What Substances Do Organisms That Use Oxygen Have to Protect

Question

What substances do organisms that use oxygen have to protect themselves from superoxide anions?
A) Hyaluronidase and proteases
B) Exotoxins and superoxide dismutase
C) Enterotoxins and lipase
D) Superoxide dismutase and catalase

Accepted Answer

Organisms that use oxygen have to protect themselves from superoxide anions, which are toxic by-products of cellular respiration. The best way to protect against superoxide anions is by producing enzymes such as superoxide dismutase (which converts superoxide anions into hydrogen peroxide) and catalase (which breaks down hydrogen peroxide into water and oxygen). Therefore, choice D (Superoxide dismutase and catalase) is the best choice.