<span>Since charged particles cannot move across the membrane easily due to them being hydrophobic, they require a transport protein that expends energy in the form of ATP. ATP attaches onto the transport protein which changes the shape of the protein allowing ions to flow in, and it leaves a phosphate group turning into ADP.When the molecule has crossed the membrane, the phosphate group is detached from the protein.</span>
<span>Shortest side = x, Longest Side = 4x-1, third side = 18
Equation is x + (4x-1) + 18 = 42 so 5x-1 = 42-18=24 and 5x=25 so x = 5, longest side = 4(5)-1=19, third side=18
Add all 3 (5+19+18) to get 42</span>
