What Is Active Transport?
Active transport is the movement of molecules across a membrane from a region of their lower concentration to a region of their higher concentration against the concentration gradient. Active transport uses cellular energy to move molecules against a concentration gradient.
There are two types of active transport: Primary and Secondary active transport. Primary active transport uses energy (ATP) whereas, secondary active transport uses electrochemical gradient. An example of active transport in humans is the uptake of glucose in the intestine and in plants is uptake of mineral ions.
What You Need To Know About Active Transport
- Active transport can be defined as movement of molecules across the cell membrane, pumping the molecules against the concentration between ATP (energy).
- In active transport system, the molecules move from the region of high concentration to a region of low concentration. What this means is that they move against the concentration gradient and are pumped in that direction.
- Active transport is a unidirectional and rapid process .
- Active transport usually transports insoluble heavy and complex particles such as complex sugars, large cells, protein molecules, lipids amino acid, ions etc.
- Examples of similar processes to active transport include phagocytosis, endocytosis, exocytosis, pinocytosis, sodium/potassium pump, secretion of a substance into the bloodstream.
- Examples of active transport include a sodium/potassium pump, glucose selection in the intestines and the uptake of mineral ions by plant roots.
- Active transport utilizes cellular energy in the form of ATP.
- Active transport is required for the entrance of large, insoluble molecules into the cell.
The main roles of active transport include:
- Supply nutrition and food against the concentration gradient.
- Supply nutrition inside the body of the cell.
- Forcefully move waste outside the cell body.
What Is Passive Transport?
Passive transport is the movement of molecules, ions and substances across a cell membrane and against a concentration gradient without the use of energy. Unlike active transport that depends on energy input, passive transport depends only on permeability of the cell membrane, which in turn depends on the structure of lipids and proteins.
Examples of processes that work on the same principle as passive transport include simple diffusion, filtration, osmosis and facilitated diffusion.
What You Need To Know About Passive Transport
- Passive transport can be described as the movement of molecules within and across the cell membrane and throughout the concentration gradient, without using energy (ATP).
- In passive transport the molecules move from a region of low concentration to a region of high concentration. What this means is that, molecules move along the concentration gradient and in the downward direction.
- Passive transport is bidirectional process.
- Passive transport usually transports any kind of small particles that are soluble and are dissolved in the blood stream such as hormones, monosaccharide, oxygen, carbon dioxide, water etc.
- Examples of similar processes to passive transport include diffusion, osmosis and facilitated diffusion.
- Passive transport occurs in the kidneys and liver and in the alveoli of the lungs when they exchange oxygen and carbon dioxide.
- Passive transport does not require cellular energy.
- Passive transport allows the maintenance of a delicate balance between the cytosol and extracellular fluid.
The main roles of passive transport include:
- Maintain equilibrium of gases, nutrients and liquids inside the body.
- Regulates the flow of water molecules and extracellular fluids.
- To stop Net diffusion after equilibrium is established.
Similarities Between Active Transport And Passive Transport
- Both are mechanisms of movement for substances in and out of the cell.
- Both of these transport mechanisms make use of ion channels to push ions in and out of the cell along the cell membrane.
- Just like other mechanisms that are executed in the cell, both passive and active transport basically strive towards ensuring that there is homeostasis and stability maintained in the cell and as a result , in the entire body.
Also Read: Difference Between Simple Diffusion And Facilitated Diffusion
The Difference Between Active Transport And Passive Transport In Tabular Form
| Basis of Comparison | Active Transport | Passive Transport |
| Description | Active transport can be defined as movement of molecules across the cell membrane, pumping the molecules against the concentration between ATP (energy). | Passive transport can be described as the movement of molecules within and across the cell membrane and throughout the concentration gradient, without using energy (ATP). |
| Movement of Molecules | The molecules move from the region of high concentration to a region of low concentration. What this means is that they move against the concentration gradient and are pumped in that direction. | The molecules move from a region of low concentration to a region of high concentration. What this means is that, molecules move along the concentration gradient and in the downward direction. |
| Description of the Process | It is a unidirectional and rapid process. | It is a bidirectional process. |
| Types of Particles | Active transport usually transports insoluble heavy and complex particles such as complex sugars, large cells, protein molecules, lipids amino acid, ions etc. | Passive transport usually transports any kind of small particles that are soluble and are dissolved in the blood stream such as hormones, monosaccharide, oxygen, carbon dioxide, water etc. |
| Main Roles | The main roles of active transport include: Supply nutrition and food against the concentration gradient.Supply nutrition inside the body of the cell.Forcefully move waste outside the cell body. | The main roles of passive transport include: Maintain equilibrium of gases, nutrients and liquids inside the body.Regulates the flow of water molecules and extracellular fluids.To stop Net diffusion after equilibrium is established. |
| Similar types of the same Process | Examples of similar processes to active transport include phagocytosis, endocytosis, exocytosis, pinocytosis, sodium/potassium pump, secretion of a substance into the bloodstream. | Examples of similar process to passive transport include diffusion, osmosis and facilitated diffusion. |
| Examples | Examples of active transport include a sodium/potassium pump, glucose selection in the intestines and the uptake of mineral ions by plant roots. | Passive transport occurs in the kidneys and liver and in the alveoli of the lungs when they exchange oxygen and carbon dioxide. |
| ATP (Energy Usage) | Utilizes cellular energy in the form of ATP. | Does not require cellular energy. |
| Importance | It is required for the entrance of large, insoluble molecules into the cell. | Allows the maintenance of a delicate balance between the cytosol and extracellular fluid. |
Summary
Also Read: Difference Between Transpiration And Guttation
Active transport can be defined as movement of molecules across the cell membrane, pumping the molecules against the concentration between ATP (energy). In contrast, Passive transport can be described as the movement of molecules within and across the cell membrane and throughout the concentration gradient, without using energy (ATP).