The tiny sacs in the presynaptic neuron that contain neurotransmitters.

small, spherically shaped sacs that bud from the ends of a Golgi apparatus.

Small membrane-bound spheres containing active molecules, for example neurotransmitters. Contents can be released after moving to edge of membrane. May contain other substances when part of transport system. Can move around the cell.

Small membrane-bound spaces in most plant and animal cells that transport macromolecules into and out of the cell and carry materials between organelles in the cell.

A small cavity in a volcanic rock that was formed by the expansion of escaping gas bubbles.

Swollen lipid filled bodies produced in plant root cells by most, but not all endomycorrhizas. Used for storage.

Small "bubbles" of lipid within a cell, used for the transport of materials within the cell and between the cell membrane and the outside environment.

Open holes in igneous rock formed by the preservation of bubbles in magma as the magma cools into solid rock.