The passive and active forms of transportation of molecules across a membrane play an important biological role for all living species.
Osmosis and active transport are the two types of processes in which charged particles move across a membrane. These processes are crucial for maintaining the water balance and homeostasis in the body.
Osmosis vs Active Transport
The difference between osmosis and active transport is that osmosis is a passive form of transportation of molecules. Osmosis occurs only when a semi-permeable membrane is present.
It aims at equalizing the concentration on both ends of the membrane. On the other hand, Active transport is an active form of transportation of molecules. It does not need a semi-permeable membrane.
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In osmosis, water particles move from a higher to a level of lower concentration. This process ensures that it equalizes the concentration of solute on both ends. Osmosis makes sure there is equilibrium.
There is a net amount of pressure needed for molecules to move across the semi-permeable membrane. This net amount of pressure is known as Osmotic pressure.
In Active transport, particles move from lower to an extent of the higher congregation. Active transport gets used by cells to collect much-required particles of amino acids and glucose molecules.
When ATP gets synthesized, the process is called primary active transport. Active transport uses energy that gets released during respiration.
|Parameters of Comparison||Osmosis||Active Transport|
|Concentration||Molecules move from higher to Lower Concentration||Particles move from lower to higher concentrations.|
|Movement||In osmosis, water molecules move through a semi-permeable membrane.||In Active transport, solutes move across a membrane.|
|Energy||Osmosis does not require energy||Active transport requires energy through respiration.|
|Concentration Gradient||In osmosis, molecules move down the gradient.||In Active transport, solute moves against the gradient.|
|Equilibrium||Osmosis maintains the equilibrium.||Active transport does not maintain equilibrium.|
What is Osmosis?
The terminology osmoses (now osmosis) was introduced by a British chemist, Thomas Graham, in 1854. In biology, the motion of water particles across a relatively porous layer is osmosis.
In osmosis, the motion is always from a solution with an elevated concentration of water particles to a lower area of water particles.
The partially permeable membrane or selectively permeable membrane allows selective molecules to pass through it. The water molecules pass in both areas.
What is a higher and lower concentration of water?
The higher water saturation in osmosis implies a dilute sucrose solution, and the lower concentration suggests a concentrated sucrose solution.
Enclosing the plant cell by a solution that contains a higher concentration of water molecular, the water enters the cell causes the cell to be turgid (firm).
Turgid helps the stem to stay upright. Enclosing the plant cell with a solution that contains a lower concentration of water molecules, the water leaves the cell and becomes flaccid(soft).
When the stem cells become slack, it decreases the turgor pressure of the stem and causes wilting. If the concentration is similar, there is a net flow of water around the cell through the partially permeable membrane.
Osmosis in animal cells:
Osmosis is the primary means of transporting water into the cells. Osmosis is of primary importance in the living organism. It influences the distribution of nutrients and releases metabolic waste such as urea.
Osmosis is essential for water and mineral absorption in plants, animals, and other living organisms. If you dip your fingers for long in the water, the finger gets pruned. It is an osmosis reaction as the akin absorb water and get expanded.
What is Active transport?
In Active transport, the solutes go against a congregation gradient. For Active transport to occur smoothly energy is essential.
Solutes go across an extent of minor concentration to an extent of inflated concentration. It is a process utilized by cells to gather necessary molecules.
German physiologist, Emil du Bois-Reymond put forward the feasibility of the fluctuations of molecule’s movement over a membrane in the year 1848.
In 1948 Rosenberg explained the process of active transport. He said it depends on energy. Robert Krane, an American biochemist, played a pivotal role in the research of Active transport.
When the entire process gets pushed by adenosine triphosphate (ATP), it can be labeled Primary active transport. When an electrochemical gradient gets optimized for energy, the process is termed secondary active transport.
What is Primary Active Transport?
Primary active transport is even termed as the action of direct active transport. The activity of direct active transport makes use of cellular power to progress the particles beyond a layer.
Some of the solutes that get transferred across the membrane comprise charged particles like metal ions. These charged particles are necessary to get spread across the body.
Ion pumps come to pass to move the particles across the membrane. There is a direct coupling of ATP in primary active transport.
What is Secondary Active Transport?
Cotransport or coupled transport are termed secondary active transport. Energy is consumed as a source of force to move molecules across the membrane.
ATP coupling is not present in Secondary active transport. The Galvanic potential difference gradient is responsible for the pumping of ions. The energy produced by pumping ions gets used as the source of energy.
Main Differences Between Osmosis and Active Transport
- The factors responsible for osmosis are osmotic pressure and osmotic gradient. The factors responsible for active transport are ATP and electrochemical gradient.
- Osmosis is of two types, reverse and forward osmosis. Primary and Secondary active transport is under active transport.
- Osmosis does not require metabolic energy. Active transport requires metabolic energy.
- Osmosis maintains equilibrium. No equilibrium gets maintained in active transport.
- Osmosis occurs through a semi-permeable membrane. Active transport does not need a semi-permeable membrane.
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Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.