The cell is responsible for all the activities that occur inside our bodies. It is known as the basic unit of life. Important tasks are performed by specialized cells, which is required for the growth and development of the body. An essential transport system is used to transport the chemicals, nutrients, and other substances to other cells of the body. This transport mechanism is of two types, like active and passive transport. In this article, we will see the Difference Between Active and Passive Transport.
Active transport uses energy for the mobility of the molecules in and out of the cellular membranes and therefore remains active, whereas in passive transport the molecules do not use any energy for their movements and so they are known as passive. The main aim of these transport systems is to carry essential molecules and ions across the cellular membrane.
The outer layer is made up of the phospholipid bilayer. It maintains the homeostasis of the cell and checks the entry of the substances. The entry of the molecules is supported by the specialized proteins along with the semi-permeable membrane.
Difference Between Active And Passive Transport
| Character | Active Transport | Passive Transport |
| Definition | In Active transport the molecules are moved across the cell membrane, pumping the molecules against the concentration gradient using ATP (energy). | In Passive transport, the molecules are moved within and across the cell membrane and thus transporting it through the concentration gradient, without using ATP (energy). |
| Energy | Active transport requires cellular energy. | Passive transport does not require any cellular energy. |
| Circulation | The circulation in this process is from a region of lower concentration to a region of higher concentration. | The circulation in this process is from a region of higher concentration to a region of lower concentration. |
| Process | It is a dynamic and rapid process. | It is a physical and comparatively slow process. |
| Aim | The main aim is to transport all molecules such as proteins, large cells, complex sugars, ions, etc. | The main aim is to transport all soluble molecules, including oxygen, water, carbon dioxide, lipids, sex hormones, etc. |
| Protein | The active transport, carrier proteins are required. | The passive transport, carrier proteins are not required. |
| Direction | Transportation is only in one direction. | Transportation is bidirectional. |
| Selective | Active transport is highly selective. | Passive transport is partly non-selective. |
| Temperature | It is influenced by temperature. | It is not influenced by temperature. |
| Metabolic inhibitors | Active transportation is influenced by metabolic inhibitors. | Passive transportation is not influenced by metabolic inhibitors. |
| Types | Exocytosis, Endocytosis, sodium-potassium pump. | Osmosis, diffusion, and facilitated diffusion. |
Active Transport
Definition
In the active transport, the molecules are carried from the lower concentration gradient region to the upper concentration gradient region. Due to the unidirectional process, the molecules are pump in the upward direction, and therefore this process requires energy in the form of Adenosine triphosphate.
Active transport helps in the transportation of larger cells and molecules like proteins, lipids, sugars, etc. It is classified into two categories
- Primary active transport
- Secondary active transport
Primary active transport
The primary active transport, identify the substance which is to be transported with the help of the proteins present in trans-membrane and then by using chemical energy ATP, pump these molecules to their particular place.
For example, the Sodium/potassium pump is transported with the help of an active primary transport process. In this process, the transmembrane proteins present on the cell membrane recognizes the extracellular fluid requirement of the cell and pumped the molecules to be transported. The energy for this mobility of the molecules is provided by the hydrolysis of ATP. Thus, the three sodium ions are moved out of the cell, and two potassium ions are pushed into the cells.
Secondary active transport
The secondary active transport, help in the movement of the ions with the help of the pore-forming proteins. In this process, the channels are formed in the cell membrane, by using the electromagnetic gradient. While the secondary active transport helps in the movement of the other molecules against the concentration gradient. This gradient is known as cotransporters.
Cotransporters are categorized into two types:
- Symporters
- Antiporters
In symporters, the solute and ions move in the same direction across the cell membrane. While in antiporters the ions and solute move in the opposite direction. In antiporters, the ions move along with the concentration gradient, and the solute moves against the gradient. For example, Sodium/calcium exchanger.
Passive Transport
Definition
In passive transport, the molecules are carried from the higher concentration gradient region to the region of the lower concentration gradient region. In this process, the molecules are bi-directional. The molecules move in the downward direction and there is no requirement of energy, due to the lack of resistance. The main motive of passive transport is to maintain the equilibrium in the concentration. This transportation is found in the liver, kidney, and in lungs of a body.
Passive transport is further classified into four categories;
- Osmosis
- Diffusion
- Facilitated diffusion
- Filtration
Osmosis occurs when the water molecules more, through a selectively permeable membrane. When the molecules move from the more concentrated solution to the less concentrated solution through the permeable membrane it is said to be the Diffusion process. Even the proteins found in the cell membrane help for the quick and swift movement of the molecules. Such movements are known as facilitated diffusion. Filtration is known as the movement of molecules across the concentration gradient.
Conclusion
This article, conclude the function and importance of the two types of important transport system present in the body and how they are responsible for the movement of molecules and ions. This transport system works, with the aim of fulfilling the requirements and maintaining the equilibrium of the cell and the body.
