One Important Feature of the Transport Proteins Used to Package

question 29

Multiple Choice

One important feature of the transport proteins used to package neurotransmitters into vesicles is that

• A) they often have low specificity and may transport more than one type of neurotransmitter.
• B) one type of protein transports the low-molecular-weight transmitters, and a second type transports neuropeptides.
• C) they are usually saturated and serve as the rate-limiting factor for the availability of vesicles.
• D) they may also be present in the cell membrane and transport neurotransmitters directly into the extracellular space.
• E) they are highly efficient so that little neurotransmitter can be found outside of vesicles.