Apparently it is ATP as deduced from the last line of text and no model to refer to.
Answer:
the answer is kick the hi what you doing
Facilitated diffusion of substances crossing the cell (plasma) membrane takes place with the help of proteins such as channel proteins and carrier proteins.
I cant see the pictures right take another picture and maybe i will be able to help you
Covalent bonds are the strongest chemical bonds. They are chemical bonds in which electrons are shared between atoms.
