biology

L-threonine 3-dehydrogenase

L-threonine 3-dehydrogenase 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 L-threonine 3-dehydrogenase rather than just read about it. In short: In enzymology, L-threonine 3-dehydrogenase (EC 1.1.1.103), or just threonine dehydrogenase, is an enzyme that participates in the process of breaking down threonine in certain non-human organisms like mice. In particular, it catalyzes the chemical reaction The two substrates of this enzyme are L-threonine and oxidised nicotinamide adenine dinucleotide (NAD+).

Key takeaways

L-threonine 3-dehydrogenase belongs to biology; place it in that map before memorising details.
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Reference excerpt

In enzymology, L-threonine 3-dehydrogenase (EC 1.1.1.103), or just threonine dehydrogenase, is an enzyme that participates in the process of breaking down threonine in certain non-human organisms like mice. In particular, it catalyzes the chemical reaction

The two substrates of this enzyme are L-threonine and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are (S)-2-amino-3-ketobutyric acid, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-threonine:NAD+ oxidoreductase. Other names in common use include L-threonine dehydrogenase, and threonine 3-dehydrogenase.

In humans

In humans, the homolog gene, TDH, is a non-functional pseudogene. The loss of an acceptor splice site consistently leads to a non-functional truncated protein. The primary pathway for threonine degradation in humans instead starts with threonine ammonia-lyase (aka threonine dehydratase) and produces propionyl-CoA instead of glycine.

Structural studies As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes PDB: 2D8A, PDB: 2DFV, and PDB: 2DQ4.

References

Illustrations

Worked examples

Example 1 — a first encounter with L-threonine 3-dehydrogenase

Start with the simplest possible case. Write down what L-threonine 3-dehydrogenase 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 L-threonine 3-dehydrogenase 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 L-threonine 3-dehydrogenase 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 L-threonine 3-dehydrogenase

In research: L-threonine 3-dehydrogenase 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 L-threonine 3-dehydrogenase 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: L-threonine 3-dehydrogenase is common in secondary-school and first-year university syllabi. It links to neighbouring topics EC 1.1.1, EC 1.1.1 stubs, Enzymes of known structure, so understanding it makes those chapters shorter.
In everyday life: Look for L-threonine 3-dehydrogenase 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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Frequently asked questions

What is L-threonine 3-dehydrogenase in simple terms?

Why does L-threonine 3-dehydrogenase 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 L-threonine 3-dehydrogenase?

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 L-threonine 3-dehydrogenase.