The chlorophylls are green pigments responsible for the color of leafy vegetables and some fruits. In green leaves, the chlorophyll is broken down during senescence and the green color tends to disappear. In many fruits, chlorophyll is present in the unripe state and gradually disappears as the yellow and red carotenoids take over during ripening. In plants, chlorophyll is isolated in the chloroplastids. These are microscopic particles consisting of even smaller units, called grana, which are usually less than one micrometer in size and at the limit of resolution of the light microscope. The grana are highly structured and contain laminae between which the chlorophyll molecules are positioned.