Define mechanism for copper absorption, Biology

Assignment Help:

Define Mechanism for Copper Absorption?

As in the case of other minerals, copper absorption appears to occur by two mechanisms:

i) Saturable active mechanism, which operates when the copper concentration is low, and

ii) Passive diffusion, which occurs at a higher concentration.

Efficiency of absorption varies from 30-50% of ingested copper. Copper absorption is influenced by copper status. Absorption is significantly higher during periods of low dietary copper and vice-versa. Various dietary factors influence copper absorption. Dietary components exerting positive effect include amino acids especially histidine, organic acids such as citric, gluconic, lactic, acetic and malic acids. Dietary components which inhibit absorption include high intakes of several nutrients such as zinc, iron, molybdenum, calcium, phosphorus and excessive intake of antacids. Once copper is within the intestinal cell, it may be used by the cell, may be stored in the cell or may be transported across the basolateral membrane.

Copper transport across the basolateral membrane into the plasma appears to occur by a carrier- mediated active transport, specific for copper. Copper which is not absorbed is excreted in the faeces. So, what happens to the copper which is absorbed? After absorption, ionic copper is tightly bound to plasma proteins, namely albumin and transcuprein and is transported via portal blood to the liver. Small amount of absorbed copper is also transported to other tissues especially kidney. In the lives, copper is incorporated into Ceruloplasmin, which is then released in the blood. Ceruloplasmin constitutes 95% of the total plasma copper. Ceruloplasmin then delivers copper to various tissues. Tissues can also acquire copper from albumin, transcuprein and low molecular weight copper compounds. Copper enters the cell directly through channels or after binding to protein transporters. Ascorbic acid enhances copper transfer. Glutathione appears to serve as a transporter of copper within the cell. In the cell, copper is incorporated into various copper enzymes and proteins such as cytochrome oxidase. Most absorbed copper is secreted by the liver into the bile to be excreted in the faeces. This process is the major regulator of copper elimination. Only small amount of copper (10-50 mcg) is excreted through kidney. Thus, the absorption and excretion process of copper helps in maintaining optimum levels of this element in our body so that it can help in performing a number of metabolic reactions in the body. Let us then learn about the role of copper in our body.


Related Discussions:- Define mechanism for copper absorption

What are the problems regarding terrestrial environment, Q. What are the pr...

Q. What are the problems that vertebrates needed to solve to adapt to the terrestrial environment since they came from the aquatic habitat? How evolution does solve those problems?

How much nacl can be made using 30g of nacl, How much of a 10% w/v of nacl ...

How much of a 10% w/v of nacl can be made using 30g of nacl? Please show all steps.

Determine the chain in the dna molecule, Which type of chemical bond mainta...

Which type of chemical bond maintains the pairing of each chain in the DNA molecule? To produce the DNA molecule, purine bases bind to pyrimidine bases by intermolecular bonds

Explain coronary heart disease, Apart from any inherited tendency towards c...

Apart from any inherited tendency towards coronary heart disease, what are thought to be the four major risk factors?  The four major risk factors for coronary heart disease ar

Implications of pharmacogenomic research, Problem 1: Describe the funct...

Problem 1: Describe the functions of: a. Glutathione transferases b. Sulfotransferases. -Describe the functions of: a. Glutathione transferases Describe the functions of

How is the concentration of drugs in human plasma defined, Some drugs bind ...

Some drugs bind extensively to plasma proteins (Warfarin binds 99%) while others have virtually no binding. Extraction depends on the type of drug - there are dissimilar standar

What is post myocardial infarction ventricular septal defect, What is Pos...

What is Post Myocardial Infarction Ventricular Septal Defect ? Post Myocardial Infarction Ventricular Septal Defect (Septal Rupture) The correct terminology is septal

Is total volume of the reaction is 30 micro liters, You have a 10x enzyme b...

You have a 10x enzyme buffer that you are to use in a particular reaction. The total volume of the reaction is 30 micro liters. How much of the 10x buffer should you add so that th

Urea, #questionwhy is urea the major nitrogenous excretory product..

#questionwhy is urea the major nitrogenous excretory product..

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd