Search results
Results From The WOW.Com Content Network
The human body's rate of iron absorption appears to respond to a variety of interdependent factors, including total iron stores, the extent to which the bone marrow is producing new red blood cells, the concentration of hemoglobin in the blood, and the oxygen content of the blood.
Hephaestin, a ferroxidase that can oxidize Fe 2+ to Fe 3+ and is found mainly in the small intestine, helps ferroportin transfer iron across the basolateral end of the intestine cells. In contrast, ferroportin is post-translationally repressed by hepcidin, a 25-amino acid peptide hormone. The body regulates iron levels by regulating each of ...
Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...
Within cells, iron is stored in a protein complex as ferritin or the related complex hemosiderin. Apoferritin binds to free ferrous iron and stores it in the ferric state. As ferritin accumulates within cells of the reticuloendothelial system, protein aggregates are formed as hemosiderin. Iron in ferritin or hemosiderin can be extracted for ...
Iron-binding proteins are carrier proteins and metalloproteins that are important in iron metabolism [1] and the immune response. [2] [3] Iron is required for life.Iron-dependent enzymes catalyze a variety of biochemical reactions and can be divided into three broad classes depending on the structure of their active site: non-heme mono-iron, non-heme diiron , or heme centers. [4]
A relatively non-toxic metal to humans and the second most abundant, the body has 2-3 grams of zinc. [1] It can enter the body through inhalation, skin absorption, and ingestion, [5] with the latter of the bunch being the most common. The mucosal cells of the digestive tract contain metallothionein proteins that store the zinc ions. [1]
The abundance of metal binding proteins may be inherent to the amino acids that proteins use, as even artificial proteins without evolutionary history will readily bind metals. [8] Most metals in the human body are bound to proteins. For instance, the relatively high concentration of iron in the human body is mostly due to the iron in hemoglobin.
The human body has protective mechanisms in place to prevent excess free ferric iron from circulating the body. When being transported throughout the body, iron is bound to an iron transporting protein called transferrin to prevent iron from being absorbed into different cells. [6] Any excess iron is stored as ferritin in the liver. [6]