Peroxisome, ribosome and lysosome all are present in animal cells. Peroxisomes (uricosome) are single membrane bound, sac-like cytoplasmic organelles. They contain peroxide producing enzyme (oxidases) and peroxide destroying enzymes (catalases). Lysosomes are single membrane bound, reservoirs of hydrolytic enzymes used for the intracellular digestion of macro-mokcuhes. All the enzymes are acid hydrolases (optimally active at pH 5.0). Ribosomes are amembranous ribonucleoprotein particles. 70S type of ribosomes are found in prokaryotes, mitochondria and chloroplast where as 80S type in eukaryotic cytoplasm. These are the site of protein synthesis.