<?xml version="1.0" encoding='utf-8'?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id="card1" title="Heavy metals - Page 19 - Wikipedia">
<p>
<a accesskey="1" href="page.php?w=Heavy_metals&amp;p=18">1.Previous</a><br />
<a accesskey="3" href="page.php?w=Heavy_metals&amp;p=20">3.Next</a>
</p>
<p><a href="page.php?w=beryllium">beryllium</a>, <a href="page.php?w=titanium">titanium</a>, <a href="page.php?w=lithium">lithium</a>, and other reactive metals) and emerging light metals (composites, laminates, etc.)"</p>

<p><big>Biological role</big></p>
<p>Trace amounts of some heavy metals, mostly in period 4, are required for certain biological processes. These are <a href="page.php?w=iron">iron</a> and <a href="page.php?w=copper">copper</a> (<a href="page.php?w=blood">oxygen</a> and <a href="page.php?w=electron_transport_chain">electron transport</a>);</p><p>
<a accesskey="1" href="page.php?w=Heavy_metals&amp;p=18">1.Previous</a><br />
<a accesskey="3" href="page.php?w=Heavy_metals&amp;p=20">3.Next</a>
</p>

<do type="prev" label="Search">
        <go href="search.wml"/>
</do>

</card>
</wml>
