Biomass/Bioenergy - Environmental Impacts of Renewable Energy - page 171

hydrophobic, polar uncharged, or ionizable. The interactions among the
side chains, the amide protons, and the carbonyl oxygen help create the
three-dimensional shape of the protein.
PLANT BASICS *
Biotechnology can not only transform materials extracted from plants but also trans-
form the plants to produce more valuable materials. Selective breeding and genetic
engineering can be used to improve production of chemical, as well as food, fiber,
and structural products. Plants can be developed to produce high-value chemicals
in greater quantity than they do naturally, or even to produce compounds they do
not naturally produce (NREL, 2002). To optimize plant biomass for more efficient
processing requires a better understanding of plants and plant cell-wall structure
and function. The plant kingdom ranks second in importance only to the animal
kingdom (at least from the human point of view). The importance of plants and
plant communities to humans, bioenergy production, and their environment cannot
be overstated. Some of the important things plants provide are listed below:
Aesthetics —Plants add to the beauty of the places where we live.
Medicine —80% of all medicinal drugs originate in wild plants.
Food —90% of the world's food comes from only 20 plant species.
Industrial products —Plants are very important for the goods they provide
(e.g., plant fibers provide clothing), and wood is used to build homes.
Recreation —Plants are the basis for many important recreational activities,
including fishing, nature observation, hiking, and hunting.
Air quality —The oxygen in the air we breathe comes from the photosynthesis
of plants.
Water quality —Plants aid in maintaining healthy watersheds, streams, and
lakes by holding soil in place, controlling stream flows, and filtering sedi-
ments from water.
Erosion control —Plant cover helps to prevent wind or water erosion of the top
layer of soil that we depend on.
Climate —Regional climates are impacted by the amount and type of plant cover.
Fish and wildlife habitat —Plants provide the necessary habitat for wildlife
and fish populations.
Ecosystem —Every plant species serves an important role or purpose in its
com mu n it y.
Feedstock for bioenergy production —Some important fuel chemicals come
from plants, such as ethanol from corn and soy diesel from soybeans.
Although both are important kingdoms of living things, plants and animals differ
in many important aspects. Some of these differences are summarized in Table 5.2 .
Before discussing the basic specifics of plants, it is important to first define a few key
plant terms.
* Adapted from Spellman, F.R., Biology for the Non-Biologist , Government Institutes Press, Lanham,
MD, 2009.