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Biological Importance of Sodium and Potassium for IIT JEE

Last updated date: 15th Apr 2024
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Biological Importance of Sodium and Potassium

Every element has a crucial role. Sodium and potassium, play a central role in the body's processes. Knowing their importance isn't just for satisfying scientific curiosity; it's also helpful for acing the JEE Main exam and taking care of your health. So, future biologists, get ready as we dive into the interesting world of these two essential elements.

Sodium: The Action Conductor

Think of a busy city with information racing through its network. That's what sodium does in our bodies. This positively charged ion (Na⁺) guides the transmission of nerve impulses – the electrical signals controlling everything from muscle movement to thought. Sodium moves across cell membranes, creating gradients that trigger action potentials, the language of our nervous system. Without sodium, our muscles wouldn't move, our hearts wouldn't beat, and we wouldn't even think.

Sodium does more than just work with neurons. It keeps fluid balanced, maintaining cell plumpness and blood volume. It helps absorb glucose and amino acids, providing fuel for our cells. And for those who love flavor, sodium, in the form of table salt, enhances the taste on our tongues.

Potassium: The Steady Element

While sodium starts the action, potassium brings a calming touch. This positively charged ion (K⁺) rules inside cells, keeping their electrical stability. It acts like a bouncer, letting specific ions in and out, guarding the delicate balance that supports cellular function.

Potassium's impact extends to muscle contraction, from the small flutter of your eyelids to the strong beat of your heart. It plays a crucial role in enzyme activity, ensuring smooth metabolic processes. And for those seeking inner peace, potassium helps regulate blood pressure, keeping the body in balance.

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 other elements. Sodium-ion and potassium ions play different roles in metabolism. Na+ is an extracellular ion and K+ is 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 mold-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 the 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. Health is affected when the body has too much and too little sodium. 


Sodium distribution in species


Sodium is a micronutrient that aids in the 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 as limiting sodium uptakes by roots stored in cell vacuoles and controlling 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 living beings for the function of all 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 concentrations. 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. 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 functions 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 ions 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

The benefits of Potassium have a very vast range in human health but it is highly underestimated. Nonetheless, now it is high time to give acknowledgment 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 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 minimizing the risk of any kind of heart problem.

  1. 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 a kidney stone problem as the assemblage of materials that might form in concentrated urine. A typical mineral found in kidney stones is Calcium. Various studies claim that Calcium levels 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 to your diet to fight against the kidney stone problem. A four-year study claimed that people who take a potassium-rich diet on a per daily 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 kidney stone disease. 

  1. Keep Protected From Blood Pressure Problems-

Blood pressure is a kind of disease that directly impacts the heart and brain. Blood pressure leads to the fatal problem of heart attack and brain hemorrhage. By removing excess sodium from the body, a potassium-rich diet might be able to reduce blood- pressure. Increased levels of sodium in the body can easily lift up the blood pressure especially in the case where a person already has a high blood- pressure problem. A consolidated result of 33 studies deduces that a potassium-rich diet has favorable 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 later blood pressure got decreased by 1.96 mmHg. 

  1. 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 urination and reduce the levels of sodium. 

  1. 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. A 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 meet 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.

Points to Remember

  • Sodium ions are found in human cells such as Nerve cells, and they regulate the flow of water across the membrane. 

  • Sodium is needed to transport the sugars and amino acids in the cells.

  • Potassium ions are found in the cells. They regulate the stomata like opening and closing of stomata.

  • Potassium ions help to maintain the osmolarity of the cell.

  • Potassium is important for the functioning of the heart and muscle and skeletal concentration.

  • Sodium and Potassium maintain the electrolyte balance of the body.

  • If the consumption of sodium is high and consumption of potassium is low then there is the chance of heart disease and risk of death too.

  • The main source of sodium is salt which is added while cooking, the other sources of sodium are cheese, carrots, eggs, etc.

  • The daily requirement of sodium is 5g to 10g for adults.

  • High consumption of salt causes high blood pressure.

  • The function of the Sodium Potassium Pump is it pumps the sodium and potassium ions and against the concentration gradient. The sodium ions are pumped out and potassium enters in.

  • Sodium potassium pump is very important as it is important for the nerve impulse transmission in the human body.

  • A normal sodium level in the human body is about 135-145 mmol/L.

  • When the sodium level drops in the human body then it is called Hyponatremia. 

  • Hyponatremia leads to headaches, nausea, or coma.


Consequences of Imbalance:

Disruptions in sodium or potassium levels can have dire consequences:

  • Hypernatremia (high sodium): Can lead to dehydration, muscle weakness, and even seizures.

  • Hyponatremia (low sodium): Can cause nausea, vomiting, confusion, and even coma.

  • Hyperkalemia (high potassium): Can cause muscle weakness, irregular heartbeat, and even cardiac arrest.

  • Hypokalemia (low potassium): Can lead to muscle cramps, fatigue, and heart rhythm abnormalities.

