Khan Academy Static

3A: The human body is composed of about 100 trillion cells (this is not counting your bacterial buddies, who actually outnumber your cells 10 to 1!) Your cells must speak to each other to coordinate this massive symphony of life. In this tutorial, you will learn about the molecular basis of cellular signaling that makes this vast network speedy and efficient.

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14994_Enzyme_Linked_Receptors.html

14993_G_Protein_Coupled_Receptors.html

14992_Ligand_Gated_Ion_Channels.html