Active Transport vs Passive Transport
Active transport and passive transport refer to the different movements of molecules through a concentration gradient. Concentration gradient is a gradual change in concentration of particles in a solution between two regions and gradient results when there is an unequal distribution of ions across the cell membrane. So when movements of particles are against the concentration gradient it is an active transport, and if it’s towards the concentration gradient, it is a passive transport.
To elaborate more, consider the food we eat. We eat to give nourishment to our body. The nutrients from the food we eat will then be transported to our cells, to nourish them. And so the transport system comes into place. Since the concentration gradients surrounding the cells differ from that of the inside of the cells, the transport system also varies.
Considering that the concentration gradient is higher inside the cell membrane compared to the outside, when molecules are transported to the cells, it is moving against the concentration gradient, and so uses the active transport. And if cells will transport molecules from inside out, it will be moving towards the concentration gradient and so uses a passive transport system.
Another difference between active and passive transport is that an active transport requires more energy which is usually sourced from Adenosine Triphosphate (ATP) for moving particles from lower concentration gradient to a concentration of higher gradient. This Passive transport has no energy requirement since there is a automatic movement of particles from higher concentration gradient to lower concentration gradient.
Apparently, the active and passive transports have major roles in transporting molecules or particles to anywhere it is needed. These transport systems are not limited to the human body, in fact, it observed in the biological composition of plants and animals. The movements of air from warm to cold (passive) or cold to warm (active) regions also uses transport system.
• Active transport system refers to the movements of particles against the concentration gradient and uses more energy to move from lower to higher concentration gradients.
• Passive transport system refers to movements of particles towards the concentration gradient and requires no energy to move from higher to lower concentration gradients.