5.22 Understand how reforestation and use of sustainable resources show effective management of conflict between human needs and conservation

Give the definition of a biofuel

A fuel produced from renewable sources/recently living plant biomass

Explain why biofuels are considered carbon neutral.

-the growing of the plants to produce them takes in carbon dioxide via photosynthesis

-this makes up for the carbon dioxide released by burning the biofuels

First generation biofuels are made from sugars and vegetable oils found in food crops. Explain why using first generation biofuels instead of petrol and diesel could reduce global warming (4)

-burning fossil fuels releases carbon dioxide

-carbon dioxide is a greenhouse gas

-carbon dioxide is taken in for the light-independent stage of photosynthesis during production of plants for biofuels

-no net change of carbon dioxide in the atmosphere when biofuels are burnt

Explain why cellulose has to be treated with enzymes before the bacteria can use it as as energy source

-bacteria can't break down cellulose fast enough

-enzymes needed to break down cellulose into beta glucose

-by hydrolysing 1,4 glycosidic bonds

-bacteria can carry out respiration or fermentation of glucose

Explain how reforestation of tropical rainforests can be used to minimise climate change (3)

-new young, growing trees are planted

-resulting in net uptake of carbon dioxide, as more is taken in by photosynthesis than released by respiration

-this reduces carbon dioxide in the atmosphere

-which slows the rate of global warming