Glycolysis is the process by which glucose is broken down to pyruvate through a series of enzymatic reactions, producing a small amount of ATP. It occurs in the cytoplasm of cells and is the first step in both aerobic and anaerobic respiration. There are three phases - the energy investment phase requires energy to phosphorylate glucose, the splitting phase breaks the six-carbon glucose into two three-carbon molecules, and the energy payoff phase generates ATP through substrate-level phosphorylation. Glycolysis is regulated by enzymes and produces pyruvate or lactate depending on whether it occurs with or without oxygen.

1. GLYCOLYSIS
METABOLISM OF CARBOHAYDRATE
BY- HIMANSHU PANERU
BMLT

2. # INTRODUCTION
■ Glycolysis is defined a the sequence of rxn. Converting glucose to
pyruvate or lactose with the production of ATP.
or
■ Glycolysis is the process of Breaking Down glucose and forming
pyruvate with the production of two molecules of ATP it is called
glycolysis.
or
■ Glycolysis is the first step in the breakdown of glucose to extract
energy for cellular metabolism.

3. # IMPORTANT POINTS
■ glycolysis takes part in all cell of the body.
■ if glycolysis occur in the absence of oxygen called Anaerobic or in the
presence of oxygen called Aerobic.
■ Lactate is the end product under anaerobic condition.
■ pyruvate is the end product under aerobic condition which is oxidised
to form carbon dioxide and water.
■ glycolysis provide energy to mature RBC.

4. # IMPORTANT POINTS
■ During sternous exercise energy provided by glycolysis.
■ There is no activity of glycolysis in cardiac muscle.
■ it is responsible for generation of non- essential amino acid and
glycerol part of the fat.

5. # GLYCOLYSIS RXN.
■ it is done on the basis of three steps :
(i) Energy investment phase or primary stage.
(ii) Splinting phase
(iii) Energy regulation phase

6. GLYCOLYSIS CYCLE

7. Energy investment phase
Step 1 : In glucose Hexokinase or Glucokinase enzyme is add by which
glucose 6 phosphate formed.
Step 2 : Then glucose 6 phosphate convert into Fructose 6 phosphate in
the presence of isomerase.
Step 3 : Fructose 6 phosphate is phosphorylated to Fructose 1,6-
bisphosphate by phosphofructokinase (PFK) this step is Irreversible in
glycolysis.

8. Splitting phase
Step 4 : Fructose 1,6 Bisphosphate is split to two three carbon
compound, glyceraldehyde 3- phosphate and dihydroxyacetone
phosphate by the enzyme aldolase.
Step 5 : The enzyme phosphotriose isomerase catalys the reversible
interconversion of glyceraldehyde 3-phosphate. Thus two molecule of
glyceraldehyde 3-phosphate are obtain from one molecule of glucose

9. Energy generation phase
Step 6 : Glyceraldehyde 3-phosphate phosphate dehydrogenase convert
glyceraldehyde 3-phosphate phosphate to 1,3-bisphosphoglycerate.
This step is important as it involved in the formation of NADH+H and
a high energy compound 1,3-bisphosphoglycerate.
Step 7: The enzyme phosphoglycerate kinase act on 1,3-
bisphosphoglycerate resulting in the synthesis of ATP and formation of 3-
phosphoglycerate.
This step is good example of substrate level phosphorylation. since
ATP synthesis from substrate without the involvement of electron
transport chain (ETC).

10. Step 8 : 3-phosphoglycerate is convert to 2-phosphoglycerate by
phosphoglycerate mutase. This is an isomerization reaction
Step 9 : this high energy compound Phosphoenolpyruvate is generated
from 2-phosphoglycerate by the enolase.
The enzyme pyruvate kinase catalyses the transfer of high-energy
phosphate from phosphoenolpyruvate to ADP, leading to the formation of
ATP.
This step also a substrate level phosphorylation.
This step also Irreversible.

11. # SUBSTRATE LEVEL
PHOSPHORYLATION
■ glycolysis process there is too important substrate level
phosphorylation reaction occur :
(I) Bisphosphoglycerate kinase
(II) Pyruvate kinase

12. # IRREVERSIBLE RXN.
(I) Hexokinase/Glucokinase
(II) phosphofructokinase (PFK)
(III) Pyruvate kinas

13. # REGULATIONS OF GLYCOLYSIS
ENZYME ACTIVATION INACTIVATION
Hexokinase/Glucokinase Insuline Glucagon, glucose 6-phosphate
PFK Insulin, fructose 2,6-BP glucagon
Pyruvate kinase Insulin, fructose 1,6-BP glucagon

14. # NOTE
■ In aerobic condition pathway generate 7 ATP molecules.
■ In anaerobic condition pathway generate 2 ATP molecules

15. thanku you