Proteins play a fundamental role in
nearly all [?] processes. Due to
their diversity they can assume many
different configurations and they can
play varied roles in and .

Some protein functions are noteworthy:
the [?] function (cell membrane
proteins, [?] proteins, proteins
of the connective tissue), the [?]
function (enzymes are proteins), the
energy storage function (proteins can
be [?] into acetyl-CoA and “cycle”
the Krebs cycle), the [?] regulation
function (albumin), the transportation
function (membrane channels,
respiratory pigments), the
protection function (antibodies), the
function (contractile
proteins), the endocrine integration
function () and the
informative function (membrane
receptors, intracellular [?]). There
are also many proteins whose biological
functions are not yet known.