science

Sulfoglycolysis

Sulfoglycolysis is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sulfoglycolysis rather than just read about it. In short: Sulfoglycolysis is a catabolic process in primary metabolism in which sulfoquinovose (6-deoxy-6-sulfonato-glucose) is metabolized to produce energy and carbon-building blocks. Sulfoglycolysis pathways occur in a wide variety of organisms, and enable key steps in the degradation of sulfoquinovosyl diacylglycerol (SQDG), a sulfolipid found in plants and cyanobacteria into sulfite and sulfate.

Key takeaways

Sulfoglycolysis belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sulfoglycolysis to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sulfoglycolysis from memory before moving on to harder problems.

Reference excerpt

Sulfoglycolysis is a catabolic process in primary metabolism in which sulfoquinovose (6-deoxy-6-sulfonato-glucose) is metabolized to produce energy and carbon-building blocks. Sulfoglycolysis pathways occur in a wide variety of organisms, and enable key steps in the degradation of sulfoquinovosyl diacylglycerol (SQDG), a sulfolipid found in plants and cyanobacteria into sulfite and sulfate. Sulfoglycolysis converts sulfoquinovose (C6H12O8S−) into various smaller metabolizable carbon fragments such as pyruvate and dihydroxyacetone phosphate that enter central metabolism. The free energy is used to form the high-energy molecules ATP (adenosine triphosphate) and NADH (reduced nicotinamide adenine dinucleotide). Unlike glycolysis, which allows metabolism of all carbons in glucose, sulfoglycolysis pathways convert only a fraction of the carbon content of sulfoquinovose into smaller metabolizable fragments; the remainder is excreted as C3-sulfonates 2,3-dihydroxypropanesulfonate (DHPS) or sulfolactate (SL); or C2-sulfonates isethionate or sulfoacetate. Several sulfoglycolytic pathways are known:

The sulfoglycolytic Embden-Meyerhof-Parnas (sulfo-EMP) pathway, first identified in Escherichia coli, involves the degradation of sulfoquinovose to 2,3-dihydroxypropanesulfonate (DHPS), and shares similarity with the Embden-Meyerhof-Parnas glycolysis pathway. This pathway leads to the production of the C3 intermediate dihydroxyacetone phosphate. The sulfoglycolytic Entner-Doudoroff (sulfo-ED) pathway, first identified in Pseudomonas putida SQ1, involves the degradation of sulfoquinovose to sulfolactate, and shares similarity to the Entner-Doudoroff pathway of glycolysis. This pathway leads to the production of the C3 intermediate pyruvate. The sulfofructose transaldolase pathway, first identified in Bacillus aryabhattai and Bacillus megaterium, involves isomerization of SQ to sulfofructose, and then a transaldolase cleaves SF to 3-sulfolactaldehyde (SLA), while the non-sulfonated C3-(glycerone)-moiety is transferred to an acceptor molecule, glyceraldehyde phosphate (GAP), yielding fructose-6-phosphate (F6P). The SLA released can either be oxidized (to sulfolactate) or reduced (to dihydroxypropanesulfonate) and then excreted. The sulfoglycolytic transketolase (sulfo-TL) pathway was first identified in Clostridium sp. MSTE9. It involves isomerization of SQ to sulfofructose, and then a transketolase cleaves SF to 4-sulfoerythrose (SE), while the C2-moiety is transferred to an acceptor molecule, glyceraldehyde phosphate (GAP), yielding xylulose-5-phosphate (Xu5P). 4-Sulfoerythrose is isomerized to 4-sulfoerythrulose (SEu), whereupon a second round of transketolase catalyzed reaction cleaves SE to sulfoacetaldehyde, while the non-sulfonated C2-moiety is transferred to an acceptor molecule, glyceraldehyde phosphate (GAP), yielding a second molecule of xylulose-5-phosphate (Xu5P). Finally, the sulfoacetaldehyde is reduced to isethionate and excreted. Additionally, there are sulfoquinovose 'sulfolytic' pathways that allow degradation of sulfoquinovose through cleavage of the C-S bond. These include:

