Question

What is the difference between active and passive transport? Do living systems like the human body use one or both? please support your answer with textual evidence and provide examples

Answer 1

Passive transport is the transfer of molucules across membrane without the input of any energy. this usually occurs according to concentration gradients and smaller molecules are transported by this process.

Active transport requires energy (like ATP) for transport acros membrane. This occurs with larger molecules like protein and carbohydrates.

Living systems use both active and passive transport. Osmosis which occurs across membrane is a great examples of passive transport which occurs due to cncentration difference across the membrane. Absorption of nutrients lets say sugar in small intestine during digestion process is an example of active transport. Because the absorption is being made against gradient where the concentation of sugar is already high in the intestinal cells.