science

Thermosynthesis

Thermosynthesis 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 Thermosynthesis rather than just read about it. In short: Thermosynthesis is a theoretical mechanism proposed by Anthonie Muller for biological use of the free energy in a temperature gradient to drive energetically uphill anabolic reactions. It makes use of this thermal gradient, or the dissipative structure of convection in this gradient, to drive a microscopic heat engine that performs condensation reactions.

Key takeaways

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

Reference excerpt

Thermosynthesis is a theoretical mechanism proposed by Anthonie Muller for biological use of the free energy in a temperature gradient to drive energetically uphill anabolic reactions. It makes use of this thermal gradient, or the dissipative structure of convection in this gradient, to drive a microscopic heat engine that performs condensation reactions. Thus negative entropy is generated. The components of the biological thermosynthesis machinery concern progenitors of today's ATP synthase, which functions according to the binding change mechanism, driven by chemiosmosis. Resembling primitive free energy generating physico-chemical processes based on temperature-dependent adsorption to inorganic materials such as clay, this simple type of energy conversion is proposed to have sustained the origin of life, including the emergence of the RNA World. For this RNA World it gives a model that describes the stepwise acquisition of the set of transfer RNAs that sustains the genetic code. The phylogenetic tree of extant transfer RNAs is consistent with the idea. Thermosynthesis may still occur in some terrestrial and extraterrestrial environments. However, no organisms are known at present that use thermosynthesis as a source of energy, although it is possible that it might occur in extraterrestrial environments where no light is available, such as on the subsurface ocean that may exist on the moon Europa. Thermosynthesis also permits a simple model for the origin of photosynthesis. It has moreover been used to explain the origin of animals by symbiogenesis of benthic sessile thermosynthesizers at hydrothermal vents during the Snowball Earths of the Precambrian. Preliminary experiments have started to attempt to isolate thermosynthetic organisms.

Muller's Biothermosynthesis A Dutch biochemist and physicist Anthonie Muller wrote many papers on thermosynthesis since 1983. He defined thermosynthesis as: "Biological heat engines working on thermal cycling." also as: "Theoretical biological mechanism for free energy gain from thermal cycling, tentatively stated as the energy source for origin of life." The thermosynthesis concept, biological free energy gain from thermal cycling, is combined with the concept of the RNA World. The resulting overall origin of life model suggests new explanations for the emergence of the genetic code and the ribosome. It is proposed that the first protein named pF(1) obtained the energy to support the RNA World by a thermal variation of F(1) ATP synthase's binding change mechanism. It is further proposed that this pF(1) was the single translation product during the emergence of the genetic machinery. During thermal cycling pF(1) condensed many substrates with broad specificity, yielding NTPs and randomly constituted protein and RNA libraries that contained self-replicating RNA. The smallness of pF(1) permitted the emergence of the genetic machinery by selection of RNA that increased the fraction of pF(1)s in the protein library: (1) an amino acids concatenating progenitor of rRNA bound to (2) a chain of 'positional tRNAs' linked by mutual recognition, and yielded a pF(1) (or its main motif); this positional tRNA set gradually evolved to a set of regular tRNAs functioning according to the genetic code, with concomitant emergence of (3) an mRNA coding for pF(1).

See also Metabolism Oxidative phosphorylation

References

External links [1] Muller, Anthonie W. J. (2005). "Thermosynthesis as energy source for the RNA World: A new model for the origin of life". arXiv:q-bio/0501013. Muller, Anthonie W. J. (2006). "A search for thermosynthesis: Starvation survival in thermally cycled bacteria". arXiv:physics/0604084. Thermosynthesis Niches in the Solar System Detailed description of the process by Dr. Muller himself.

Worked examples

Example 1 — a first encounter with Thermosynthesis

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

In research: Thermosynthesis 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 Thermosynthesis 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: Thermosynthesis 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 Thermosynthesis 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 Thermosynthesis in 20 minutes

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

Frequently asked questions

What is Thermosynthesis in simple terms?

Why does Thermosynthesis 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 Thermosynthesis?

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 Thermosynthesis.