Question

1. what is the main difference between passive transport and active transport of materials across a cell membrane? 26. what are the two types of active transport, and how do they differ?

Explanation:

For question 25, passive transport moves materials along a concentration gradient without energy input, while active transport moves materials against a concentration gradient and requires energy (usually ATP). For question 26, the two types of active transport are primary and secondary. Primary active transport directly uses energy (e.g., ATP hydrolysis) to move substances across the membrane. Secondary active transport uses the electrochemical gradient established by primary active transport to move other substances. It couples the movement of one substance down its gradient to the movement of another against its gradient.

Answer:

1. Passive transport occurs along a concentration gradient without energy; active transport occurs against a concentration gradient and requires energy.
2. The two types are primary and secondary. Primary uses direct energy (e.g., ATP); secondary uses an established electrochemical gradient from primary active - transport to move substances.