Proteinoplasts (sometimes called proteoplasts, aleuroplasts, and aleuronaplasts) are specialized organelles found only in plant cells. Proteinoplasts belong to a broad category of organelles known as plastids. Plastids are specialized double-membrane organelles found in plant cells.
Plant cells contain proteinoplasts, also known as proteoplasts, aleuroplasts, and aleuronaplasts. These organelles are part of a larger group called plastids, which are double-membraned structures found within plant cells.