What Did I Learn?

1. The following questions will help you review concepts presented in this module.
   Consider the following reaction:

   Monoamine oxidase

   Dopamine + Oxygen —————-> DPA + H₂O₂ + NH₃

   H₂O

   In this example, which of the following is oxidized and which is reduced?

   1. Dopamine is oxidized, hydrogen peroxide is reduced
   2. Dopamine is reduced, oxygen is oxidized
   3. Dopamine is oxidized, oxygen is reduced
   4. Dopamine is reduced, hydrogen peroxide is oxidized
2. In this module, you learned that the neurotransmitter dopamine is oxidized by molecular oxygen (O₂) with the help of an enzyme called monoamine oxidase. This means that the oxygen:
   1. Donates a proton to dopamine
   2. Accepts a proton from dopamine
   3. Donates an electron to dopamine
   4. Accepts an electron from dopamine
3. Methamphetamine, a central nervous system stimulant, causes increased alertness and agitation by causing:
   1. Oxidation of dopamine
   2. Rapid onset Parkinson’s disease
   3. Release of dopamine
   4. Formation of free radicals
4. When a drug user takes methamphetamine, it releases the neurotransmitter dopamine into the synaptic space. There, the dopamine is autooxidized by O₂, without the help of enzymes. In this case the autooxidation of dopamine results in the production of an unstable molecule called:
   1. Hydrogen peroxide (H₂O₂)
   2. Superoxide radical (O₂*-)
   3. Ammonia (NH₃)
   4. Oxygen
5. In this module you learned about some of the dangers of free radicals in the body. Free radicals oxidize lipids, proteins, and DNA, disorganizating their structure. Which of the following is a consequence of the oxidation of lipids in a cell membrane?
   1. Water leaves the cells and causes them to shrink
   2. The carbon chains in the lipids can get kinky causing the cell to become leaky
   3. Disulfide bonds are formed
6. As you have learned, oxygen radicals can produce a range of detrimental effects. One way in which our bodies reduce the damage caused by oxygen radicals is to:
   1. Increase release of dopamine
   2. Increase exposure to UV radiation
   3. Activate enzymes that scavenge oxygen radicals

Now, check your answers here.