Lysosomes are small organelles that are produced by the Golgi apparatus. They usually contain special enzymes and other chemicals that the cell uses to digest materials in the cell, such as worn out organelles or bacteria that the cell has consumed. They release their contents into the vacuole storing the microbe, and the enzymes do the rest.
Macrophages especially need lysosomes to digest bacteria, viruses, and dead cells, and the production of large amounts of the chemicals stored in the lysosomes can kill the cell. Because of this, macrophages have another organelle, similar to the lysosome, called a peroxisome. The peroxisome is the same as the lysosome, except it is created for the sole purpose of turning the toxic enzymes left over from the lysosomes into oxygen and water.