Question

Which of the following is NOT a characteristic of active transport?

1) sensitive to metabolic poisons
2) exclusively move one molecule at a time in a unidirectional manner
3) can be coupled with passive transport to generate the energy necessary for active transport
4) can work as symports or antiports
5) all of the above

Answer 1

Active transport is a mechanism that moves substances against their concentration gradient and requires energy. It can work as symports or antiports and is sensitive to metabolic poisons. However, it is not limited to moving one molecule at a time.

Step-by-step explanation:

Active transport is a mechanism in which substances are transported against their concentration gradient, requiring the expenditure of energy. It is characterized by the use of carrier proteins or pumps to facilitate movement. One characteristic of active transport is that it can work as symports or antiports, transporting two different ions or molecules in the same or opposite directions, respectively. Another characteristic is that it is sensitive to metabolic poisons that interfere with the supply of ATP, which is needed for active transport. However, active transport is not exclusively limited to moving one molecule at a time in a unidirectional manner. It can move multiple molecules or ions simultaneously.