A question was posed in our Carbohydrates Chemistry class regarding glucose. Every biochemistry student surely knows that glucose is the ubiquitous energy source of catabolic pathways. The question is, why?
Apparently, one of the proposed reasons is that it is present before life existed, hence, it is already waiting and available when the first living organism first appeared. Details are in this 2008 journal:
Other notes and
homeworks concerns in our class will be published to my other site so as not to crowd this one too much