How Many ATP Molecules are Generated During Glycolysis

Introduction

Organisms do many jobs which require energy even if organisms are resting like a rock, they require energy. The smallest and largest organisms require energy for survival but in different amounts. When you are kicking a ball, you use more energy than when you are sleeping. Here we will look over one step from the many steps of energy production.

Energy Production

Respiration is a process through which we produce energy. It consists of two steps;

1. Breathing

2. Cellular respiration

Breathing is inhaling and exhaling the air, for example, humans inhale air rich in oxygen and exhale carbon dioxide.

Cellular Respiration: Process in which fuel(food) is oxidised in the presence of oxygen.

Respiration can be classified as anaerobic and aerobic.

Respiration, in which the breakdown of food occurs in the presence of oxygen, is aerobic respiration. Humans, dogs, and plants are the organisms that perform cellular respiration in the presence of oxygen.

Respiration, in which the breakdown of food takes place in the absence of oxygen, is aerobic respiration. Yeast, bacteria, etc., are the organisms that perform cellular respiration in the presence of oxygen.

Common Step in All Types of Respiration

We have already discussed two types of respiration; anaerobic and aerobic respiration.

Steps in anaerobic respiration

Glycolysis

Steps in aerobic respiration

Glycolysis

Krebs Cycle

Terminal Oxidation

We can see from the above that both types of respiration have one common step: glycolysis.

Glycolysis:

Glycolysis is a process in which the partial breakdown of glucose occurs. It is also known as the EMP pathway, as it was discovered in 1930 by three scientists from Germany. The names of three scientists are Embden, Otto Meyerhof and J. Parnas.

It involves the partial oxidation of hexose sugar or glucose into 2 molecules of pyruvic acid. It involves a chain of ten enzyme-mediated processes. It takes place in the cytoplasm or cytosol.

Ten Steps of Glycolysis

• Fructose or glucose, a respiratory substrate, is formed by the hydrolysis of sucrose or starch.

• By ATP, phosphorylation of glucose-6-phosphate from glucose occurs in the presence of hexokinase enzyme and Mg2+.

• Fructose-6- phosphate formation takes place from the Glucose-6- phosphate in the presence of phosphohexose enzymes. Fructose-6- phosphate is the isomer of Glucose-6- phosphate.

• By ATP, further phosphorylation of Fructose-6-phosphate occurs in the presence of phosphofructokinase enzyme and Mg2+, which results in the formation of fructose 1, 6 biphosphates.

• Splitting of fructose 1, 6 bisphosphate occurs to form one molecule each of dihydroxyacetone acetone 3-phosphate; and 3- carbon compound, glyceraldehyde 3-phosphate(PGAL) further is tautomerism to glyceraldehyde 3-phosphate.

• Glyceraldehyde phosphate dehydrogenase occurs in the presence of an enzyme. It forms NADH by losing hydrogen to NAD and taking inorganic phosphate from the H3PO4, which results in forming 1, 3-biphosphoglycerate.

• 1 of the 2 phosphates of biphosphoglycerate is attached by the high-energy bond to form 3-phosphoglycerate and ATP.

• 2-phosphoglycerate forms from the 3-phosphoglycerate in the presence of the phosphoglyceromutase enzyme.

• 2-phosphoglycerate converted into phosphoenol pyruvate(PEP).

• During phosphoenol and pyruvate formation radicle of phosphate picks up energy which results in the formation of ATP molecules, and the pyruvate kinase enzyme catalyses the transformation of PEP into pyruvate.

End Products of Glycolysis

ATP: Energy Molecules

ATP is the currency molecule, it stands for Adenosine triphosphate (ATP). ATP traps the chemical energy obtained from the breakdown of food. It is a nucleotide molecule.

It is composed of three phosphate molecules and adenosine. ATP is soluble in water

The main component of ATP are;

1. Nitrogen base

2. Pentose sugar molecule(ribose)

3. 3 phosphate groups

Three phosphate groups of ATP are known as high-energy bonds; broken, they release a huge amount of energy. In the glycolysis process, 4 ATP are produced.