Active Transport vs Passive Transport

As minute as they are, cells in the body carry some very important processes deep within. These processes are all vital to the overall growth and development of every organism, may it be an animal or a plant. But every internal process must have some unique mechanisms done to make it successful. In this regard, nutrients, chemicals and other substances are flowing to and fro the cells with the use of certain transport systems. These transport mechanisms are classified into two, namely active and passive transport systems.

In the simplest terms, active transport is termed ‘active’ because of the inclusion of one vital component and that is the use of energy. This energy is being utilized by the cell, in the form of ATP (Adenosine Triphosphate) for it to be able to move most substances in and out of its cellular membranes. On the contrary, passive transport is regarded as such because it is just a plain old ‘passive’ mechanism. It does not use any energy (ATP) from the cell for it to carry out the said processes.

Another distinct characteristic that separates active from passive transport system is the difference in the concentration gradients. It must be made known that the concentration of substances that are partitioned by cell membranes are relatively different. For example, the inside of the cell has a concentration gradient that is higher (more concentrated) than the outside of the cell (less concentrated) or it can also be the other way around depending on various biological factors. Hence, in active transport, it tries to achieve a more difficult task of opposing the concentration gradient. If the cell wants to transport certain substances towards itself (in this situation, it so happens to be more concentrated) then it needs much energy for its protein or sodium pumps to operate and transfer the said substances.

In the case of passive transport, it is not against but along the concentration gradient. Because the cell sees that the same ions or molecules can be transferred to the other side immediately due to a ‘favorable’ concentration gradient, it no longer expends any energy. The word ‘favorable’ simply means that it follows the rules of normal diffusion. When the substances from the more concentrated internal environment of the cell are to be transported outside, that is for example the outside happens to be less concentrated, then the substances can easily flow out.

In brief, active and passive transport differ because:
1.Active transport makes use of energy in the form of ATP whereas passive transport does not utilize any.
2.Active transport involves the transfer of molecules or ions against a concentration gradient whereas passive transport is the transfer along a concentration gradient.

Sharing is caring!