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Cell
| Definition: |
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The basic subunit of
any living organism;
the simplest unit that
can exist as an independent
living system. There
are many different types
of cells in complex organisms such as humans,
each with specific characteristics. |
| Source:
GreenFacts, based on American Lung Association
Glossary |
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| More: |
| Cells are surrounded
by a cell membrane (and
cell wall in bacteria
and plants = a membrane
plus some chemically more
stable structures, often
mixtures of proteins and
polysaccharides) and contain
all necessary elements
to sustain life; proteins,
nucleic acids, lipids,
minerals, and a diverse
class of metabolites.
Cells of higher organisms
(known as eukaryotes)
are subdivided into subcellular
compartments called organelles
such as the mitochondrion,
the cell nucleus, the
endoplasmatic reticulum,
the Golgi apparatus and
many smaller organelles
with highly specialized
functions. While all these
organelles are found in
animal cells, plant cells
in addition contain a
central vacuole that controls
pressure to stabilize
the cell and chloroplasts,
the site of photosynthesis
or light dependent biosynthesis
of sugars (carbohydrates). |
| Source:
What is Life glossary |
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