Rabu, 31 Oktober 2012

PROTEIN AS THE CARRIER


Protein as Palat trasnportasi / carrier.

 Transporter protein has the ability to bind to specific molecules and transporting various substances through the blood stream. For instance:

hemoglobin, consisting of group-containing compound heme iron bound to the protein globin, serves as an oxygen carrier in the blood of vertebrates;
myoglobin, the oxygen transporter in muscle tissue;
Serum albumin, as a transporter of fatty acids in the blood;
ceruloplasmin, a copper ion transporters in darah.

-EXPLANATION

--Hemoglobin
(short: Hb) is protein molecule in red blood cells that combine with oxygen and carbon dioxide to be transported through the circulatory system to the tissue-tissue in the body. iron ions in the form of Fe 2 in hemoglobin gives red color to the blood. Normally 100 ml of blood contains 15 grams of hemoglobin capable of carrying human hemoglobin 0:03 oksigen.

Molecul gram terbina than four subunit protein globule form (namely near-Sfera). Therefore one subunit can carry one molecule of oxygen, it is effective every molecule of hemoglobin can carry four oxygen molecules. Each subunit also composed than one polypeptide chain that binds strongly the other molecules, called heme heme.
sturucture is more or less the same as chlorophyll. It consists instead of a ring-shaped protein molecule is not called porphyrin, and one atom of iron (Fe), located in the middle of last porphyrin molecule. This is where oxygen will be bound during the blood through the lungs
.
--Cerum albumin
 is a protein called albuminSering with the highest number in the body. Albumin is essential for maintaining the osmotic pressure on the distribution of body fluids between intravascular compartment and tubuh.Albumin network also serves as a carrier plasma by indirectly binding hydrophobic steroid hormones and protein bearers for hemin and fatty acids in sirkulasinya.

BSA, fraction V of serum albumin is useful to shed some substance from the blood circulation through the liver, such as bilirubin, thyroxine, taurolithocholic acid, chenodeoxycholic acid, and heme digitoksin peptides of cytochrome C. [5] 60% of the proteins in blood plasma, serum amount that exceeds normal limits can be harmful to humans. Prealbumin (English: transthyretin) is suspected as the bearers of hormone thyroxine from the blood to the brain.

--Seruloplasmin
copper compete for absorption in the digestive tract, causing one of the advantages of these minerals in the diet lead to mineral deficiencies feeds the other. RDA copper for a healthy adult is 0.9 mg daily. Copper is transported most of the bloodstream by plasma protein called ceruloplasmin. When copper was first absorbed in the stomach, he was transported to hatidan bound albumin.

cooper have an important role in a number of plant and animal enzymes, including cytochrome c oxidase copper-centered and enzymes superoxide dismutase (contains copper and zinc). Particularly those involved in catalysis and electron transfer in dioxygen transport and catalysis reaction.
 Blue copper protein involved in the transport of electrons and plastosianin termasuklah azurin. 

Blue copper name derived than blue terhasil strong absorption lines due to the transport of ligand to metal charge around 600 nm. In the oxygenation reaction of tyrosinase, ascorbate oxidase, and for the transport of oxygen (hemocyanin). Most of the biologically active copper centers found in proteins outside the cell or vesicle.

--Myoglobin
 is a monomeric protein tertiary function is to keep a back up oxygen in skeletal muscle cells (striated muscle). Protein is made up of approximately 154 amino acid sequence and contains a single heme group (porphyrin chains containing one iron atom). Gena which encodes the protein myoglobin consists of three ekson.Protein myoglobin is composed of eight alpha chain named after the latin alphabet (A through H)
unlike hemoglobin which has four heme groups, myoglobin has only one functioning piece heme group binds intracellular oxygen. Cluster heme is bound by a histidine side chain, ie the chain near the histidine (proximal) that bind heme directly in the chain of hydrophobic proteins and histidine far (distal), which serves to stabilize the heme is bound oxygen
.
Cluster histidine far also provide protection from the molecules of carbon monoxide (CO) which can enter into myoglobin.Oksigen will be used for the formation of ATP, which takes place in the mitochondrial matrix. Without the help of oxygen, the process of formation of ATP in the mitochondria will be uninterrupted.





4 komentar:

  1. on ceruloplasmin, when copper absorbed by the stomach and he was transported to the liver bound to albumin, if at that time the problem has occurred with the liver , whether the transfer of copper in the blood will not happen? or is there a switcher function of other organs that help to this process can occur.

    BalasHapus
  2. I think when there is a problem in the liver, the transfer of copper in the blood persists. but when the liver can not process the new problems may occur in the blood

    BalasHapus
  3. Copper that is not bound to protein is a toxic substance.
    amount of copper can be absorbed and damage the kidneys, inhibiting the formation of urine and cause anemia due to rupture of red blood cells (hemolysis).
    Liver can not secrete copper into the bloodstream or into the bile. As a result, the copper content in the blood is low, but copper accumulate in the brain, eyes and liver, causing cirrhosis.
    So the blood would not carry copper to the whole body jaringna karen copper accumulate in the liver

    BalasHapus
  4. i think the copper transfer does not occur. you can see by Wilson desease.the desease characterize by the accumulation of coppper in liver.

    BalasHapus

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