Question

Given the inefficiency of two of the pathways shown in figure 9-4, what advantage could there be to using these pathways to produce energy?

Answer 1

Answer:

Pathway A and B are anaerobic ways of extracting energy (ATP) from glucose. These pathways are advantageous when little or no oxygen present. The net energy in both pathways is 2ATP. Both pathywas take place in the cytosol of the cell and are categorized as fermentation.

Pathway C is aerobic in which oxygen is used to yield energy (ATP). This pathway is advantageous when energy needs are high because it produces 36 molecules of ATP. Therefore, net energy in this pathway is higher than the anaerobic pathways. This pathyway takes place within the mitochondria and is recognized as cellular respiration.

A schematic illustration can be seen in the image attached.

PS: Glycolysis is common to fermentation and aerobic respiration.