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Cells: light microscope
Key words
Generalized animal cell
cellulose
chloroplast
cytoplasm
nucleus
photosynthesis
plasma
membrane
vacuole
nucleus
nuclear envelope
nucleoplasm
nucleolus
plasma membrane
cytoplasm
food granules
Cell size
Typical cells are anything between
.005 and .025 mm (.0002 and .001 in).
This is about ten times smaller than
the diameter of a human hair.
● Light microscopes can only see
relatively large structures in a cell
because they can only magnify up to
1,000X.
●
Animal cells
The cell contains a large nucleus,
which helps to control the cell. The
nucleus is separated from the
cytoplasm by the nuclear envelope
(membrane). Inside the nucleus, the
nucleoplasm, the liquid matrix of the
nucleus, surrounds the nucleolus,
where proteins are synthesized.
● The area outside the nucleus but
within the outer membrane is called
the cytoplasm. It often contains a
collection of smaller bodies such as
food or secretory granules, and
sometimes small vacuoles (small sacs
enveloped in a membrane). These are
often very difficult to see with a light
microscope.
●
secretory granules
Generalized plant cell
cell wall of
neighboring cell
cell wall
plasma envelope
Plant cells
Plant cells are surrounded by a thick
cell wall made of cellulose.
● Immediately inside the cell wall is the
plasma membrane of the plant cell.
This is identical to the plasma
membrane of animal cells.
● Plant cells have a large central vacuole
that occupies much of the cell volume.
It stores salts, water, water soluble
pigments, and potentially toxic
molecules in the form of crystals.
● The cytoplasm contains many of the
inclusions (globules, granules, etc.)
found in animal cells and a large
vacuole. Sometimes large green discshaped bodies called chloroplasts are
present: these carry out
photosynthesis.
vacuole
chloroplast
cytoplasm
nucleus
nucleolus
nucleoplasm
nuclear
envelope
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