Some substances can go directly through the cell membrane, but other larger ones either go throuh channels or attach to a protein that aids them into the cell.
The watery environment of the cytoplasm.
circulatory system
Glial cells
Glial
words
Transport
The blood circulatory system transports cells and dissolved substances to and from the organs designed to deal with filtering out such things.
ATP and Transport Proteins
Active Transport
A fluid
Transport Proteins
Generally, cells derive their energy from ATP (in their phosphate bond).
words
Transport
the transport of dissolved substances into cells to be used by the cells is
When transporting substances from low to high concentration, or when transporting substances too large to pass through the membrane without assistance from a transport protein.
The blood circulatory system transports cells and dissolved substances to and from the organs designed to deal with filtering out such things.
oxygen transport to cell & carbondioxide away from cells.
ATP and Transport Proteins
Active Transport
No, they don't. They "instruct" other substances in the cells to do that job, they never do any work but they are the brains in cells.