biology

Granadaene

Granadaene is a biology 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 Granadaene rather than just read about it. In short: Granadaene is the trivial name of a polyene of non-isoprenoid biosynthetic origin, that constitutes the red pigment characteristic of Streptococcus agalactiae (group B streptococcus). Characteristics Granadaene contains a conjugated system made up of a linear chain of 12 conjugated carbon-carbon double bonds which is connected to the amino acid ornithine at one end and the sugar rhamnose at the other.

Key takeaways

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

Reference excerpt

Granadaene is the trivial name of a polyene of non-isoprenoid biosynthetic origin, that constitutes the red pigment characteristic of Streptococcus agalactiae (group B streptococcus).

Characteristics Granadaene contains a conjugated system made up of a linear chain of 12 conjugated carbon-carbon double bonds which is connected to the amino acid ornithine at one end and the sugar rhamnose at the other. Granadaene contains 12 conjugated double bonds, a feature which is unprecedented among non-isoprenoid pigments. Granadaene is dark red, odorless, insoluble in water, methanol, ethanol, diethyl ether, acetone, hexane, dimethyl sulfoxide (DMSO), acetonitrile, tetrahydrofuran, chloroform, and in most solvents, it is soluble in DMSO–0.1% trifluoroacetic acid (TFA). Granadaene, can be extracted from cultures of S.agalactiae in granada broth (granada medium without agar) with 0.1 M potassium hydroxide (KOH) and purified by size-exclusion chromatography on Sephadex LH using DMSO–0.1%TFA.

The fine-structure of the ultraviolet-visible absorption spectrum of the granadaene (in DMSO/TFA) is almost identical to that of a carotene with a similar conjugated system of 12 double bonds (e.g. alpha-carotene), which is why the GBS pigment was considered to be a carotene for many years. Polyenes up to 10 conjugated double bonds are also a bizarre class of biologically natural products (laetiporic acids) found in the basidiomycete Laetiporus sulphureus.

Granadaene and S.agalactiae detection and identification Production of the red pigment granadaene is a phenotypic trait specific to β-hemolytic GBS, and because of that, detection of red colonies from clinical samples, when cultivated on granada medium, allows the straightforward identification of GBS.

Biological relevance Granadaene is an organic compound produced by S.agalactiae. It is the product of a metabolic pathway similar to that of biosynthesis of fatty acids. The enzymes necessary for the biosynthesis of granadaene in GBS are coded by a gene cluster of 12 genes, the cyl operon, Among the cyl operon, the cylE gene is required for pigment production, and transcription of cyl genes is regulated by the CovR/S two-component system, and a pathway for the pigment biosynthesis requiring all the genes of the cyl operon has been proposed. Like the biosynthesis of the pigment, the hemolytic activity also requires in GBS the 12 genes of the cyl operon. Moreover, it has been proposed that granadaene is indeed the hemolysin of S.agalactiae The pigment is localized, in GBS, in the cell membrane, where it could play a role in membrane stabilization, similar to the role of carotenes in other bacterial membranes. In addition to S.agalactiae the presence of granadaene and the cyl genes has been reported in pigmented Acidipropionibacterium spp. (former Propionibacterium) as A.jensenii, A.thoenii, and A.virtanenii, where it can cause defects such as red spots in some cheeses. Probably granadaene is also present in other related species such as Pseudopropionibacterium rubrum. Granadaene is also produced by strains of Lactocococcus garvieae/petaury/formosensis group where the cyl cluster is also present. The cyl genes have been cloned in Lactococcus lactis (a non-hemolytic non-pigmented Gram-positive bacterium) and the expression of the GBS cyl operon conferred hemolysis, pigmentation, and cytotoxicity to Lactococcus lactis. Proving that the expression of the genes of the cyl operon is sufficient for Granadaene production in a heterologous host.

Granadaene and GBS Virulence The hemolytic activity of granadaene is strongly linked to the length of its polyene chain. It has been proposed that granadaene is indeed the hemolysin of S.agalactiae, the GBS hemolysin is a broad-spectrum cytolysin able to destroy many eukaryotic cells, including platelets. Because of this, granadaene is considered an important virulence factor for GBS. Nevertheless, 1–5% of GBS strains are non-hemolytic and do not produce pigment. These non-hemolytic and non-pigmented GBS strains (lacking pigment and hemolysin) are considered less virulent because of that.

References

Illustrations

Granadaene: Ultraviolet/visible spectrum of granadaene, in DMSO+TFA — Ultraviolet/visible spectrum of granadaene, in DMSO+TFA

Worked examples

Example 1 — a first encounter with Granadaene

Start with the simplest possible case. Write down what Granadaene claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Granadaene 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 Granadaene 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 Granadaene

In research: Granadaene appears in biology 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 Granadaene 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: Granadaene is common in secondary-school and first-year university syllabi. It links to neighbouring topics Biological pigments, Polyenes, Rhamnosides, so understanding it makes those chapters shorter.
In everyday life: Look for Granadaene 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.

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How to study Granadaene in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Granadaene 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 Granadaene out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Granadaene in simple terms?

Granadaene is the trivial name of a polyene of non-isoprenoid biosynthetic origin, that constitutes the red pigment characteristic of Streptococcus agalactiae (group B streptococcus). Characteristics Granadaene contains a conjugated system made up of a linear chain of 12 conjugated carbon-carbon do…

Why does Granadaene matter?

Because it connects several biology 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 Granadaene?

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 Granadaene.