2

CHAPTER

23

The Chemical

Elements of

Microorganisms

No doubt you’re asking yourself what chemistry has to do with microbiology
since they seem to be two different branches of science. The simple answer is
that microorganisms are made up of chemicals, as is every organism—and all
matter. Remember that matter is anything that occupies space and has mass.
You might say that an organism is a chemical processing plant where things
are broken down into chemical elements; these chemical elements are then re-
arranged to form new things. You do this every time you ingest food. Food is a
group of chemical compounds. The digestive process rearranges these digested
chemical compounds into new substances that provide you with energy and
nutrients that are necessary for you to live. Some microorganisms called auto-
trophic organismsmanufacture their own food. Microorganisms that derive energy
from other microorganisms (food) are called heterotopic organisms.

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