Discussion
Another sugar, mannose, was added to mouse cells, and mannose crystals formed inside lysosomes. Similar to sucrose crystals, the mannose crystals disappeared in a few days after the sugar was removed from the medium. If invertase were added to the culture immediately after mannose was removed, what would you predict would happen?
*This question is included in 10. Cellular Organelles, question #4
| (A) | The mannose crystals would disappear in less than two days. |
| (B) | ... |
| (C) | ... |
| (D) | ... |
| (E) | ... |
| (F) | ... |
The solution is
Posted: 04/12/2013 11:11
But mannose is a monosaccharide in its monomeric form, sharing close resemblance to glucose. It should not take as long as sucrose to be metabolized by the cell, which is a disaccharide of glucose and fructose. Unless mannose has to be converted to glucose before cell use, should it not require less time to metabolize? I'm Assuming equal amounts based on the number of molecules in the polymer, rather than physically equal mass quantities.
Posted: 04/17/2013 13:19
The Option B is correct because we are talking about the specificity of enzymes in a particular degradation reaction of biological molecules. Invertase cannot catalyze the degradation of mannose into monosachharide. Yes, mannose has to be converted to glucose before cell use. Here, we need to consider the optical activity and inversion of configuration while deciphering enzyme specificity for the reaction.