Questions tagged [metabolism]
Metabolism is the set of defined biochemical transformations occurring within the cells of living organisms.
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Is Oxygen from chemical sources used for respiration in humans?
Question
Is there theoretical or experimental evidence that oxygen atoms from molecules in the body are 'cycled back' into the respiratory or circulatory system at all?
Possible sources other than air ...
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Does alpha-glycerylphosphorylcholine really cross the Blood–Brain Barrier?
The prevailing argument that alpha-glycerylphosphorylcholine (alpha-GPC) is superior to other choline donors is that it "crosses the blood-brain barrier (BBB)", but I can find no source that ...
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What does it mean when an EC code has a letter in it?
I am looking through a list of EC number of reactions recorded in metanetx.
And I spotted some with letters
2.1.1.hn
1.5.1.M4
2.6.1.am
4.4.1.n
I haven't seen that ...
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Are Freeman Dyson's theories on the origin of life well regarded in the wider field of evolutionary biology?
Freeman Dyson, a well respected Theoretical Physicist, wrote on a range of different topics during his lifetime, including the origin of life and evolutionary biology in his 1985 book Origin of Life (...
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What fraction of O in dry biomass comes from air vs water?
The net reaction of photosynthesis is, to some degree of approximation,
$$
\ce{6CO2 + 6H2O \to C6H12O6 + 6O2}.
$$
My understanding is that the $\ce{O2}$ comes from water rather than the $\ce{CO2}$, so ...
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Why do animals excrete organic nitrogen compounds instead of N2 gas?
Protein metabolism produces ammonia, which needs to be disposed of; but oxidation of ammonia into water and dinitrogen produces energy, while creating urea or uric acid consumes energy, and excreting ...
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Metabolism of Purple non-Sulfur bacteria
I am a high school student who is currently experimenting with hydrogen sulfide absorption using bacteria. I know species of purple sulfur bacteria or green sulfur bacteria are able to oxidize ...
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Why can't a third acetyl-CoA condense with acetoacetyl-CoA in the same way, as two acetyl-CoAs condense in the thiolase reaction?
In the biochemical ketogenesis pathway, acetoacetyl-CoA reacts with acetyl-CoA to form HMG-CoA (3-hydroxy-3-methylglutaryl-CoA), in a reaction catalysed by HMG-CoA synthase.
But why can't acetoacetyl-...
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Human metabolic pathways involving particular proteins
I am currently working on a project that involves analyzing the pathways in which certain proteins are involved. I have compiled a list of proteins, and I am keen to explore the pathways they ...
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Is the Electron Transport Chain a metabolic pathway?
In my textbook, I read the following description relating to the Electron Transport Chain (ETC):
The metabolic pathway through which electrons pass from one carrier to another is called the electron ...
user78919
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Why would decreased temperature be associated with increased cell size, in deep-sea crustaceans (or in general?)
I was reading Wikipedia regarding deep-sea gigantism -- the fact that deep-sea species are often much larger than their shallow-dwelling counterparts. The article said,
Decreasing temperature is ...
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What is the difference between digesting sugar and carbohydrates?
To understand where I'm coming from, first some commonly distributed (mis?)conceptions:
(Obviously to be taken with a big grain of salt because they are somewhat contradictory)
Sugar is bad for your ...
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Which position do retro aldol reactions occur in (comparing glucose and fructose)?
Regarding glycolysis, my text states:
What is the biochemical rationale for the isomerization of glucose 6-phosphate to fructose 6-phosphate and its subsequent phosphorylation to form fructose 1,6-...
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Water-soluble vitamins involved in amino acid metabolism in the citric acid cycle
I have never seen anything comprehensively written about the vitamins necessary to metabolize amino acids through the citric acid cycle and gluconeogenesis pathway other than the following diagram ...
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Metabolic significance of aspartate transaminase in mammalian liver
Aspartate transaminase (aspartate aminotransferase) is an enzyme that is abundant in hepatocytes and catalyses the reaction:
(Modified from https://en.wikipedia.org/wiki/Aspartate_transaminase)
There ...
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