Physiological importance of Acid & Bases and role of pH in human system

The physiological importance of Acid and Bases in the human body system

Acid and base participate in various physiological processes to maintain physiological balance within the human body. Acid-base balance and physiological balance in the human body are essential for several biochemical reactions inside the human body. The following are some physiological importance of acid-base in the human body system.

• 1. pH Balance: Normal body fluid pH is 7.4. That is slightly alkaline. This pH is regulated by the acid-base balance mechanism inside the human body. This pH is important for the proper functioning of the various biochemicals, enzymes, proteins, carbohydrates, metabolic reactions, etc inside the human body.

• 2. Digestion: Foods are digested inside GIT. Digestion of food depends upon the pH of the GIT. Such as protein digestion is fast inside the acidic medium in the stomach, and carbohydrate digestion is fast inside an alkaline medium of the intestine.

• 3. Enzyme activity: Enzymes act as catalysts for biochemical reactions inside the human body. The optimum activity of the enzyme is pH-sensitive. Suitable pH ensures the high activity of the enzyme.

• 4. Cellular functions: Cell membrane activity such as the transport of ions and molecules is regulated by the pH inside the cell membrane and outside the cell membrane. Cell functions depend upon pH.

• 5. Blood buffering: Blood pH is 7.4. Blood acts as a buffer. The buffering system of blood depends upon bicarbonate (base) and carbonic acid present in the blood. Disturbance in blood buffering is a life-threatening situation.

• 6. Respiratory regulation: Breathing regulates the concentration of carbon dioxide in the blood. Carbon dioxide concentration in the blood affects blood pH. The body adjusts the respiratory rate by using the acid-base balance system of the human body.

• 7. Kidney function: The kidney excretes waste materials from the blood. This excretion rate is regulated by the acid-base balance system of the human body.

• 8. Electrolyte balance: Electrolytes play an important role in several cellular functions such as impulse conduction in nerves, heart contraction relaxation, etc. The electrolytes are maintained inside the human body by the acid-base balance of the body.

• 9. Nervous system function: Proper pH balance is required around nerves for proper functioning. Any deviation in pH affects the functioning of nerve cells.

• 10 Immune System Functions: Immune cells functions at either acidic or basic environment.

Role of pH in the Human Body System

The pH stands for the potential of hydrogen. It measures the acidity and alkalinity of a solution. It is based on a scale that ranges from 0 to 14. A pH of 7 is considered neutral, while values below 7 are acidic, and values above 7 are alkaline (basic). Here are some key aspects of pH regulation in the human body:

1. Blood pH regulation: The pH of human blood lies within a narrow range of 7.35 to 7.45. Blood pH is slightly alkaline. This pH is crucial for many physiological processes, including enzyme activity, oxygen transport, and maintaining the overall health of cells. The body uses a combination of chemical buffering systems, the respiratory system (via the elimination of carbon dioxide), and the kidneys (by excreting or retaining bicarbonate ions) to maintain blood pH within this range.

2. Digestive system: Different parts of the digestive system require work at a specific pH. The oral cavity works in pH around 6.5 to 7.5. The stomach works properly in a highly acidic environment (around pH 1-2). The small intestine works properly in neutral to slightly alkaline pH (around 7-8).

3. Urinary system: The kidneys play a crucial role in regulating the body's pH by excreting excess acids or bases in the urine. This helps maintain the overall acid-base balance in the body.

4. Cellular processes: The pH of the intracellular and extracellular fluids surrounding cells must be maintained within specific ranges. Enzymes, which are essential for most cellular processes, are sensitive to pH. They work properly at an optimal pH.

5. Respiratory system: The acidic pH of blood increases the rate of respiration. An increased rate of respiration increases the excretion of carbon dioxide. Blood pH above 7.45 decreases the rate of respiration. Rapid and shallow breathing leads to the accumulation of CO2 and causes a drop in blood pH (acidosis).  Deep and slow breathing helps raise blood pH (alkalosis).

6. Immune system: Immune cells are more effective in either acidic or alkaline environments. Changes in local pH impact the immune response to infections and injuries.

7. Tissue and organ-specific functions: pH regulation is essential for the proper functioning of various tissues and organs in the body, such as the skin, eyes, and reproductive organs. Each organ has its own optimal pH environment.

Overall, the regulation of pH in the human body is a controlled and complex process. This is essential for maintaining health and allowing the body's biochemical and physiological processes to function properly. Any significant deviations from the optimal pH range lead to various health issues and disrupt essential functions.

Dr Pramila Singh

Oxidation and Reduction Reactions

Oxidation: "Loss of electron by an atom, molecule or ion is called an oxidation reaction".

• Chemicals undergo chemical changes during a chemical reaction. This involves the transfer of electrons from one atom, molecule, or ion to another atom, molecule, or ion.

• Normally addition of oxygen to a chemical or the removal of hydrogen from a chemical takes place in the oxidation reaction. A chemical that loses electrons is called an oxidizing agent. An example of oxidation is iron rusting. Iron reacts with oxygen in the presence of moisture to form iron oxide (rust).

• Oxidation reaction takes place in chemical processes, biological processes, and environmental processes.

Reduction: The gain of electrons by an atom, molecule, or ion is called a reduction reaction.

• A chemical that gains electrons is called a reducing agent.

• Normally addition of hydrogen to a chemical or the removal of oxygen from a chemical takes place in the reduction reaction. An example of a reduction reaction is the conversion of rusted iron (iron oxide) to pure iron.

• Reduction reaction takes place in various chemical processes, biological processes, and environmental processes.

Oxidation Reduction reactions: The oxidation-reduction reaction is also called the Redox reaction. The transfer of electrons between two chemicals is called a redox reaction. In a redox reaction, both oxidation and reduction processes take place simultaneously. In redox reaction following reactions take place

• 1. Oxidation: One chemical loses electron. It is associated with the addition of oxygen or loss of hydrogen

• 2. Reduction: Another chemical gain electron. It is associated with the gain of hydrogen or loss of oxygen.

Redox reaction occurs in several chemical processes and biological processes. An example of a biochemical reaction that requires a redox reaction is cellular metabolism.

A common example of a redox reaction is the reaction between hydrogen and oxygen to form water.

Hydrogen + oxygen = Water

In this reaction, hydrogen loses electrons which is an oxidation reaction. Oxygen gains electrons which is a reduction reaction.

Dr Pramila Singh