Question

Draw a flow chart to show various pathways of breaking glucose during respiration. Which pathway produces more energy, and why?

(a) Glycolysis, because it is anaerobic
(b) Krebs cycle, because it produces more CO₂
(c) Electron transport chain, because it involves oxidative phosphorylation
(d) All pathways produce equal energy.

Answer 1

Glycolysis, the Krebs cycle, and the electron transport chain are the pathways involved in breaking glucose during respiration. The electron transport chain produces more energy through oxidative phosphorylation.

Step-by-step explanation:

The pathways involved in breaking glucose during respiration are glycolysis, the Krebs cycle, and the electron transport chain. Glycolysis is the first step and it occurs in the cytosol of cells. It breaks down glucose into two molecules of pyruvate and produces a small amount of ATP.

The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondria. It oxidizes the pyruvate produced by glycolysis into CO₂, and in the process, it generates NADH and FADH₂.

The last step is the electron transport chain, which also occurs in the mitochondria. This step uses the NADH and FADH₂ generated in the Krebs cycle to produce ATP through oxidative phosphorylation.

The pathway that produces the most energy is the electron transport chain. It generates the majority of the ATP through oxidative phosphorylation, which provides a higher yield of ATP compared to glycolysis and the Krebs cycle.