And this leaves just the central core of the haemoglobin called the haem group, which is what's known as a porphyrin ring.    From Wordnik.com.  [- The Naked Scientists Naked Science Radio Show PODCAST - Stripping Down Science] Reference

Other nutritional virtues include the easily absorbed iron known as "haem" iron.    From Wordnik.com.  [Top stories from Times Online] Reference

"Non-haem" iron from plant foods such as baked beans, nuts, seeds and dark green, leafy vegetables is less well absorbed than "haem" iron in meat.    From Wordnik.com.  [Top stories from Times Online] Reference

New York to work with Irving, who had long been interested in the haem question.    From Wordnik.com.  [Tim Hunt - Autobiography] Reference

haem iron is most readily absorbed by the body and also increases the uptake of non-haem iron.    From Wordnik.com.  [cas·sou·let] Reference

haem iron is only found in animal tissues, non-haem iron is found in grains, fruits, vegetable, legumes, nuts and eggs.    From Wordnik.com.  [cas·sou·let] Reference

He had given Kendrew and me bench space in his biochemistry laboratory for the preparation of our crystals and was keenly interested in all haem proteins, including haemoglobin.    From Wordnik.com.  [The Medical Research Council Laboratory of Molecular Biology] Reference

Non-vegetarian haem iron from meat and fish is best absorbed.    From Wordnik.com.  [Find Me A Cure] Reference

The oxygenase domain contains the binding sites for haem, BH¬4, L-arginine and zinc.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The first cycle involves two electrons from the reductase domain, haem, O2, and BH4.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

Figure 5, showing the important active site residues of human iNOS bound with cofactors haem.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The process begins when the Fe3+ ion in the haem is reduced to Fe2+ by the electron from FMN.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The process releases haem - a potentially deadly molecule that parasites can sequester and detoxify.    From Wordnik.com.  [Naturejobs - All Jobs] Reference

The reductase domain accepts electrons from NAPH and, by shuttling them via FAD and FMN to the haem iron.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

Reniere ML, Skaar EP (2008) Staphylococcus aureus haem oxygenases are differentially regulated by iron and haem.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Four of the studies were human and employed non-haem iron levels measured by double isotope technique and whole body counting.    From Wordnik.com.  [NutraIngredients RSS] Reference

Both catalyze the oxidation of substrates that are very closely held (but not coordinated) to the Fe ion of the haem cofactor.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

Rings from a Tryptophan (194 in iNOS) and a phenylalanine (369 in iNOS) sandwich the porphyrin ring of the haem and help stabilize it.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

Functionally, the reductase domain receives electrons from NADH and donates them, one by one, to haem on the oxygenase domain of its sister monomer.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

It is to donate electrons to the haem group on the oxygenase domain, thereby reducing its Fe3+ to ferrous iron and allowing the reaction to proceed.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

Here, we unraveled a rapid molecular reprogramming of the Hb structure-function triggered by virulent haemolytic pathogens that feed on the haem-iron.    From Wordnik.com.  [Naturejobs - All Jobs] Reference

The haem cofactor is placed deeply within the protein and undergoes extensive van der Waals interactions with nearby hydrophobic and aliphatic residues.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The binding of arginine and BH4 are necessary to induce the haem group's redox potential, and make it low enough to take electrons from the reductase domain.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

For stable oxygen binding without haem oxidation, water is excluded by simple packing of the protein interior and loops that reduce helical-interface mobility.    From Wordnik.com.  [Uncommon Descent] Reference

The haem group is held in a penta-coordinate configuration and is axially coordinated to the adjacent cysteine (number 200 in human iNOS, 184 in eNOS and 419 in nNOS).    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The absorption of "non-haem" iron is also reduced by the presence of tannins in the diet in tea and phytates, types of plant chemicals found in vegetables like spinach.    From Wordnik.com.  [Top stories from Times Online] Reference

The second one again sees the haem group react with electrons from the reductase domain and O2 but this time the presence of NHA causes a different pathway to be performed.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The presence of these species would make it likely that BH4 plays a catalytically active role, perhaps with BH5+ donating an electron to the haem and becoming BH4. in the process.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

Mitochondria need iron in order to function, but they also convert iron into other chemical forms used throughout the cell: iron sulphur clusters and haem - one of the building blocks of haemoglobin.    From Wordnik.com.  [PhysOrg.com - latest science and technology news stories] Reference

As a consequence, the mitochondria don't receive enough iron, so they can't function properly, and can't make enough haem and iron sulphur clusters available to the cell machinery that depends on them.    From Wordnik.com.  [PhysOrg.com - latest science and technology news stories] Reference

The researchers created a backbone of three carbon rings that encourage binding to haem, then added a side chain that targets the drug to the membrane-bound compartment in which the parasites sequester haem.    From Wordnik.com.  [Naturejobs - All Jobs] Reference

It has also been found that the NOSes reduce the oxidative stress caused by iron or haem-protein associated mechanisms and reduce lipid peroxidation, both of which damage tissues in inflammatory pathologies.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The substrate L-arginine binds to a side chain terminus fitted tightly into the narrow part of the dimerization funnel cavity with its guanidino group positioned close to and coplanar to the iron atom on the haem.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

I vas not vant der let haem git advantage mit me. ".    From Wordnik.com.  [Donahoe's Magazine, Volume 15, No. 1, January 1886] Reference

There are two types of iron, haem and non-haem.    From Wordnik.com.  [cas·sou·let] Reference