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 two carrier proteins on the left are using ATP to move sodium out of the cell against the concentration gradient. The proteins on the right are using secondary active transport to move potassium into the cell. Active transport is the movement of a substance across a membrane against its concentration gradient. This is usually to accumulate high concentrations of molecules that a cell needs, such as glucose or amino acids.