Maintaining the Equilibrium

Maintaining optimal sodium and potassium levels is crucial for health. Here's how diet plays a key role:

  • Sodium: Limit processed foods, canned goods, and excessive salt intake. Focus on fresh fruits, vegetables, and whole grains.

  • Potassium: Embrace fruits like bananas, oranges, and melons, vegetables like potatoes and leafy greens, and dairy products like yogurt and milk.

If you have any concerns about your sodium or potassium levels, consult a healthcare professional for personalized advice.

Tips to Master this Chapter

Biology is a subject that some students find tough and some find it easy because it has more things to remember in this subject and there are practical things that are done in the lab. It is vast but it is an interesting subject. In order to ace in this chapter, students might follow the tips given below -

  • Be attentive in class - Students might think they know the chapter and might not be attentive to which they will be left behind with many doubts later or may not understand the chapter.

  • Read the chapter - Students should keep in practice to always read or study the chapters after it is taught in the class. This will help the students to get whether they have understood the topic or not.

  • Write down the doubts - After studying the topic students might have some doubts to which they should write it down so that they can ask their teacher.

  • Make notes - Students should always make notes while the teacher teaches in class. They can make the notes in short but in a way that they can understand and will be easy to revise just by reading the notes. They can always make their own notes by referring to the book and notes. This will help the student to learn and remember in the process of making the notes.

  • Practicals - Students should be attentive while the practicals are done in the lab, by watching the experiments they can get the knowledge of the topic. This has helped many students to remember the topic.

  • Study to understand - don't just read the powerpoints, notes, and books. Try to understand the topic while reading it.

  • Discuss with your friends - discussing with others about any topics makes the topic more interesting because this will be more interactive. Friends can also share knowledge which might be important.

  • Try to test yourself - After completing studying a topic students should take a test for themself which will make the student know which concepts are not clear and can be cleared with the teachers or tutors.

  • Solve the questions - After completing the chapter a student should try to solve the questions given at the back of the chapter. This will cover half of the chapter’s topic and will help the students to know the type of questions are present in the chapter. 

  • Solve previous question papers - This step will help the students who will appear for the board exams, they should collect the last year's question papers and try to solve the answers by themselves. This will give them some idea about the pattern of the question paper and the questions which are important. 

  • Practice diagram - In biology students need to keep practicing to draw the diagram because some questions might come in which makes the diagram might be important.

  • Students can always download the study materials from Vedantu regarding any topic of Biology from the website. The previous year's question papers are also available on the website of Vedantu and can be downloaded in PDF form. If they still have any doubts then they can join the online live - classes in Vedantu.


Sodium and potassium might sound basic, but they play a crucial role in our cells, which is essential for life. By knowing what they do and keeping a good balance, we can keep our body working smoothly. This helps us stay healthy and lively. So, when you enjoy something salty or eat a delicious fruit, think about the important work sodium and potassium are doing in the background to keep you going strong.

FAQs on Biological Importance of Sodium and Potassium for IIT JEE

1. How do sodium and potassium maintain electrolyte balance?

They achieve this by establishing a concentration gradient across the cell membrane. Sodium is higher outside the cell, while potassium is higher inside. This gradient drives both active and passive transport mechanisms, regulating electrical signals, osmotic pressure, and fluid distribution throughout the body.

2. What roles do sodium and potassium play in nerve impulses?

Sodium ions primarily contribute to nerve impulse transmission. Their movement into and out of nerve cells generates the action potential, the electrical signal that propagates along the nerve fiber.

3. How do sodium and potassium affect muscle contraction?

Both ions are crucial for muscle contraction. Potassium ions maintain the resting membrane potential of muscle cells, while sodium influx triggers muscle fiber contraction. This coordinated interplay facilitates muscle function.

4. What are the consequences of sodium and potassium imbalances?

High sodium intake can lead to hypertension, heart problems, and stroke. Conversely, low sodium levels can cause hyponatremia, causing weakness, muscle cramps, and confusion. Deficiencies in potassium can weaken muscles, disrupt heart rhythm, and cause respiratory paralysis.

5. How do plants utilize sodium and potassium?

Sodium plays a secondary role in plants, aiding in metabolism and chlorophyll synthesis. Potassium, however, is crucial for plant growth and function. It maintains turgor pressure (cell rigidity), regulates stomata opening and closing, and activates several enzymes involved in plant processes.

6. What are some dietary sources of sodium and potassium?

Sodium is abundant in processed foods, salt-added products, and cured meats. Natural sources include table salt and seafood. Potassium is widely available in fruits, vegetables, dairy products, and fish.

7. Why is understanding sodium and potassium important for JEE Main?

These elements are fundamental to understanding cell membrane transport, nerve and muscle function, and electrolyte balance. Questions related to their roles in biological processes may appear in the Chemistry or Biology sections of the JEE Main exam.