<span>Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentration—in the direction against some gradient or other obstructing factor (often a concentration gradient).</span>
At higher concentrations, it catalyzes the collisions. think of it like a glow-stick. the smaller ones aren't a bright because less chemicals are inside the tube, but large glow-sticks are brighter, and has more chemicals contained in the tube. the correct answer is 3, the catalyst answer. <span>At higher concentrations, product molecules are able to catalyze the reaction.
hope this helped. good luck!
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A system is a group of organs that work together and provide an organism with an advantage for survival. It is the most complex organization in your body and the final level of the progression from cells to tissues to organs and then systems.