Do Bacteria Do Glycolysis? 7 Facts You Should Know

Bacteria perform glycolysis to extract energy from glucose. This article will learn about several facts on ‘Do Bacteria Do Glycolysis?’

Bacteria like all other living organisms carry out glycolysis by breaking down glucose. Glycolysis is a glucose metabolic pathway that catabolizes glucose to produce ATP. It is a catabolic process executed in the absence of oxygen.

7 facts you should know about glycolysis:

  1. It is a glucose metabolism process.
  2. Oxygen is not required in this metabolic process.
  3. All living organisms use glycolysis for energy production.
  4. It leads to the production of 2 “energy currency” of the cell, i.e; adenosine triphosphate (ATP).
  5. It uses 10 enzymes for the successful execution of the process.
  6. The cytoplasm is the site for glycolysis.
  7. Pyruvic acid is the end product of glycolysis.

Why do bacteria do glycolysis?

Bacteria do glycolysis for the production of the energy required for cell metabolism.

Bacteria can employ glycolysis or other glucose metabolic pathways depending on their ability to sustain in the presence or absence of oxygen. Facultative and obligate anaerobic bacteria are committed to glycolysis as it does not require oxygen to produce energy.

How do bacteria do glycolysis?

Bacteria do glycolysis by catabolically breaking down glucose in the absence of oxygen.

Which bacteria do glycolysis?

All the bacteria do glycolysis.

Upon glycolysis, obligate aerobic bacteria continue to break the chemical bonds of pyruvic acid by oxidative phosphorylation to produce more ATPs. However, facultative and obligate anaerobic bacteria can produce only 2 ATPs with the help of glycolysis.

Where does glycolysis occur in bacteria?

Glycolysis occurs in the cytoplasm of the bacterial cells.

Following glycolysis, two molecules of pyruvic acid undergo lactate fermentation by getting converted to 2 molecules of lactic acid and generating 2 molecules of NAD+.

Types of glycolysis in bacteria

Embden-Meyerhof-Parnas (EMP) pathway, Entner-Doudoroff (ED) pathway, and Pentose phosphate pathway (PPP) are the three types of glycolysis identified in bacteria.

Embden-Meyerhof-Parnas (EMP) pathway is very popular amongst microbes. Two phases of this metabolic pathway are the investment phase and the payoff phase. In the investment phase, two ATP molecules are invested to split glucose, the six-carbon sugar molecule into two three carbon molecules known as glyceraldehyde – 3 – phosphate. In the payoff phase, glyceraldehyde – 3 – phosphate is oxidized to pyruvate for the production of 4 molecules of ATP and 2 molecules of NADH.

Entner-Doudoroff (ED) pathway is mostly observed in gram-negative bacteria and in specific gram-positive bacteria. Unlike the Embden-Meyerhof-Parnas pathway, the Entner-Doudoroff pathway breaks down one molecule of glucose to produce one molecule of ATP, one molecule of NADM, and one molecule of NADPH. Anaerobic bacteria prefer the EMP pathway over the ED pathway due to the production of 2 molecules of ATP rather than 1.

The pentose phosphate pathway (PPP) metabolizes five-carbon sugar to generate NADPH. It is popularly known as hexose monophosphate shunt as it incorporates pentose sugar in the EMP pathway. Like the EMP pathway, it has 2 phases: oxidative and non-oxidative. In the oxidative phase, glucose-6-phosphate is converted to ribulose-5-phosphate to reduce 2 molecules of NADP+ to NADPH. In the non-oxidative phase, ribulose -5-phosphate is converted to glyceraldehyde-3-phosphate.

What does glycolysis produce in bacteria?

Two molecules of water, 2 molecules of pyruvate, 2 molecules of ATP, and 2 molecules of NADH were produced via bacterial glycolysis.

Pyruvate can be further metabolized through aerobic or anaerobic respiration. Lactic acid is produced in the absence of oxygen by fermenting pyruvate. Pyruvate incorporates itself into the citric acid cycle by entering mitochondria in the presence of oxygen.

Bacterial glycolysis process

Bacterial glycolysis occurs in the cytoplasm of the cell. It is a metabolic pathway for energy generation in almost all organisms.

Glycolysis is an energy source for anaerobic organisms. It catabolizes glucose to generate pyruvic acid which has different fates on the basis of oxygen availability. It is a 10-step process using several enzymes.

do bacteria do glycolysis
Glycolysis from Wikimedia

Step 1

Six carbon glucose is phosphorylated to glucose-6-phosphate (G6P) by hexokinase, thereby preventing the diffusion of glucose- 6-phosphate out of the cell. This step requires an investment of 1 ATP.

Step 2

G6P is rearranged to fructose-6-phosphate (F6P) in a reversible reaction with the help of glucose phosphate isomerase.

Step 3

Phosphofructokinase phosphorylates F6P into fructose 1,6 bisphosphate (F1,6BP) in an irreversible reaction at the expense of ATP hydrolysis.

Step 4

Six carbon F1,6 BP is split into 2 three-carbon molecules viz; glyceraldehyde 3 phosphate and dihydroxyacetone phosphate by aldolase.

Step 5

Triosephosphate isomerase converts dihydroxyacetone into glyceraldehyde 3- phosphate.

Step 6

An oxidoreductase enzyme, glyceraldehyde phosphate dehydrogenase is employed for oxidizing glyceraldehyde 3- phosphate to 1,3- bisphosphoglycerate. Two molecules of NAD+ are reduced in this step to form 2 molecules of NADH.

Step 7

This step generates 2 ATP molecules by transferring a phosphate group from 1,3 BPG to ADP using phosphoglycerate kinase.

Step 8

Phosphoglycerate mutase isomerizes 3-phosphoglycerate to 2- phosphoglycerate.

Step 9

Enolase, a lyase converts 2-phosphoglycerate to phosphoenolpyruvate.

Step 10

In the last step, a molecule of pyruvate is formed by pyruvate kinase, a transferase. Also,  a molecule of ATP is generated.

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