The
mannan
backbone
is
composed
of
(a
1,6)
linked
mannopyranosyl
residues
and
the
mannopyranosyl,
mannobiosyl,
and
mannotriosyl
residues
are
attached
by
(a1,2)
linkage
to
the
backbone.
The
cell
wall
occupies
about
40
per
cent
of
the
cell
volume
and
has
a
uniform
thickness
around
the
protoplast.
Cell
walls
of
yeast
can
be
removed
without
destroying
the
protoplast
by
the
use
of
specific
enzymes
that
hydrolyse
the
cell
wall.
Cell
walls
of
mycelial
fungi
contain
mostly
chitin
which
is
a
polymer
of
n-acetylglucosamine
and
may
constitute
25-30
per
cent
of
the
dry
weight
of
the
cell.
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