Illustrate the significance of cell in terms of function and discuss cell structure with neat sketch.Specify the significance of biopotential electrodes. Enlist at least four biopotential electrode used in medical field and differentiate between polarizable and non-polarizable electrode?

 Illustrate the significance of cell in terms of function and discuss cell structure with neat sketch.Specify the significance of biopotential electrodes. Enlist at least four biopotential electrode used in medical field and differentiate between polarizable and non-polarizable electrode?


A cell is defined as the smallest, basic unit of life that is responsible for all of life’s processes.

Functions of Cell

A cell performs these major functions essential for the growth and development of an organism. Important functions of cell are as follows:

Provides Support and Structure

All the organisms are made up of cells. They form the structural basis of all the organisms. The cell wall and the cell membrane are the main components that function to provide support and structure to the organism. For eg., the skin is made up of a large number of cells. Xylem present in the vascular plants is made of cells that provide structural support to the plants.

Facilitate Growth Mitosis

In the process of mitosis, the parent cell divides into the daughter cells. Thus, the cells multiply and facilitate the growth in an organism.

Allows Transport of Substances

Various nutrients are imported by the cells to carry out various chemical processes going on inside the cells. The waste produced by the chemical processes is eliminated from the cells by active and passive transport. Small molecules such as oxygen, carbon dioxide, and ethanol diffuse across the cell membrane along the concentration gradient. This is known as passive transport. The larger molecules diffuse across the cell membrane through active transport where the cells require a lot of energy to transport the substances.

Energy Production

Cells require energy to carry out various chemical processes. This energy is produced by the cells through a process called photosynthesis in plants and respiration in animals.

Aids in Reproduction

A cell aids in reproduction through the processes called mitosis and meiosis. Mitosis is termed as the asexual reproduction where the parent cell divides to form daughter cells. Meiosis causes the daughter cells to be genetically different from the parent cells. Thus, we can understand why cells are known as the structural and functional unit of life. This is because they are responsible for providing structure to the organisms and performs several functions necessary for carrying out life’s processes.

Cell Structure

The cell structure comprises individual components with specific functions essential to carry out life’s processes. These components include- cell wall, cell membrane, cytoplasm, nucleus, and cell organelles. Read on to explore more insights on cell structure and function.

Cell Membrane

  • The cell membrane supports and protects the cell. It controls the movement of substances in and out of the cells. It separates the cell from the external environment. The cell membrane is present in all the cells.
  • The cell membrane is the outer covering of a cell within which all other organelles, such as the cytoplasm and nucleus, are enclosed. It is also referred to as the plasma membrane.
  • By structure, it is a porous membrane (with pores) which permit the movement of selective substances in and out of the cell.  Besides this, the cell membrane also protects the cellular component from damage and leakage.
  • It forms the wall-like structure between two cells as well as between the cell and its surroundings.
  • Plants are immobile, so their cell structures are well-adapted to protect them from external factors. The cell wall helps to reinforce this function.

Cell Wall

  • The cell wall is the most prominent part of the plant’s cell structure. It is made up of cellulose, hemicellulose and pectin.
  • The cell wall is present exclusively in plant cells. It protects the plasma membrane and other cellular components. The cell wall is also the outermost layer of plant cells.
  • It is a rigid and stiff structure surrounding the cell membrane.
  • It provides shape and support to the cells and protects them from mechanical shocks and injuries.


  • The cytoplasm is a thick, clear, jelly-like substance present inside the cell membrane.
  • Most of the chemical reactions within a cell take place in this cytoplasm.
  • The cell organelles such as endoplasmic reticulum, vacuoles, mitochondria, ribosomes, are suspended in this cytoplasm.


  • The nucleus contains the hereditary material of the cell, the DNA.
  • It sends signals to the cells to grow, mature, divide and die.
  • The nucleus is surrounded by the nuclear envelope that separates the DNA from the rest of the cell.
  • The nucleus protects the DNA  and is an integral component of a plant’s cell structure.

Cell Organelles

Cells are composed of various cell organelles that perform certain specific functions to carry out life’s processes. The different cell organelles, along with its principal functions, are as follows:

Cell Organelle and its Functions


The nucleolus is the site of ribosome synthesis. Also, it is involved in controlling cellular activities and cellular reproduction

Nuclear membrane

The nuclear membrane protects the nucleus by forming a boundary between the nucleus and other cell organelles.


Chromosomes play a crucial role in determining the sex of an individual. Each human cells contain 23 pairs of chromosomes

Endoplasmic reticulum

The endoplasmic reticulum is involved in the transportation of substances throughout the cell. It plays a primary role in the metabolism of carbohydrates, synthesis of lipids, steroids and proteins.

Golgi Bodies

Golgi bodies are called the cell’s post office as it is involved in the transportation of materials within the cell


Ribosomes are the protein synthesisers of the cell


The mitochondrion is called “the powerhouse of the cell.” It is called so because it produces ATP – the cell’s energy currency


Lysosomes protect the cell by engulfing the foreign bodies entering the cell and helps in cell renewal. Therefore, it is known as the cell’s suicide bags


Chloroplasts are the primary organelles for photosynthesis. It contains the pigment chlorophyll


Vacuoles stores food, water, and other waste materials in the cell

Biopotential Electrodes

Biopotential electrodes is a transducer that convert the body ionic current in the body into the traditional electronic current flowing in the electrode.

Biopotential electrode should be able to conduct small current across the interface between the body and the electronic measuring circuit.

biopotential electrode used in medical field

ECG, EEG, MEG, and intracellular electrodes

Difference Between Polarizable and Non Polarizable Electrode

Polarizable and non-polarizable electrodes are the two major types of electrodes we can find in electrochemical cells. The key difference between polarizable and non polarizable electrode is that polarizable electrodes have a charge separation at the electrode-electrolyte boundary whereas non-polarizable electrodes have no charge separation at this electrode-electrolyte boundary.

Below the differences between polarizable and non polarizable electrode in more detail.

polarizable and non-polarizable electrode.