PLEASE HELP!! The process, below, does what to benefit a cell? *
Prevents osmosis from causing a cell to shrivel or rupture.
Allows white blood cells to tag pathogens with antibodies.
Decreases the necessary activation energy to speed up the chemical reaction.
Increases the necessary activation energy to slow down the chemical reaction.

Decreases the necessary activation energy to speed up the chemical reaction.

Explanation:

This picture shows substrates binding to the activation site of an enzyme causing the enzyme to change shape and therfore speeds up the chemical reaction.  

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.