While performing undergraduate research on the facultative aerobe Saccharomyces cerevisiae (yeast) you discover a mutant able to directly convert glyceraldehydes 3-phosphate into 3-phosphoglycerate, bypassing the formation of 1,3-bisphosphoglycerate and the need to make the enzyme glyceraldehydes 3-phosphate dehydrogenase altogether, shortening the glycolytic pathway by one whole step (much to the delight, you imagine, of future cell biology students!). However, to your surprise, you discover that your facultative aerobe is now an obligate aerobe. Explain in terms of the glycolytic steps involved why this is so.