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tl;dr: Yes, all plants breathe.— I'm not sure whether I understand the question correctly; because all plants use respiration! Some of the organic high-energy substances produced by photosynthesis are later "burnt" to produce energy in the same "respiration" process used by animals, producing CO2. The difference to animals is that green plants ...


23

Animals use oxygen as a chemical energy source because oxygen gas can react with many other compounds to form oxides, which releases energy and happen spontaneously. Both carbon and nitrogen can be made to react with oxygen, but otherwise they are pretty inert. So of all the gasses in the air present at over a fraction of a percent, oxygen is the only ...


18

I'd argue that we do "breathe" all those gases. Air that we inhale (at sea level) is about 78% N$_2$, 20.9% O$_2$, 1% argon, and smaller percentages of CO$_2$, neon, methane, etc. So all those gases are going into the lungs with every breath in. We take up oxygen preferentially because we have hemoglobin to bind O$_2$. When hemoglobin binds the oxygen, it ...


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Overview. This is a very interesting question. The ideas behind this have been around for a while and the methods are covered in great detail elsewhere. The overall answer to the hypothetical question is rather surprising. There may be actually potential benefits to perpetual liquid ventilation for people with certain diseases. Trials so far have not found ...


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There are two uses of the term respiration: physiological respiration and cellular respiration Physiological respiration involves the intake of outside oxygen and its distribution to the tissues of the body. Breathing is a part of physiological respiration and functions to bring oxygen into the lungs and expel carbon dioxide. Cellular respiration is a ...


15

Besides the unicellular organisms cited by other answers (and the fact that plants actually do respiration), there are some animals who are able to get, although indirectly, energy from photosynthesis through symbiosis with photosynthesizing organisms. You can try the spotted salamander Ambystoma maculatum: The spotted salamander is similar to the sea-...


13

Short answer This is a difficult question to answer. As far as I am aware, asphyxiation results in excitotoxicity, which causes unconsciousness, brain damage and eventually, death. Background Asphyxia is a condition of the body that occurs from severely inadequate oxygen supply, or because of excessive carbon dioxide in the body (First Aid and CPR courses)...


11

Breathing is a part of respiration but respiration is not a part of breathing. Breathing is a process through which oxygen is taken into the body for use in respiration. This involves physical movement to take oxygen (into the lungs) and also chemical action (haemoglobin-carries oxygen from lungs to blood and carbon dioxide from blood to lungs). But ...


11

The simple answer to your question is that in the absence of oxygen the electron transport chain stops. (It can't go backwards, that would generate oxygen.) However your assumption that it stops at the last step is incorrect, all the cytochromes are converted to their reduced form, and there is feedback that diverts the NADH elsewhere. The situation is ...


11

The way we were To understand why you may encounter ATP synthase referred to as ATPase, you need to be aware of the historical context — the experimental work that preceded the knowledge of the structure and function of the enzyme complex that we have today. In a nutshell: Original studies of the components of what we now know to be a complex capable of ...


10

The switch from glucose to ketone bodies as the principal blood metabolite accompanies starvation. This prioritizes the heart, which preferentially uses ketone bodies as a fuel (update; actually it's fatty acids, but they're metabolically similar.) This de-prioritizes the brain, which preferentially uses glucose. [edit] I was asked for a source. This is ...


9

The glycogen in the liver begins providing blood glucose. Muscle glycogen is used as fuel by the muscles, fat cells (adipose tissue) release fatty acids to manufacture ketone bodies in the liver and to be used by the brain as fuel, and body proteins are converted to glucose. In short, the body's metabolism shifts to catabolic reactions. If this continues ...


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Hydrogen in breath arises from normal intestinal bacteria, mainly in the colon, which break down (ferment) the undigested nutrients that have passed through the small intestine. Hydrogen is absorbed from the intestine into the blood and exhaled via the lungs. Conditions in which intestinal bacteria produce hydrogen: Normal digestion in which soluble ...


8

According to Wikipedia "In a healthy, young adult, tidal volume is approximately 500 ml per inspiration..." (tidal volume is the volume inspired/expired) Using this figure, together with values for gas composition also taken from Wikipedia, I estimate that in each breath we take in 18 mg O2 (1.1 mmol) and we release 36 mg of CO2 (1.2 mmol) plus 20 mg ...


7

According to the abstract from this paper, the intragastric LD50 of $\Delta^9THC$ (tetrahydrocannabinol) in sesame oil using Fischer rats was 1270 mg/kg. Assuming rats and humans are identical (they're not), for an average-sized adult human weighing 70 kg (~155 lb.), the median lethal dose would be 88.9 grams, or about 3.1 oz. Keep in mind that's 3.1 oz. of ...


