What is the difference between uniport symport and antiport?
Organisms tend to experience transport of molecules or ions across their cell membrane. Transportation is divided into primary active transport and secondary active transport.
Uniport, symport, and antiport are three major integral membrane proteins that facilitate the movement of molecules across the cell membrane.
The main difference between uniport symport and antiport is that uniport moves molecules across the cell membrane independent of other molecules, symport moves two kinds of molecules in the same direction and antiport moves two kinds of molecules in opposite direction.
Comparison Table between Uniport Symport and Antiport
Uniport | Symport | Antiport |
Involve transport of a single substrate species across the cell membrane | Involve the transport of two kinds of the substrate in the same direction | Involves the transport of two kinds of the substrate in the opposite direction |
One type of molecule | Involve two types of molecules | Entails two types of molecules |
Single direction | Single direction | Both directions |
Carrier proteins | Cotransporter | Cotransporter |
Uses primary active transport | Uses secondary active transport | Uses secondary active transport |
ATP energy involved | Electrochemical gradient involves | Involve electrochemical gradient |
Channel protein is the best example | Examples are sodium or glucose symporter | Examples are Na/H antiporter |
What Is Uniport?
It is an integral membrane protein that transports a single substrate species across the cell membrane by the use of primary active transport.
Facilitate diffusion can also enhance the movement of the molecules through a diffusion gradient. These uniports work by binding to the single-molecule of the substrate.
The opening of the channel is stimulated and thus allow the free flow of specific molecules. Uniport plays a vital role in biological processes such as transmitting action potentials in neurons.
What Is Symport?
It is an integral membrane protein that involves the transportation of two types of substrate in the same direction by the use of secondary active transport.
The mechanism uses an electrochemical gradient to transport the molecules. Symport plays a vital role in the transportation of sodium and glucose across the lumen membrane of epithelial cells to be absorbed into the bloodstream.
Also, the movement of sodium, potassium, and chloride ions in the loop of Henle are good examples of symporters.
What Is Antiport?
It is a cotransporter that enhances the movement of two types of molecules in the opposite direction by the use of secondary active transport.
Examples of antiporters are N general, Na/H antiporter, and Na/Ca exchanger. They use the electrochemical gradient to enhance the mechanism.
Main Difference between Uniport Symport and Antiport
- Uniport is an integral membrane protein that transports a single substrate species across the cell membrane, symport is another integral membrane protein that transports two types of substrate in the same direction and antiport is an integral membrane protein that transports two types of substrate in the opposite direction.
- Types of molecules transported by uniport are single while both symport and antiport is two different types
- Both molecules of uniport and symport move in the same direction while molecules of antiport in the opposite direction
- Both symport and antiport uses secondary active transport while uniport uses primary active transport
- The driving force of uniport is ATP while those of symport and antiport is an electrochemical gradient
- Channel proteins are examples of uniport, Na/glucose are examples of symport and Na/H are examples of antiport
- Transporter carriers of uniport are carrier proteins, symport and antiport are cotransporters
Similarities between Uniport Symport, and Antiport
- Both are types of integral membrane proteins
- Both are transmembrane proteins
- Both use active transport for the movement of molecules or ions
- Both use unicellular energy to facilitate the movement of molecules or ions
- Both get attached to hydrophobic, electrostatic or non-covalent interactions to penetrate through the phospholipid bilayer
Frequently Asked Questions (Uniport vs Symport vs Antiport)
What is Active Transport?
It is a mechanism of transporting molecules or ions across the cell membrane against the concentration gradient by use of energy. The main types of active transport are primary and secondary transport.
What Is Primary Active Transport?
It is a type of active transport that uses ATP as the main form of cellular energy to transport molecules across the cell membrane.
What Is Secondary Active Transport?
It is the transport of molecules that depend on the electrochemical gradient of ions on either side of the plasma membrane. It is a cotransporter since it enhances the movement of two molecules simultaneously.
Does Antiport Need Energy?
Yes. The movement of molecules or ions across the cell membrane requires energy. The energy is provided by the electrochemical gradient during active transport.
Is Antiport Active or Passive Transport?
It is a cotransporter and integral membrane protein that uses secondary active transport to move two types of substrates in the same direction.
Is Symport Active Transport?
It is a secondary active transport. It involves the movement of molecules across the cell membrane by the use of energy other than ATP. The energy for pumping molecules comes from the electrochemical gradient.
Does Facilitated Diffusion Use ATP?
No. Facilitated diffusion involves the passive movement of molecules such as glucose and amino acids across the cell membrane.
Do Channel Proteins Require ATP?
No. they simply allow the flow of water and ions. Hence, they do not need any form of energy to facilitate their operation.
Does Facilitated Diffusion Use Channel Proteins?
Yes. Channel proteins help in the transportation of only water or certain types of ions. These specific protein carriers move one molecule at a time against a concentration gradient.
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Comparison Video
Summary
The main difference between uniport, symport and antiport is that uniport transport a single substrate species, symport transport two types of substrate species in the same direction while antiport transport two types of substrate species in the opposite direction.
More Sources and References
- Uniport. Wikipedia
- Antiport. Wikipedia
- Structural Features of the Uniporter/Symporter/Antiporter Superfamily. NCBI