Questions from Students concerning the Exam

Joseph Dixon ♦ February 16, 2015 ♦ Leave a comment

I’ve had quite a few questions over the past few days.  I will answer those questions in this post.

1.  What numbers do I need to know for the exam?

Answer:   I do not mind answering this question although I think I have mentioned the important ones several times in class.  You have to know the Atwater numbers for carbohydrates, fat, and protein.  Another number that would be good to know is the approximate amount of glucose that can be stored as glycogen in the muscle and liver.  It would be a good idea to know what is the breakdown of energy in the diet contributed by the macronutrients in the average American diet.  You also have to know some other percents–but in most cases I think you will be able to figure these out.  You do not need to know numbers for the glycemic index of particular foods.  You do have to know what a high glycemic index tells us about a food or a process.

2. The following question was asked by several students–How did finding out the mechanism of glucose uptake into the enterocyte, which involves co-transport of glucose and sodium into the cell and that sodium was absolutely required for uptake of glucose, save the lives a millions of children from severe diarrhea?

Answer:  Good question.  This was told to me by a physician (who is quite old now) who used to travel in developing countries to treat children.  He said that early on when children had severe diarrhea they had very little to help the child and many children died because of the dehydration and lack of energy caused by the diarrhea.  Then when the discovery was made concerning the glucose transporter, some pediatrician tried putting sodium into water with glucose and gave it to a child and it worked! And the news traveled like wild fire among third world physicians.  Before this, he said, it was unthinkable to put sodium into something the child drank.  After all, who would give sodium to someone dying of thirst in the dessert?  Because of this discovery, Ross laboratories developed Pediacare, which is a commercial product that contains salt and glucose and other electrolytes.  Also, Gator aid was established for athletes, and this really took off too-especially due to promotion through commercials by Michael Jordan and other sports stars.

So now it is accepted that sodium helps with rapid transport of glucose and water into the enterocyte, but at one time, this was not known.  This is an example where bench biochemistry influenced the health and welfare of many people!