How should I start my essay about photosynthesis and respiration?

Question

I have to write a two page report on why CO2 emissions is important in our world today and photosynthesis & respiration's impact in our lives. I know all the information. But how should I start the introduction paragraph?

Answer 1

Try this:

The ultimate source of energy for all life on earth is the sun.  Photosynthesis is the "doorway" for the entry of this energy.

Answer 2

Photosynthesis is the conversion of light energy into chemical energy by living organisms. The raw materials are carbon dioxide and water; the energy source is sunlight; and the end-products are oxygen and (energy rich) carbohydrates, for example sucrose, glucose and starch. This process is arguably the most important biochemical pathway,[1] since nearly all life on Earth either directly or indirectly depends on it. It is a complex process occurring in higher plants, phytoplankton, algae, as well as bacteria such as cyanobacteria. Photosynthetic organisms are also referred to as photoautotrophs.[1]

The word comes from the Greek photo-, "light," and synthesis, "putting together

Cellular respiration, the process in which the chemical bonds of energy-rich molecules such as glucose are converted into energy usable for life processes

Anaerobic respiration, a process that allows respiration without use of oxygen

Plant respiration, the enzymatic oxidation of substrates in plants, leading to the release of carbon dioxide respiration is g*y.