Small Brains Considered - 12

Fig. 1 The Citric Counselors

I. The question

Could the smallest brain be "the citric acid cycle" (Fig. 1)?  

With the help of the wonderful works of art of Celeste Roberge I will contemplate that question.

Let's contemplate and answer "If so, then a group of Carbon, Hydrogen, Nitrogen, Sulfur, Phosphorus, and Oxygen atoms got together and "decided" to become "a cycle."

The cycle begins when a smaller group transfers some of "itself" ("its 2-carbon acetyl group") to another smaller group to make a larger group.

One wonders if that decreased or increased the brain power, because in the end "it" keeps on "thinking" the same thing and doing the same thing.

But "its long­stand­ing sway over our planet's biotic pro­cesses" takes a lot of "molecule-level she­nan­igans", where 'splainin' how these atoms select their "self" (Transformer, The Krebs (Bi)Cycle) is something only those who play with the doll named "Coenzyme A" can "know" for sure (The Doll As Metaphor, 2, 3, 4, 5, 6, 7, 8).

II. The Data

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Oxaloacetate C₄H₄O₅ +
Acetyl-CoA ((C₂₃H₃₈N₇O₁₇P₃S + H₂O) -
CoA-SH (C₂₁H₃₆N₇O₁₆P₃S)) =
Citrate (C₆H₈O₇)

Step 1: The citric acid cycle begins when Coenzyme A transfers its 2-carbon acetyl group to the 4-carbon compound oxaloacetate to form the 6-carbon molecule citrate (C₆H₈O₇).

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Citrate (C₆H₈O₇) --> Isocitrate (C₆H₈O₇)

Step 2: The citrate is rearranged to form an isomeric form, isocitrate (C₆H₈O₇)

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Isocitrate (C₆H₈O₇) --> Alpha-ketoglutarate (C₅H₆O₅)

Step 3: The 6-carbon isocitrate is oxidized and a molecule of carbon dioxide is removed producing the 5-carbon molecule alpha-ketoglutarate. During this oxidation, NAD+is reduced to NADH and H+ (C₅H₆O₅).

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Alpha-ketoglutarate (C₅H₆O₅) --> Succinyl-CoA (C₂₅H₄₀N₇O₁₉P₃S)

Step 4: Alpha-ketoglutarate is oxidized carbon dioxide is removed, and coenzyme A is added to form the 4-carbon compound succinyl-CoA. During this oxidation, NAD+ is reduced to NADH + H+ (C₂₅H₄₀N₇O₁₉P₃S).

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Succinyl-CoA (C₂₅H₄₀N₇O₁₉P₃S) --> Succinate (C₄H₆O₄)

Step 5: CoA is removed from succinyl-CoA to produce succinate. The energy released is used to make guanosine triphosphate (GTP) from guanosine diphosphate (GDP) and Pi by substrate-level phosphorylation. GTP can then be used to make ATP (C₄H₆O₄).

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Succinate (C₄H₆O₄) --> Fumarate (C₄H₄O₄)

Step 6: Succinate is oxidized to fumarate. During this oxidation, FAD is reduced to FADH2 (C₄H₄O₄).

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Fumarate (C₄H₄O₄) --> Malate (C₄H₆O₅)

Step 7: Water is added to fumarate to form malate (C₄H₆O₅).

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Malate (C₄H₆O₅) --> Oxaloacetate C₄H₄O₅

Step 8: Malate is oxidized to produce oxaloacetate, the starting compound of the citric acid cycle. During this oxidation, NAD+ is reduced to NADH + H+ (C₄H₄O₅). 

 

The NADH + H+ and FADH2 carry protons and electrons to the electron transport chain to generate additional ATP by oxidative phosphorylation.

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 III. The Art Of Artifical Thinking

Step 1. Coenzyme A
Contemplates Transferring A
chunk of self

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Step 2. The citrate is rearranged

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Step 3. 6-carbon isocitrate is oxidized
and a molecule of
carbon dioxide is removed

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Step 4. Alpha-ketoglutarate is oxidized
carbon dioxide is removed
and coenzyme A is added to its "self"

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Step 5. CoA is removed
from succinyl-CoA
to produce succinate

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Step 6. Succinate is oxidized
to fumarate

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Step 7: Water is added
to fumarate
to form malate

 

 

 

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Step 8: Malate is oxidized
to produce oxaloacetate
"I AM A CYCLE NOW"

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IV. The Answer

It is not that complicated:

“Teleology is like a mistress to the biologist; he dare not be seen with her in public but cannot live without her.” —J. B. S. Haldane

(Metaphor and Meaning in the Teleological Language of Biology). Watch the video below (spoiler alert "We don't know"), because the most-honest we can be with our words is "we don't know":

Dr. Paul Falkowski

"Andy. Thank you very much, Andy, and thanks for inviting me here. It's a pleasure. So I just want to begin this by thinking about a bridge. In this particular case, it's an obvious bridge. And if you think about evolution, you know where we've come to, but you don't know where we began. So origins of life is one of the most challenging problems facing science. Actually, as my friend and colleague Nick Lane says, it's the black hole of science. It's an embarrassment. And it's a very complicated problem." -Dr. Falkowski

(From transcript, emphasis added).

V. Closing Comments

There are billions of atoms in each of the "rock people" art work by Celeste, yet I could hopefully not convince you that they are contemplating and doing what a handful of atoms are said to be contemplating and doing (deciding to be a cycle).

This is just one example of what the use of teleology does to make "science" into pseudo-science (On The Origin of Genieology - 2).

The next post in this series is here, the previous post in this series is here.