Based on what you know about organelles and enzymes and by doing some further reading, identify an organelle with a unique enzymatic activity that distinguishes it from the outside environment (outside the organelle within the cell or outside of the cell entirely). Tell us 1) its substrate(s) and product(s), whether it 2) catalyzes an ender- or exergonic reaction, and 3) plays a role in catabolism or anabolism.