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10

Anaerobic respiration is a respiration where the final electron acceptor is different than oxygen. The final acceptor can be a less oxidizing than oxygen, like sulfate (SO42-), nitrate (NO3-), or sulfur (S). For example bacteria that use sulfate are obligate anaerobs. The Krebs cycle cannot take place in the absence of oxygen, although oxygen is not ...


9

Here's an illustrated example in neurons: ATP, of course, is generated by aerobic respiration. The critical biochemical reaction in the brain that is halted due to lack of ATP (and therefore O2) is the glutmaine synthetase reaction, which is very important for the metabolism and excretion of nitrogenous wastes: The body uses this reaction to dump excess ...


7

Your question is based on a bit of confusion about electron acceptors that is very common and that drives microbiologists crazy. Energy (as ATP) is generated when electrons are moved from an electron donor to an electron acceptor. In respiration, the electron acceptor is inorganic -- oxygen for aerobic respiration or an inorganic molecule such as sulfate or ...


5

Consider this from the point of view of integrating whole body metabolism. The body operates on a fuel economy built around glucose. Active muscle produces lactate (C3) which is exported to the liver through the bloodstream. Liver converts lactate to glucose (C6) which is then exported to the tissues. What if muscle produced ethanol (C2)? Liver ...


5

There are three worms which have been found in the sediment of the mediterranean seafloor, which not only live without oxygen but also do not tolerate the exposure to oxygen. They belong to the metazoans, for more details see either the report (reference 1) or the original article (reference 2). They reach a size og about 1mm. References: Scientists ...


4

Agree that anaerobic respiration involves the electron transport chain and alternative terminal electron acceptors such as nitrate. However, respiring cells (whether respiring aerobically or anaerobically) can run the Krebs cycle. As long as there is a terminal electron acceptor, the NADH/FADH2 generated by the Krebs cycle can be oxidized back to NAD+ or ...


3

It is not uncommon for cells to have parallel pathways for same outcome. This ensures foolproof response and makes the system robust. E.coli also has another sensor for aerotaxis (Aer and Tsr proteins). See my answer on your previous post and the linked paper. Also look for coherent feed forward network motifs.


3

Energy production starts with glycolysis, which generates NADH and pyruvate. Pyruvate goes to the mitochondria to make more NADH (or FADH2, which is similar to NADH) in the Krebs Cycle. NADH is used to power the electron transport chain, which gives most of the energy the cell uses. The last step of the electron transport chain consumes oxygen (Complex IV ...


3

In relation to the cardio vascular system a combination of adrenaline from exercise and the bodies natural response to the cold causes constriction of blood vessels in the skin and extremities. This helps to reduce heat loss. The movement from running increases the amount of cold air that runs across your body and into your lungs, which would offset the ...


2

I think you are correct to discount your first point as the cellular respiration proceeding to supply your muscles with ATP when running will produce heat anyway, as you say. As to the lungs having to work harder in cold conditions, its an interesting proposition. I would hypothesise that this may indeed be the case: Gas exchange across the lungs occurs ...


2

I think only b.) is true. a. I cannot find evidence that maltose is toxic to yeasts (and I would hardly believe it, because it is a glucose dimer), however I found evidence, that yeasts might need the presence of oxygen to process maltose. 1977 - The Requirement of Oxygen for the Utilization of Maltose, Cellobiose and D-Galactose by Certain Anaerobically ...


1

You're right, the answer is b since the presence of oxygen would lead to aerobic respiration and not fermentation. If maltose was toxic, the yeast wouldn't grow. Proteins are required for growth, but the yeast is growing. Any temperature that is extreme enough to prevent fermentation would also prevent other cellular processes and the yeast wouldn't ...



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