7

This reference from CHEST lists 21 clinically measured peak flow rates during various modes of coughing. Of these patients, and for unassisted cough, the highest peak flow is about 4 liters/sec. The human trachea ranges from 13 to 27 mm diameter. The relationship between velocity, $V$ and flow $Q$ is $$ V=\frac{Q}{A}$$ Assume the 4 liters/sec = 4000 cm^3/...


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The first cyanobacteria were probably anaerobic, and this matter seems to be a hot topic of contemporary research. A recently published studya that performed a phylogenetic analysis of various Cyanobacteria genomes states: The most parsimonious inference from these data is that the last common ancestor of the Cyanobacteria did not use oxygen and that ...


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There is of course a pathway that synthesizes NAD+ de novo, usually from tryptophan, aspartic acid or vitamin B3, or salvaged from compounds like nicotinic acid, nicotinamide. You can read more about it here: https://en.wikipedia.org/wiki/Nicotinamide_adenine_dinucleotide#De_novo_production The fact that TCA works in isolated mitochondria is not necessarily ...


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Organisms are classified, not by their behavior, but by their phylogeny (evolutionary relationships). Sponges have unique and complex molecules in their intracellular matrix that developed in a common ancestor of sponges, and are shared with sponges and all other animals. These molecules include collagen, proteoglycans, integrin, and adhesive glycoproteins. ...


6

Nitrogen is much less reactive than oxygen. Indeed, if I haven't totally forgotten my long-ago chemistry courses, most chemical reactions involving N2 are energy-consuming. Thus you get nitrogen compounds produced by lightning, in auto engines, and other places where there's a lot of energy to spare. Oxygen reactions, OTOH, are energy-producing. You ...


6

Assuming the jar is airtight-- I think your oxygen consumption rate may be too high and that 40$\mu l$ per hour$^1$ might be closer but since it's a high figure anyway we can use it. 40 $\mu l$ per minute would be about 2400 $\mu l $/hr. A 12-ounce jar is about 0.355 liters. At sea level, air contains about 20% oxygen so the volume of oxygen in the jar is ...


6

This is more about basic physics than biology. When you hold your breath, you normally take in one last long breath and keep it in as long as possible, Your lungs are therefore already full of gas (remember that the oxygen used by our lungs is only ~22% of the total volume of air you inhale). Therefore, when you release that breath and want to take in a new ...


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An addition to previous answers plus some clarification The term respiration originally meant breathing i.e inhaling and exhaling (See here). It was believed that it is the oxygen and in turn the act of breathing is what lets an organism survive. After substantial research it had been found that, in individual cells it is the ATP production by ...


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AMP is first converted to ADP in the reaction AMP + ATP $\leftrightarrow$ 2 ADP catalyzed by adenylate kinase. So one phophate group is transfered from ATP to AMP, resulting in two ADP molecules. The ADP formed is then used to synthesize ATP as usual, by the mitochondrial ATP synthase or by the glycolysis enzymes. For other nucleotides and ...


6

This is purely a psychological response, and it does not help in decreasing the speed of CO2 level rise. As CO2 level in your blood rises, you instinctively want to breath out the 'bad' air and breath in fresh one. The latter is impossible under water, but the former eases you psychologically a little; you have "started doing something" with your predicament ...


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Roughly, half of the CO2 assimilated annually through photosynthesis is released back to the atmosphere by plant respiration (Gifford, 1994; Amthor, 1995). Source: https://academic.oup.com/aob/article/94/5/647/151785/Plant-Respiration-and-Elevated-Atmospheric-CO2 Furthermore, it appears like plant respiration rates do not change much with changing ...


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Methane is biologically inert and can only act as an asphyxiant at high concentrations by displacing oxygen. An environmental exposure limit has been set at 5,000 ppm, though 10,000 ppm (1%) had no effect: It is obvious that an exposure limit that presents an explosion hazard cannot be recommended, even if it is well below a concentration that would ...


5

Yes, they are mostly exhaled. The carbon, hydrogen and oxygen that the fats are made of recombine to become $CO_2$ and $H_2 O$ and are exhaled. It's the same overall chemical reaction as if the fats / carbohydrates were burnt, except it's by a different pathway, and the energy produced goes (mostly) towards driving other chemical reactions rather than ...


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A similar question was already answered at How do Gram + bacteria use a proton gradient for F-type ATPase? . In those answers, there is a general belief that Gram negative bacteria do not have much control over their intermembrane space pH, because their outer membranes have many porins, such as OmpC, which allows free passage both ways for protons and other ...


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