The Space External to the Outermost Structure of a Cell. For Cells Without External Protective or External Encapsulating Structures This Refers to Space Outside of the Plasma Membrane. This Term Covers the Host Cell Environment Outside an Intracellular Parasite.
A Postsynaptic Membrane That Is Part of Another Organism I.e. a Secondary Organism with Which the First Organism Is Interacting. a Postsynaptic Membrane Is a Specialized Area of Membrane Facing the Presynaptic Membrane On the Tip of the Nerve Ending and Separated From It by a Minute Cleft (the Synaptic Cleft). Neurotransmitters Transmit the Signal Across the Synaptic Cleft to the Postsynaptic Membrane.