part of part of in taxon synaptic vesicle This term should not be confused with GO:0097547 'synaptic vesicle protein transport vesicle'. STVs and synaptic vesicles differ both functionally and morphologically. Functionally, STVs are transport vesicles that deliver synaptic vesicle proteins to synapses, while synaptic vesicles are responsible for transmitter release at synapses. Morphologically, synaptic vesicles are very homogeneous, while STVs are very heterogeneous in size and shape. STVs might be a precursor for synaptic vesicles. exocytic vesicle presynapse Eumetazoa