The main difference between active transport and group translocation is that active transport releases exactly the molecules that were taken up from the medium. The molecules absorbed from the medium, on the other hand, change during the transport process. In addition, active transport uses chemical energy from ATP or electrochemical gradients for transport, while group translocation uses energy from organic compounds to transport molecules.
Active transport and group translocation are two types of membrane transport mechanisms in which different molecules of the medium through the cell membrane into the added cytoplasm are . In general, group translocation is a type of active transport.
Key areas covered
1. What is active transport - definition, mechanism, meaning 2. What is group translocation - definition, mechanism, meaning 3. What are the similarities between active transport and group translocation - overview of the common features 4. What is the difference between active transport and Group Translocation - Comparison of Key Differences
key terms
Active Transport, ATP, Group Translocation, Primary Active Transport, PTS System, Secondary Active Transport
What is active transportation?
Active transport is the mechanism of transporting molecules across the plasma membrane against the concentration gradient using energy. In general, transmembrane carrier proteins participate in active transport. In addition, two types of active transport mechanisms can occur in a cell; they are the primary active transport and the secondary active transport.
Primary active transport
The primary active transport uses metabolic energy in the form of ATP to move molecules across the membrane. Therefore, carrier proteins that transport molecules by primary active transport are always coupled with ATPase. The best-known example of primary active transport is the sodium-potassium pump, which carries three Na + ions into the cell while moving two K + ions out of the cell. Thus, the sodium-potassium pump helps maintain cell potential.
Figure 1: Sodium-Potassium Pump
Secondary active transport
On the other hand, the secondary active transport relies on the electrochemical gradient of the ions on both sides of the plasma membrane to transport molecules. That means; it uses the energy released by transporting one type of molecule through its concentration gradient to transport another type of molecule against the concentration gradient. Therefore, transmembrane proteins involved in secondary active transport are cotransporters . Basically, the two types of cotransporters are symporters and antiporters. Of which symporters transport both molecules in the same direction. The sodium-glucose cotransporter is also a kind of symporter. In the meantime, Antiporter transport the two types of molecules in opposite directions. The sodium-calcium exchanger is an example of an antiporter.
Figure 2: Carrier
Apart from that, the ABC system (ATP-binding cassette) in Gram-negative bacteria uses substrate-specific binding proteins in the bacterial periplasm to transport molecules.
What is group translocation?
Group translocation is a unique type of active transport that uses energy from the high-energy organic compounds other than ATP. However, it differs from other cotransporters and the ABC system in that molecules transported by group translocation undergo chemical modifications. In general, one of the most common examples of such group translocation is the phosphotransferase (PTS) system in bacteria. Here it is responsible for the absorption of sugar and uses energy from phosphoenolpyruvate (PEP), an energy-rich molecule. Usually it is a multi-component system that uses enzymes in the plasma membrane.
Figure 3: PTS system in bacteria
In addition, after translocation through the cell membrane, the transported molecules undergo modifications during group translocation. Normally in the PTS system a phosphate group is transferred from PEP to the transporting sugar. In addition, sugars that are translocated include glucose, fructose, mannose, and cellobiose.
Similarities Between Active Transport and Group Translocation
- Active transport and group translocation are two processes of membrane transport mechanisms .
- They are responsible for the transport of molecules from the medium through the cell membrane into the cytoplasm.
- They also transport molecules against a concentration gradient by using cellular energy with the help of transport proteins.
- Both mechanisms are important for the uptake of nutrients and other ions into the cell.
Difference between active transport and group translocation
definition
Active transport refers to the movement of ions or molecules across a cell membrane into an area of higher concentration, assisted by enzymes and requiring energy. Group translocation, on the other hand, refers to a mechanism that is often used for the transport of sugars across bacterial membranes and possibly those of some higher cells.
Types of transporter proteins
The four types of active transport transport proteins are antiporters, symporters, ATP-binding cassette systems, and group translocation. Meanwhile, the enzymes of the plasma membrane, such as the phosphotransferase (PTS) system, take part in the group translocation.
Energy type
Active transport uses energy from ATP or electrochemical gradients, while group translocation uses the breakdown of high energy compounds like PEP.
Types of molecules transported
Active transport moves glucose, amino acids, and ions into the cytoplasm, while group translocation moves many sugars such as glucose, mannose, fructose, and cellobiose into bacteria.
Changes
Active transport releases exactly the same molecules that were taken up from the medium, while molecules that were taken up from the medium undergo modifications during the transport process.
diploma
Active transport is a type of membrane transport mechanism that transports ions, glucose, and amino acids across the cell membrane into the cell. It uses either ATP in primary active transport or an electrochemical gradient in secondary active transport. On the other hand, group translocation is a type of active transport that uses the energy from PEP to move sugar mainly in bacteria. However, both active transport and group translocation move molecules into the cytoplasm against a concentration gradient. Hence, the main difference between active transport and group translocation is the nature of the energy, mechanisms and molecules transported.
References:
1. "Transport through the cell membrane | Boundless microbiology. ” Lumen , available here.
Image courtesy:
1. “Scheme sodium-potassium-pump-de” by LadyofHats Mariana Ruiz Villarreal - own work. (Public Domain) via Commons Wikimedia 2. “Porters” By Lupask - Own work (Public Domain) via Commons Wikimedia 3. “Phosphotransferase System” By Yikrazuul - Own work; ISBN 978-3-13-444608-1 ; P. 505 ( CC BY-SA 3.0 ) via Commons Wikimedia
