Biological Importance of Sodium and Potassium for IIT JEE

Benefits of Potassium

It has been found that an average human body weighing 70kg contains 0.07kg sodium, 0.25kg of potassium and the rest another elements. Sodium ion and potassium ion play different roles in metabolism. Na+ being an extracellular ion and K+ being an intracellular ion. The K+ may be substituted in living tissues by large single- charged ions while the relatively small Na+ ions can be substituted by Li+ions. The mammalian tissues incorporate a sodium and potassium ion transport system which is known as sodium or potassium pump. The sodium pump ensures the desired ratio of sodium ion and potassium ion concentration in the extracellular and intracellular spaces. The K+ ion concentrations in most animal cells range from 0.12 to 0.16 mould-3 while Na+ ion in the same cell does not exceed 0.01 mol dm-3. The ratio in the extracellular fluid is reserved. Thus, there is a considerable gradient of concentrations of Na+ and K+ ions between the two cellular ions. For maintaining the distribution, energy is needed for k+ ions to accumulate inside the cells and Na+ ions to be taken out. It has been confirmed that the pump forcing Na + ions out and driving K+ ions into cells, functions aided by phosphate protein which forms more stable compounds with K+, as compared to Na+. The phosphate protein interacts with adenosine phosphate inside the cell.

Sodium in Biology

Sodium ion (Na+) is necessary for some types of plants in a small amount, but sodium as a nutrient is more generally needed for animals in larger amounts because it is used for generation of nerves impulses and for maintenance of electrolyte balance and fluid balance. Sodium ions are necessary for the aforementioned functions in animals. It is also necessary for heart activities and certain metabolic functions. The health is affected when the body has too much and too little sodium.

Sodium distribution in species

Sodium is a micronutrient that aids in metabolism, and synthesis of chlorophyll in plants. It substitutes for potassium in several roles like aiding in the opening and closing of stomata and maintaining turgor pressure. Concentrations in the cytoplasm can lead to enzyme inhibition, which in turn causes necrosis and chlorosis like excess sodium in the soil limits the uptake of water due to decreased water potential, which may result in wilting. Plant develop these mechanisms for avoiding such problems like limit sodium uptakes by roots stored them in cell vacuoles and control them over long distances, limiting the damage to new growth.


Some plants need sodium in a small amount so a completely plant-based diet will generally result in low sodium in the body. This requires some herbs to obtain sodium from mineral sources and salt licks. The best response is sodium for the pure salty taste.


The minimum requirement for sodium is between 115 and 500 milligrams per day. It is dependent on the sweating due to physical activities and whether the person is adapted to the climate. The major source of sodium in the diet is Sodium Chloride. The acceptable quantity consumption for sodium is 1.2 to 1.5 grams per day.

Potassium in Biology:

Potassium is an essential mineral micronutrient. It is the main intracellular ion for all types of cells while having a major role in the maintenance of fluid and electrolyte balance. Potassium is necessary for all the living beings for the function of all the living cells. It is present in all plant and animal tissues. It is found in plants cell and in the mixed diet with especially high concentration. It is found most highly concentrated in fruits. Plants usually possess a high concentration of potassium. This is turn is related to the relatively very low level of sodium found in plants. Hence in the beginning, people used to isolate potassium from the ashes of plants. The heavy crop production rapidly depletes soils of potassium due to the high concentration of potassium in plants, and the agricultural fertilizers consume 93% of the potassium chemical production of the modern world economy. 

The function of sodium and potassium in living organisms are quite different. Animals employ sodium and potassium differently to generate an electrical potential in animal cells.

Function in Plant:

Potassium provides an ionic environment for metabolic processes in the cytosol. A deficiency of potassium ion can impair a plant’s ability to maintain these processes. It also functions in other processes such as protein synthesis, photosynthesis and maintenance of cation: anion balance in the cytosol and vacuole.

Function in Animals:

Potassium is the major cation inside animal cells. Membrane potential can be described as the difference between the concentrations of these charged particles which results in a difference in the electric potential both from the inside and the outside of the cells. Ion transporter is to maintain the balance between potassium and sodium in the cell membrane. The cells have the ability to produce an electrical discharge which is very critical for body function. 

Benefits of Potassium in health issues:

Benefits of Potassium have a very vast range in human health but it is highly underestimated. Nonetheless, now it is a high time to give the acknowledgement to the benefits of Potassium in human health. We are stating the benefits under some categories:

1. Keep protected from strokes-

Strokes are very common these days. Every year around 1, 25,000 people are losing their precious life because of these strokes. Strokes occur in the body if there is a lack of blood flow to the brain. To skip this illness, people must eat a potassium-rich diet on a daily basis. The study shows that people who eat a potassium-rich diet per day have a 24% lower risk of getting a stroke than the person who takes the least amount of potassium-rich diet. These diets are directly linked to minimize the risk of any kind of heart problems.

2. Keep protected from kidney stones-

According to the general scenario facing kidney stone problem is a frequently occurring disease across the entire world. In general terms, we can define kidney stone problem as the assemblage of materials that might form in concentrated urine. A typical mineral found in kidney stone is Calcium. Various studies claim that Calcium level in urine can be lowered by Potassium citrate. Varieties of fruits and vegetables have a sufficient amount of potassium in them. Now you can add those veggies and fruits in your diet to fight against the kidney stone problem. A four-year study claimed that people who take a potassium-rich diet on per day basis have 51% fewer chances to get this kidney stone disease. On the other hand, a twelve-year study claims that people who take a potassium-rich diet on a per day basis have 35% fewer chances to get affected by the kidney stone disease. 

3. Keep protected from blood pressure problem-

Blood pressure is a kind of disease which directly impacts the heart and brain. Blood pressure leads to the fatal problem of heart attack and brain haemorrhage. By removing excess sodium from the body, a potassium-rich diet might be able to reduce the blood- pressure. Increased level of sodium in the body can easily lift-up the blood-pressure especially in the case where a person already has the high blood- pressure problem. A consolidated result of 33 studies deduces that a potassium-rich diet has favourable effects on systolic and diastolic blood pressure. In an experiment, some people took an increased level of potassium intake. As a result, their prior blood pressure got decreased by 3.49 mmHg and their latter blood pressure got decreased by 1.96 mmHg. 

4. Keep reducing water retention-

When excess fluids start building up in a body, the person faces the problem of water retention. Factually, the water retention problem has been treated by potassium. The function of potassium is to increase the urination and reduce the levels of sodium. 

5. Keep protected from osteoporosis-

In osteoporosis there are porous and hollow bones. One of the most important minerals for the best bone health, calcium has minimal existence in this disease. Potassium-rich diet gives a boost to the calcium level which gets reduced by urination. In a cluster of 62 most healthy women who have the age between “45-55” show the greatest total bone mass only because of a potassium-rich diet. On the other hand, the study of 994 pre-menopausal healthy women stated that these women were taking a potassium-rich diet and had more bone mass in their hip bones and lower back.

Drawbacks of having a less and high quantity of Potassium-

Data of one anonymous country shows that there are only less than 2% of people meeting the prescribed recommendation of potassium. However, there would be no harm in having less potassium quantity in the body as it doesn’t cause such deficiency. In spite of that, when the human body suddenly starts losing a heavy quantity of potassium this situation starts causing major deficiencies in the body. When the human body is not able to remove minerals through urination then excess blood potassium occurs. 

Finally, we can say that potassium must be an integral part of our daily diet.