Enzymes are usually proteins. based on what you know about how proteins are made, how would a cell make more of a particular enzyme in order to increase the concentration of that particular enzyme?

Cell signalling pathways are used to maintain homeostasis. Enzymes are normally present in adequate concentrations but whenever the need for a particular enzyme or protein arises, cell signalling is used.

Signal is sent to that particular cell, the process of genetic expression is activated. A gene that codes for that particular protein(enzyme of interest) goes through transcription, where that genes DNA is copied to make a messenger RNAmolecule, which is further expressed by a process called Protein expression. Lastly, transported to that particular area where it is needed.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.