What are membrane bound proteins that enable the cell to sense it’s surroundings ?

What is the problem in this article? what solution does the article propose?

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers

The solution inside a plant cell is approximately a 1% saline solution and a 21% nacl solution the ,cytoplasm of a plant cell will