(b): Photosynthetic bacteria have chromatophores which are membrane bound vesicular structures which are extensions of cytoplasmic membrane. They contain photosynthetic pigments along with enzymes and electron carriers for photosynthetic phosphorylation. These pigments are bacteriochlorophyll and bacteriophaeophytin. Leucoplasts, chloroplasts and chromoplasts are different types of plasids which occur in plastids and some protistans.