4.9 Carbon Cycle

Photosynthesis : Carbon dioxide and water are combined to form glucose. The carbon dioxide comes from the atmosphere. Photosynthesis is responsible for reducing CO2.

Feeding: Producers are eaten by primary consumers and therefore the primary consumer takes in the carbon that was in the producer and uses this to grow. The primary consumer is then eaten by the secondary consumer and keeps passing through the different trophic levels. All our putting CO2 into the atmosphere through respiration.

Respiration: Releases energy and produces carbon dioxide, thus adding more CO2 to the atmosphere.

Decomposition: Eventually organisms will die and the organic molecules remaining will be broken down by decomposers such as bacteria and fungi. This will result in the release of CO2.

Combustion: The burning of fossil fuels releases CO2. Used for industry and motor vehicles to release energy for their movement. Natural-- forest fires, lightening striking plants and grassland fires.

4.11 Gas Pollution

Sulphur Dioxide is a gas that is a product of the combustion of fossil fuels such as coal and oils.

Sulphur dioxide combines with water and forms sulphuric acid found in condensed water in clouds and when it rains we call this rain acid rain.

Effects on Plants:

Trees and plants are often "burned" (top of tree is usually dead)

Causes calcium and magnesium ions to be leached out of the soil (plant can't grow)

Makes lakes acidic and releases Aluminium ions which causes thickening of mucus in a fish and reduces the ability to take in oxygen

Carbon Monoxide

Produced when fossil fuels such as gas are burned with insufficient oxygen.

The carbon monoxide joins with haemoglobin and forms carbaminohaemoglobin which blocks the haemoglobin from carrying oxygen

4.7 Energy efficieny

Energy efficiency uses a pyramid of energy. Much of the energy from the producer is lost throughout the food chain due to respiration, excretion and heat loss. All of the energy that we started with will come out when the organism dies and its body decomposes. This process of decomposing is done by decomposers.

4.6 Energy substances in food chains

The producer in the food chain converts sunlight into chemical energy. The chemical energy then takes the form of organic molecules such as Carbohydrates, Proteins and Lipids. Consisting of bonds such as :

C-H

C-O

C-C

O-H

C-N

C H O N substances all contain energy. The energy is passed on along the food chain and adjusts to each animal.

4.5c Pyramids

There are 3 different types of food pyramids:

-Pyramids of number

-Pyramids of biomass

-Pyramids of energy transfer

Pyramids of number:

These pyramids illustrate the number of organisms per trophic level, however there are problems with using this method. The pyramids sometimes goes against the laws of thermodynamics and fails to show the energy transfer between trophic levels. They can be effective but are highly limited.

Pyramids of biomass:

Bio=living and mass=g/kg

Biomass is based on dry mass and tends to be measured in kg/area. It is difficult to find out the dry biomass of each organism per trophic level.

Pyramids of energy transfer:

This measures the movement of energy from on trophic level to another. It follows the laws of thermodynamics and cannot be inverted. It is measured in Joules or KJ/m squared/time (seconds/minutes/years). This method is also extremely hard to calculate.

4.5b Food Webs

The food webs of the ecosystem describe the feeding interaction within a community. It shows organisms feeding at different trophic levels. Organisms can have multiple trophic levels, they can also have multiple prey, multiple predators and everything becomes linked. In many cases, animals can both be primary and secondary consumers.

4.5a Food Chains

The food chain connects the Produce-> Primary Consumer-> Secondary Consumer-> Tertiary Consumer

There is 1 organism per trophic level

The food chain shows the flow of matter and energy