CBSE Class 11-science Answered

• Glycolysis is also called the EMP pathway because the steps of this biochemical pathway were worked out by the German scientists Gustav Embden, Otto Meyerhof and Jakub Parnas in 1930s
• Glycolysis is the common pathway seen in both aerobic and anaerobic respiration.
• In plants, glucose is derived from sucrose.
• Sucrose is converted into glucose and fructose in the presence of the enzyme invertase

Steps in Glycolysis

• Glucose (6C) is phosphorylated to glucose-6-phosphate (6C) in the presence of the enzyme hexokinase. One molecule of ATP is consumed during this step.
• Glucose-6-phosphate (6C) isomerises into fructose-6-phosphate (6C) in the presence of the enzyme phosphohexoisomerase.
• Fructose-6-phosphate (6C) is phosphorylated to fructose-1, 6-biphosphate (6C) in the presence of the enzyme phosphofructokinase (PFK). One molecule of ATP is used during this step.
• Fructose-1, 6-biphosphate (6C) splits into two 3C molecules—glyceraldehydes-3-phosphate (PGAL) (3C) and dihydroxyacetone phosphate (DHAP) (3C)—in the presence of the
  enzyme aldolase.
• Dihydroxyacetone phosphate (DHAP) (3C) is isomerised to glyceraldehyde-3-phosphate (PGAL) (3C) in the presence of the enzyme phosphotriose isomerase. 
• Glyceraldehyde-3-phosphate is phosphorylated to form 1, 3-bisphosphoglyceric acid (3C).
• 1, 3-Bisphosphoglyceric acid (3C) transfers its one phosphate group to ADP and gets converted to 3-phosphoglyceric acid (3C). This results in the formation of ATP.
• 3-Phosphoglyceric acid (3C) is converted to 2-phosphoglycerate (3C) in the presence of the enzyme phosphoglyceromutase.
• 2-Phosphoglycerate loses its water molecule and forms phosphoenolpyruvate in the presence of the enzyme enolase.
• The high-energy phosphate group of phosphoenol pyruvate (3C) is transferred to ADP in the presence of the enzyme pyruvate kinase to form pyruvate (3C). This results in the formation of ATP.