the atmosphere by respiration and combustion. Producers then absorb the carbon dioxide from the atmosphere during the process of photosynthesis to make carbohydrates. Consumers eat the plants and the carbon from the plants becomes part of the animal's fats and proteins and the carbon compounds are passed along the food-chain. Most carbon they consume is exhaled as carbon dioxide during respiration. Plants and animals eventually die. These dead organisms are eaten by decomposers and the carbon in their bodies is returned as carbon dioxide back into the atmosphere. In some conditions, decomposition is blocked and plant and animal material turn to fossil fuels- available for future combustion.

Egestion

The removal of feces from an animal that will contain carbon. This egested material may be broken down during egestion.

Decomposition

When complex carbon compounds in dead organisms, in urine and in feces, are broken down into simpler carbon compounds by bacteria or fungi.

Excretion

When waste is removed from the body (urine). This excreted material may be broken down during decomposition.