The sulfoglycolytic sulfoquinovose monooxygenase (sulfo-SMO) pathway, first identified in Agrobacterium tumerfaciens and Novosphingobium aromaticivorans, involves the degradation of sulfoquinovose to glucose and sulfite. Glucose formed in this pathway enters glycolysis. The sulfoglycolytic sulfoquinovose dioxygenase (sulfo-SMO) pathway. In all pathways, energy is formed by breakdown of the carbon-rich fragments in later stages through the 'pay-off' phase of glycolysis through substrate-level phosphorylation to produce ATP and NADH.

Growth of bacteria on sulfoquinovose and its glycosides A range of bacteria can grow on sulfoquinovose or its glycosides as sole carbon source. E. coli can grow on sulfoquinovose, methyl α-sulfoquinovoside and α-sulfoquinovosyl glycerol. Growth on sulfoquinovosyl glycerol is both faster and leads to higher cell density than for growth on sulfoquinovose. Pseudomonas aeruginosa strain SQ1, Klebsiella sp. strain ABR11, Klebsiella oxytoca TauN1, Agrobacterium sp. strain ABR2, and Bacillus aryabhattai can grow on sulfoquinovose as sole carbon source. A strain of Flavobacterium was identified that could grow on methyl α-sulfoquinovoside.

Production of sulfoquinovose and its mutarotation

Sulfoquinovose is rarely found in its free form in nature; rather it occurs predominantly as a glycoside, SQDG. SQDG can be deacylated to form lyso-SQDG and sulfoquinovosylglycerol (SQGro). Sulfoquinovose is obtained from SQ glycosides by the action of sulfoquinovosidases, which are glycoside hydrolases that can hydrolyse the glycosidic linkage in SQDG, or its deacylated form, sulfoquinovosyl glycerol (SQGro). There are two main classes of sulfoquinovosidases. The first are classical glycoside hydrolases (which belong to CAZy family GH31), and is exemplified by the sulfoquinovosidase YihQ from Escherichia coli. Family GH31 sulfoquinovosidases cleave SQ glycosides with retention of configuration, initially forming α-sulfoquinovose. YihQ sulfoquinovosidase exhibits a preference for the naturally occurring 2'R-SQGro. The second class of sulfoquinovosidases are NAD+-dependent enzymes (which belong to CAZy family GH188) that use an oxidoreductive mechanism to cleave both α- and β-glycosides of sulfoquinovose. Sulfoglycolysis encoding operons often contain gene sequences encoding aldose-1-epimerases that act as sulfoquinovose mutarotases, catalyzing the interconversion of the α and β anomers of sulfoquinovose.

Sulfo-EMP pathway

The major steps in the sulfo-EMP pathway are:

… excerpt ends here. Continue reading the full article.

Illustrations

Sulfoglycolysis: The sulfoglycolytic Embden-Meyerhof-Parnas pathway. — The sulfoglycolytic Embden-Meyerhof-Parnas pathway.

Sulfoglycolysis: The sulfoglycolytic Entner-Douderoff pathway. — The sulfoglycolytic Entner-Douderoff pathway.

Worked examples

Example 1 — a first encounter with Sulfoglycolysis

Start with the simplest possible case. Write down what Sulfoglycolysis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sulfoglycolysis before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sulfoglycolysis ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sulfoglycolysis

In research: Sulfoglycolysis appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sulfoglycolysis in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sulfoglycolysis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Metabolism, so understanding it makes those chapters shorter.
In everyday life: Look for Sulfoglycolysis outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Sulfoglycolysis” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Sulfoglycolysis in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sulfoglycolysis means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sulfoglycolysis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sulfoglycolysis in simple terms?

Why does Sulfoglycolysis matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sulfoglycolysis?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sulfoglycolysis.