The basic unit of life is called a cell and It is in charge of the activities that take place inside the body. The various nutrients must be transported to the various cells of the body, which necessitates the use of a transportation system. The mechanism of transport can be categorized into two types Active and Passive Transport. These are the two important biological terms that help in the movement of oxygen, water, and other elements or molecules to the cells along with the elimination of the waste products.
Summary
Active vs Passive Transport
The main difference between active and passive transport is that the ATP – Adenosine triphosphate molecule is necessary to transport molecules across the cell membrane against a concentration gradient from lower to higher regions, whereas passive transport transfers ions and biochemicals across the cell membrane without the use of energy. They work on the same purpose or goals but with different movements.
Active transport is the process by which various macromolecules such as carbohydrates, proteins, lipids, glucose, and others are transported across the cell membrane across a concentration gradient from an area of low concentration to a region of greater concentration. Its transportation is only in one direction and it is influenced by temperature and metabolic inhibitors.
Passive transport is defined as the movement of molecules from a greater concentration to a lower concentration across the cell membrane without the expenditure of cellular energy. It diffuses out the waste like carbon dioxide, water, etc, and does not influence by metabolic inhibitors.
Comparison Table Between Active and Passive Transport
| Parameters of Comparison | Active Transport | Passive Transport |
| Definition | All molecules, including proteins, minerals, ions, and others, must be transported from the lower to the upper regions, which necessitates the use of energy. | All soluble molecules, including oxygen, carbon dioxide, lipids, water, and others, flow from upper concentrations to lower concentrations without requiring energy. |
| Direction | It transports only in one direction. | It transports bi-directional. |
| Process | Rapid and dynamic. | Slow and physical. |
| Types | There are three categories of active transportation. | There are four types of passive transportation. |
| Functions | Its role is to convey chemicals and ions through the cell membrane and is highly selective. | It’s partly non-selective and used to keep cells stable, both inside and outside of them. |
What is Active Transport?
Active transport occurs when a protein pump uses ATP to move molecules or ions from a low concentrations region to the region of greater concentrations against a gradient with the help of external energy. It is such as highly selective and dynamic process. It transports the macromolecules like carbohydrates, proteins, ions, etc in one direction only and it is highly influenced by metabolic inhibitors. This process does not work when the oxygen content gets reduced. It is divided into two categories:
- Primary Active Transport: It is the method through which ATP uses energy to transport molecules or proteins across the cell membrane across a concentration gradient. The sodium ions migrated outside of the cell, whereas the potassium ions flowed within.
- Secondary Active Transport: Here the proteins of the cell membrane are operated by an electrochemical gradient and there is the simultaneous movement of the protein and ions across the cell membrane that can be seen with the secondary active transport.
What is Passive Transport?
Passive transport is the transfer of molecules or ions across the cell membrane without the application of external energy from an area of greater concentration to a region of lower concentration. It is a non-selective and a kind of slow process that transports in bi-directional as the ions travel downwards without any requirements of carrier or membrane proteins.
It is important as it helps in maintaining balance among cells as it excretes carbon dioxide and other harmful wastes from the body. Through the process, soluble materials like carbon dioxide, monosaccharide sugars, oxygen, hormones, etc are transported to the cells. It is of four types:
- Simple Diffusion: the difference in the concentration of two areas is known as concentration gradient and it is the process where the substance move in and out of the cells. The process continues until the gradient neutralizes and the diffusion takes place in liquid or gas form as the particles move randomly from one place to another.
- Facilitated Diffusion: it is the passive transport where the large and insoluble substance transports across the cell membrane through specific transmembrane integral protein. It does not require any cellular or external energy and in this diffusion the transmembrane protein is important.
- Filtration: it is the process where the selective absorption of nutrients takes place inside the body that is, filtration is the process of separating the solids from liquids and gases. It doesn’t require energy and takes place along the concentration gradient.
- Osmosis: To maintain the balance of the other substances the water and other molecules pass through a selectively permeable membrane this process is called osmosis. It requires energy and is affected by the concentration gradient and temperature.
Main Differences Between Active and Passive Transport
- ATP is used to push molecules against a concentration gradient through active transport with the help of cellular energy whereas, Without the application of energy, passive transport carries the molecules along the concentration gradient.
- Active transport necessitates the use of energy to transfer biochemicals from a low-concentration area to a higher-concentration area, on the contrary, Passive transport does not require energy as it moves the biochemicals from a higher concentration region to a lower concentration region.
- Active transportation is a crucial and quick procedure, whereas passive transportation is a physically demanding and long one.
- Active transport is only one-directional and temperature affected whereas passive transport is bi-directional and does not affect by temperature.
- Active transport function is to transport the ions and molecules to the cell membrane, on the other hand, passive transport maintains the equilibrium within or outside the cell.
Conclusion
There are two methods of transporting the molecules across the cell membrane are the active and passive transport. In the process of active transport, there is the use of cellular energy that transports the molecules and the ions from the lower to higher concentration against the concentration gradient. ATP is used as a form of energy. Passive diffusion makes travel the molecules inside or outside the cell membrane to excrete the carbon dioxide and the other harmful substances without the use of ATP. The key difference between their process is the mechanisms of transporting the molecules across the membrane.