biology

HAAO

HAAO 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 HAAO rather than just read about it. In short: { 3-hydroxyanthranilate 3,4-dioxygenase (EC 1.13.11.6) is an enzyme encoded by the HAAO gene that catalyzes the chemical reaction The two substrates of this enzyme are 3-hydroxyanthranilic acid and oxygen. Its product is 2-amino-3-carboxymuconic semialdehyde.

Key takeaways

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

Reference excerpt

{

3-hydroxyanthranilate 3,4-dioxygenase (EC 1.13.11.6) is an enzyme encoded by the HAAO gene that catalyzes the chemical reaction

The two substrates of this enzyme are 3-hydroxyanthranilic acid and oxygen. Its product is 2-amino-3-carboxymuconic semialdehyde. This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O2 as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O2. The systematic name of this enzyme class is 3-hydroxyanthranilate:oxygen 3,4-oxidoreductase (decyclizing). Other names in common use include 3-hydroxyanthranilate oxygenase, 3-hydroxyanthranilic acid oxygenase, 3-hydroxyanthranilic oxygenase, 3-hydroxyanthranilic acid oxidase and 3HAO. This enzyme participates in tryptophan metabolism. It employs one cofactor, iron.

Structural studies As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes PDB: 1YFU, PDB: 1YFW, PDB: 1YFX, PDB: 1YFY, PDB: 1ZVF, and PDB: 2QNK.h

References

Illustrations

Worked examples

Example 1 — a first encounter with HAAO

Start with the simplest possible case. Write down what HAAO 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 HAAO 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 HAAO 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 HAAO

In research: HAAO 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 HAAO 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: HAAO is common in secondary-school and first-year university syllabi. It links to neighbouring topics EC 1.13.11, Enzymes of known structure, Genes on human chromosome 2, so understanding it makes those chapters shorter.
In everyday life: Look for HAAO 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 HAAO in 20 minutes

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

Frequently asked questions

What is HAAO in simple terms?

{ 3-hydroxyanthranilate 3,4-dioxygenase (EC 1.13.11.6) is an enzyme encoded by the HAAO gene that catalyzes the chemical reaction The two substrates of this enzyme are 3-hydroxyanthranilic acid and oxygen. Its product is 2-amino-3-carboxymuconic semialdehyde.

Why does HAAO 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 HAAO?

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 HAAO.