Difference between EMP pathway, ED pathway and HMP pathway
EMP pathway (Embden-Meyerhof-Parnas pathway):
- Also known as glycolysis, it is a metabolic pathway that converts glucose into pyruvate.
- It involves a series of enzymatic reactions that ultimately generate ATP (energy) and pyruvate, which can further undergo fermentation or enter the citric acid cycle.
- The EMP pathway occurs in the cytoplasm of cells and is central to both aerobic and anaerobic respiration.
Read: Osmosis vs Diffusion
ED pathway (Entner-Doudoroff pathway):
- An alternative pathway to glycolysis for the oxidation of glucose to pyruvate.
- It is utilized by some bacteria, archaea, and a few eukaryotes.
- In the ED pathway, glucose is oxidized to pyruvate via a series of enzymatic reactions that generate ATP, NADH, and NADPH.
- This pathway is particularly important in certain microorganisms living in environments with low oxygen levels.
Read: Mitosis vs Meiosis
HMP Pathway:
- HMP pathway (Hexose Monophosphate Pathway), also known as the Pentose Phosphate Pathway (PPP):
- It is a metabolic pathway parallel to glycolysis that occurs in the cytoplasm of cells.
- The primary function of the HMP pathway is to generate NADPH, which is essential for biosynthetic reactions and antioxidant defense mechanisms.
- Additionally, the pathway produces ribose-5-phosphate, a precursor for the synthesis of nucleotides and other important cellular molecules.
- The HMP pathway is especially active in tissues with high biosynthetic demands, such as the liver, adipose tissue, and rapidly dividing cells.
Read: Glycolysis vs TCA cycle
Difference between EMP pathway, ED pathway and HMP pathway:
Feature | EMP Pathway | ED Pathway | HMP Pathway |
---|---|---|---|
ATP Generation per Glucose Molecule | Generates 2 molecules of ATP | Generates 1 molecule of ATP per glucose molecule | Does not generate ATP |
End Products | Pyruvate or lactic acid | Pyruvate or PGLAD | Fructose 6 phosphate and PGLAD |
Intermediates | Consists of 3 and 6 carbon sugars | Contains only 6 carbon sugars | Consists of 3, 4, 5, and 6 carbon sugars |
Anaerobic/Aerobic Nature | Anaerobic breakdown of sugars | Oxidative breakdown of sugars and sugar acids | Not specified |
Phases | Preparative phase and payoff phase | Not divided into any phases | Oxidative irreversible and non-oxidative reversible phase |
Reducing Power Molecules | Does not generate any | Generates NADPH+ and H+ | Generates 2 molecules of NADPH+ and H+ |
Substrate Utilization | Utilizes glucose as a substrate | Can utilize glucose, gluconic acid, sugar acids | Begins with glucose-6-phosphate |
Pathway Universality | Followed by plants, animals, and microbes | Specialized pathway for certain bacteria | Followed in specific eukaryotic tissues |
Difference between EMP pathway, ED pathway and HMP pathway in Points:
Differences between the EMP (Embden-Meyerhof-Parnas) Pathway, the ED (Entner-Doudoroff) Pathway, and the HMP (Hexose Monophosphate) Pathway:
1. ATP Generation per Glucose Molecule:
- EMP Pathway: Generates 2 molecules of ATP per glucose molecule.
- ED Pathway: Generates 1 molecule of ATP per glucose molecule.
- HMP Pathway: Does not generate ATP.
2. End Products:
- EMP Pathway: Produces pyruvate or lactic acid.
- ED Pathway: Produces pyruvate or phosphoglyceraldehyde (PGLAD).
- HMP Pathway: Produces fructose 6-phosphate and PGLAD.
3. Intermediates:
- EMP Pathway: Consists of 3 and 6 carbon sugars.
- ED Pathway: Contains only 6-carbon sugars.
- HMP Pathway: Consists of 3, 4, 5, and 6 carbon sugars.
4. Aerobic/Anaerobic Nature:
- EMP Pathway: Follows anaerobic breakdown of sugars.
- ED Pathway: Oxidative breakdown of sugars and sugar acids.
- HMP Pathway: Not specified, but it is likely to be aerobic.
5. Phases:
- EMP Pathway: Divided into preparatory phase and payoff phase.
- ED Pathway: Not divided into any phases.
- HMP Pathway: Divided into oxidative irreversible and non-oxidative reversible phase.
6. Reducing Power Molecules:
- EMP Pathway: Does not generate any reducing power molecule.
- ED Pathway: Generates NADPH+ and H+.
- HMP Pathway: Generates 2 molecules of NADPH+ and H+.
7. Substrate Utilization:
- EMP Pathway: Begins with the utilization of glucose as a substrate.
- ED Pathway: Can utilize glucose, gluconic acid, mannonic acid (sugar acids).
- HMP Pathway: Begins with the utilization of glucose-6-phosphate.
8. Pathway Universality:
- EMP Pathway: Universal pathway followed by plants, animals, and microbes.
- ED Pathway: Specialized pathway followed by certain bacteria like Pseudomonas, Xanthomonas, and Azotobacter.
- HMP Pathway: Followed in eukaryotic adipose tissue, adrenal cortex, and mammary glands.
Read:
- 5 Difference between red muscle and white muscle fibers
- 5 Important difference between Tendon and Ligaments
- Difference Between Prokaryotic and Eukaryotic Cell
- Difference Between Glycolysis and Gluconeogenesis
- Difference Between Pectoral and Pelvic Girdle
- Difference Between Active and Passive Transport
- Difference between Glycolysis and TCA Cycle