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 transport may be active transport by carrier proteins with an energy source, or it may be facilitated diffusion or passive transport via channels. A cell's activity depends on what biochemical reactions it may complete, and these reactions are dependent on the compounds extracted from the extracellular fluid.