Outside of the U.S., many cruise lines do not have automatic tipping policies, says McDaniel, as other countriesâ tipping customs are different than ours (and thus their staff is paid differently), so it may pay to look at cruises leaving from other countries and then look at their âsuggestedâ tipping options.
Best Answer: Active transport is the mediated process of moving particles across a biological membrane against a concentration gradient. If the process uses chemical energy, such as from adenosine triphosphate (ATP), it is termed primary active transport. Secondary active transport involves the use of an electrochemical gradient.
The other process is referred to as active transport because it requires the cell to expend chemical energy, typically adenosine triphosphate, commonly called ATP. Active transport occurs when a solute must pass through the cell membrane against its concentration gradient. A good analogy is that this is like pushing the water that fell over a waterfall, back up the river to the falls above. It takes a lot of energy for the cell to do this.