Define proteins as biological buffers, Biology

Assignment Help:

Define Proteins as biological buffers?

Proteins have the ability to accept or donate hydrogen ions and by doing so they serve as biological buffers. In blood, there are three important buffering systems - plasma proteins, haemoglobin and carbonic acid bicarbonate. The equilibrium reactions for each of these buffering systems are as follows:

1549_Define Proteins as biological buffers.png

The first of these buffering systems, the plasma proteins, functions as a weak acid1 salt buffer when the free carboxyl groups on the protein dissociate, or as a weak base/salt buffer when the free amino groups dissociate. Although the buffering ability of the plasma protein is extremely important in maintaining blood pH, it is not as important as the other two systems, the second buffering system, carbonic acid-bicarbonate, is extremely effective because there are reactions which follow this equilibrium which will regulate either acids or bases.

The H2CO3 level in plasma never goes too high because it is in equilibrium with CO2 (H2CO3 → CO2 + H2O), which is expired by the lungs. In blood, this equilibrium proceeds very quickly because of the presence of carbonic anhydrase, an enzyme found in red blood cells which catalyze it. If the carbonic acid-bicarbonate reaction goes in the opposite direction, the concentration of the HCO3- so formed will be regulated by the kidneys. The third important buffering system in blood results from haemoglobin. Haemoglobin has six times the buffering power of the plasma proteins. It functions well as a buffer because it is present in large amounts, it contains 38 histidine residues (Histidine residues are good buffers because they can dissociate to H+ and the imidazole group) and because haemoglobin exists in blood in two forms, reduced haemoglobin and oxy haemoglobin. It is thus a weaker acid and a better buffer.

 


Related Discussions:- Define proteins as biological buffers

Aerobic cellular respiration during muscle exercise, Q. What happens when t...

Q. What happens when the oxygen supply is inadequate to maintain aerobic cellular respiration during muscle exercise? If oxygen from myoglobin or hemoglobin is not enough for t

#title.protozoa classes., #question.give the classes of protozoa phylum in ...

#question.give the classes of protozoa phylum in detail with examples .

What are the physical signs of mitral stenosis, Q. What are the Physical Si...

Q. What are the Physical Signs of mitral stenosis? A typical malar flush is described in mitral stenosis. It is difficult to appreciate in Indians. Pulse is normal or low volum

Define about the pyranose and furanose ring structure, Define about the Pyr...

Define about the Pyranose and Furanose ring structure? Monosaccharides forming a five-sided ring or a five membered ring (4 C and 1 O), like ribose, are called furanoses. Those

Swine fever, S w i n e fever It is also known as hog cholera and re...

S w i n e fever It is also known as hog cholera and results in high fever and prostration. E t iology : Pestivirus belonging to family Togaviridae is responsi

In which area lengthening of long bones occurs, Lengthening of long bones i...

Lengthening of long bones in humans takes place in a specific area of the bone. This area is known as the: a) Cancellous bone b) Medullary canal c) Periosteum (pron: per-

Define species of biological species concept, Define species according to t...

Define species according to the biological species concept. What two problems often make this definition impractical?

Explain contractile proteins, Explain Contractile Proteins These protei...

Explain Contractile Proteins These proteins participate in contractile processes such as muscle proteins as well as those found in other  cells and tissues. In the latter, thes

Explain marine oils, Marine oils These oils typically contain large amo...

Marine oils These oils typically contain large amounts of long - chain omega-3-polyunsaturated fatty acids, with up to six double bonds and they are usually rich in vitamins A

Assessment of diastdlic function, Q. Assessment of Diastdlic Function? ...

Q. Assessment of Diastdlic Function? Myocardial ischemia Clters diastolic function of left ventricle. The earliest abnormality to appear with prolonged ischemia is delayed my

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