Section outline

    • Why is an understanding of biomass necessary?

      All Earth's bioenergy originates from the sun. Only a small proportion of the Sun's energy incident on the Earth's surface is fixed by organic matter and stored.

      This energy is recycled through a series of natural and chemical conversions. At some stage in the cycle we can intervene and use the bio-energy when it is optimally suited to act as a source of chemical energy and hence as a fuel

      It is essential to understand the basics of cell biology, cell chemistry and cell metabolism in order to gain a deeper insight into the energy that is stored in biofuels. It is for this reason that the fundamentals of biochemistry are covered in the first parts of this unit. The last section covers the process of photosynthesis. This is the process whereby plants convert solar energy to chemical energy, which is stored as a carbohydrate, cellulose.

      Study tips

      This unit consists of a series of compact study notes and self-test questions. You are recommended to study the unit in the following sequence:

        1. Tackle the pre-test questions, where available, to gauge your prior knowledge. This will indicate whether you need to concentrate on a particular unit.
        2. From the "Syllabus" page, work through the study notes sequentially. Make sure that you understand any worked examples.
        3. Where available, you may wish to tackle the self-test questions as they occur in the sequence. If you encounter difficulties, return to the study notes and focus on the relevant topics before re-visiting the self-test.

      Objectives

      After completing this topic, you should understand:

        • After completing this topic, you should understand the basic structure of a cell and the differences between prokaryotic and eukaryotic cells.
        • Describe the processes of metabolism at the cellular level
        • Outline the bioenergetics of cellular metabolism
        • Describe the biochemical pathways relevant to catabolism
        • Explain in detail the biochemical processes involved in photosynthesis