Glycolysis and Krebs Cycle

Glycolysis and Krebs cycle are two major metabolic pathways in a living cell. The purpose of Glycolysis is to break down glucose into simpler and smaller molecules; whereas, Krebs cycle oxidizes fatty acids and produces more ATP than Glycolysis. For each molecule of glucose, it generates 2 molecules of pyruvate (2ATP) on the aerobic pathway (Glycolysis), whereas a total of 6 molecules of ATP are generated for each molecule of glucose, during Krebs cycle via aerobic (Krebs cycle). 

Knowledge about these differences can help you choose a better pathway for energy production.

For every molecule of glucose, it generates 2 molecules of pyruvate (2ATP) on the aerobic pathway Glycolysis; the remaining 6 molecules of ATP are generated for each molecule of glucose during Krebs cycle via aerobic (Krebs cycle). 

In the process called Metabolism, we break down large molecules into smaller ones. This huge variety of smaller compounds is called metabolites. These metabolites are then used by cells to build new molecules such as proteins and carbohydrates. An important part of this process is what is known as “The Krebs’ Cycle”.

What is Glycolysis?

Glycolysis is the first reaction of the citric acid cycle, which occurs in the inner mitochondrial membrane. The breakdown of glucose produces pyruvate and two molecules of ATP in the presence of oxygen. The rest of the ATP is used by mitochondria for energy production.

Glycolysis is a cycle of metabolic reactions, many of which will occur in the cytoplasm and/or cytosol as glycolytic acid fermentation. When oxygen is present, this cycle can produce two molecules of ATP for each molecule of glucose. Glycolysis in humans, occurring in the cells’ mitochondria, allows aerobic organisms to obtain energy from their food via catabolism (breakdown) by way of substrate-level phosphorylation. Glycolysis is one of three completed chemical shifts in anabolic metabolism, where the other two are oxidation and reduction. “Glycolysis” is a combination of the words glyco (cellulose) and lysis (breakdown or destruction). The high-energy phosphate bonds generated by glycolysis can then be used for energy-requiring processes in cells.

The term “glycolysis” was first used by German biologist Rudolph Auerbach in 1884, who was studying the structure, behaviour and reactions of different enzymes involved in this process.

What is Krebs Cycle?

The Krebs cycle occurs in the outer mitochondrial membrane (cytosol) where it serves as a source of energy for numerous metabolic processes. This process is known to form 3 molecules of ATP, as well as NADH and FADH 2. The remaining two FADH 2 molecules can be used by other metabolic processes like glycolysis. In comparison to the aerobic Krebs cycle, anaerobic Glycolysis produces 2 molecules of pyruvate in the absence of oxygen. On the other hand, the aerobic Krebs cycle produces 12 molecules of ATP in addition to 12 NADH and 4 FADH 2. The total energy produced by Glycolysis is 36 ATP, while energy production via the aerobic Krebs cycle is a total of 38.8 ATP. This proves that the aerobic pathway is a more efficient pathway for the breakdown of glucose.

Glycolysis is a process during which glucose or glycogen is broken down to produce chemical energy that can be used by cells.

Glycolysis and Krebs Cycle: Difference

Conclusion

Glycolysis is a process by which glucose (or glycogen) is broken down to produce chemical energy that can be used by cells. Glycolysis takes place in the cytoplasm. The intermediates obtained by glycolysis are pyruvate, NADH and FADH 2 . In glycolysis, the pyruvic acid produced in glycolysis goes to the mitochondrion, where it enters into the Krebs cycle to be broken down completely into carbon dioxide and water.

This article gives a detailed insight into what is glycolysis, what does this involve and how does it operate within the human body. Krebs cycle is an aerobic process. The final product of glycolysis is pyruvic acid. The process of converting the pyruvic acid into succinic and fumarate differs depending on the enzyme present in the mitochondria and their optimum concentration.

This article is designed to provide a high level description of both glycolysis and the Krebs cycle. To understand what this means for you, we have provided facts, figures, diagrams and explanatory quotations from experts to assist with your understanding.

This article measures the importance of glycolysis within the human body. It provides an explanation as to why it is essential that humans are able to break down glucose into energy using this biochemical process.