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

Dealcoholism, DEALCOHOLISM - Treatment of alcoholism or withdrawal s...

DEALCOHOLISM - Treatment of alcoholism or withdrawal symptoms of alcohol is known as dealcoholism. Recovery from alcohol dependence is greatly aided by sociobehavioural c

Importance of dark period, Importance of Dark Period For quite sometim...

Importance of Dark Period For quite sometime the role of light period (photoperiod) was emphasised in flowering? However, based on certain experiments it was realised that it

Reciprocal regulation of glycolysis and gluconeogenesis, Glycolysis generat...

Glycolysis generates two ATPs net per glucose whereas gluconeogenesis uses four ATPs and two GTPs per glucose. Thus, if both glycolysis and gluconeogenesis  were  allows  to  opera

How are gametes formed in the pteridophyte life cycle, Q. How are gametes f...

Q. How are gametes formed in the pteridophyte life cycle, by mitosis or meiosis? What is the type of meiosis that occurs in pteridophytes? In pteridophytes gametes are made by

Why alkaline phosphatases use water as a second substrate, Alkaline Phospha...

Alkaline Phosphatases use water as a second substrate. Why do we still treat their kinetics as if they were for a single-substrate reaction?

What are some of the things scientists may do analyze data, What are some o...

What are some of the things scientists may do to analyze data? They may use statistics to determine relation- ships among variables, compare the data with those obtained in ot

Stable atoms have no vacancies in their outer shell, Select all that are tr...

Select all that are true/correct: Stable atoms have no vacancies in their outer shell. Hydrogen is more stable than carbon Helium is more stable than carbon Helium is more stable t

Open or blunderbuss apex or divergent roots, Open or Blunderbuss Apex or di...

Open or Blunderbuss Apex or divergent roots The mechanical cleaning & shaping of teeth with blunderbuss canal apex are very difficult if not impossibly orthogratly due to 1

Biological functions in which chlorine ions participate, Q. What are the ma...

Q. What are the major biological functions in which chlorine ions participate? Like sodium cations, chlorine anions actively participate in the regulation of the osmolarity of

How are nematodes characterized, Q. Nematode identity card. How are nematod...

Q. Nematode identity card. How are nematodes characterized according to examples of representing beings, type of symmetry basic morphology, , germ layers and coelom, digestive syst

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