The process in which energy is liberated from organic molecules producing ATP
16
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4answers
1k views
What does the human body use oxygen for besides the final electron acceptor in the electron transport chain?
My biology teachers never explained why animals need to breathe oxygen, just that we organisms die if we don't get oxygen for too long. Maybe one of them happened to mention that its used to make ATP. ...
14
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1answer
173 views
How fast does the rotor in ATP synthase spin?
I'm sure the exact frequency varies, but does anyone know roughly how many revolutions per minute / second the rotating center part makes?
12
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1answer
484 views
Why do neurons die so quickly (relative to other cells) when deprived of oxygen?
This question could be considered a follow-up question to Why is a lack of oxygen fatal to cells?, although the top answer there does not address why damage starts to pop in.
The answer says this:
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11
votes
3answers
349 views
Why do red blood cells contain haemoglobin and not myoglobin?
So I am reading about muscles and I come across myoglobin. It has a much higher affinity for oxygen than haemoglobin. So why have animals evolved to have haemoglobin in red blood cells, rather than ...
11
votes
1answer
382 views
Given ATP synthase's structure, how can 3.33 protons ultimately synthesize one and only one ATP?
I am familiar with the structure and function of ATP synthase, but one small detail doesn't seem to make sense. It also happens to be a detail that seems very hard to express.
Depending on the ...
10
votes
2answers
268 views
Could hydrogen replace oxygen in cellular respiration?
I was wondering what oxygen actually does in the body. I have seen a few answers to other questions that involve the electron chain and I am really not sure what that is. So I was wondering what ...
10
votes
3answers
255 views
Where does the 'C' in exhaled CO2 mostly come from?
When a human being exhales $CO_2$, what is, by the numbers, the main source of carbon atoms exiting the body in this way? I mean what class of cells, or which tissues are the biggest on a pie chart of ...
10
votes
2answers
1k views
Why is a lack of oxygen fatal to cells?
In animals temporary anaerobic respiration leads to the breakdown of the pyruvate formed by glycolysis into lactate. The buildup of lactate in the bloodstream is accompanied by a large number of ...
9
votes
1answer
612 views
Do fish break a water molecule to absorb oxygen?
How do fish separate oxygen from H20 & consume it? Do they break the water molecule and absorb the oxygen only?
9
votes
3answers
599 views
Where is the line between Anaerobic and Aerobic?
I am well aware of traditional anaerobic respiration (lactic acid or alcohol produced - no Krebs cycle) and traditional aerobic respiration (O2 is used at the end of the Citric acid cycle).
I am ...
9
votes
2answers
268 views
Do mitochondria simply automatically convert glucose to ATP?
I wonder whether there is any intelligent decision-making in mitochondria in the timing of their operation.
Do they simply begin ATP production as soon as the correct reactants are present?
Or, ...
7
votes
1answer
8k views
NADH vs. NADPH: Where is each one used and why that instead of the other?
I know NADH is used in cellular respiration and NADPH is used in photosynthesis. What difference does the phosphate group make that the same one isn't or can't be used for both? Is there a greater ...
7
votes
1answer
341 views
How do prokaryotes perform cellular respiration without membrane-bound organelles?
In order to survive, prokaryotes such as bacteria need to produce energy from food such as glucose. In eukaryotic cells, respiration is performed by mitochondria, but prokaryotic cells do not have ...
7
votes
1answer
90 views
What preceded ATP synthase?
ATP Synthase is ubiquitous throughout life on earth and so most probably evolved within the last universal common ancestor (LUCA) before that lineage diversified into the various kingdoms of life.
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7
votes
1answer
38 views
Cell Respiration and Oxidative Phosphorylation
Why and how does the proton travelling through the stalked particle in the inner mitochondrial membrane, cause a conformational change in the ATPase?
7
votes
2answers
416 views
What effect does ambient temperature have on the cardiovascular system?
I am sorry if this is not appropriate for this site, but I think it fits so I am asking it here:
I went for a run yesterday, and it was about -8 degrees Celsius. I was wearing a couple pairs of ...
5
votes
1answer
484 views
How does the enzyme ATP Synthase use a proton concentration gradient to make ATP?
I understand what the enzyme ATP synthase does, but I'm not exactly sure how it does it. I've heard that it uses rotary catalysis, but how exactly does this work? How is the energy from the H+ ion ...
5
votes
1answer
88 views
Why does muscle tissue have relatively constant AMP + ADP + AMP?
I was going over slides of energy expenditure in muscle cells. It mentions that in muscle tissue, the cell's energy charge ([ATP] / [AMP]) is the principle factor controlling glycolytic activity, and ...
5
votes
1answer
136 views
What is the benefit for cells having the ATP production regulated in mitochondria compared to being from the nucleus?
Mitochondria have their own DNA and appear to be loosely connected to the nucleus and it role.
Why are the functions of mitochondria not in the nucleus? Why doesn't the nucleus control the ...
4
votes
1answer
44 views
How is respiration an unbalanced equation
The equation for respiration is C6H12O6+6O2→6CO2+6H2O+36ATP. The chemical formula for ATP is C10H16N5O13P3. How is this possible, since it violates the law of conservation of mass because it is ...
4
votes
1answer
234 views
Is there a relationship between efficiency of cellular metabolism and warm-blooded-ness?
My BIO 101 book states that when human cells convert glucose to ATP, the process is only approx 35% efficient, and much of the potential energy is lost as heat. However, that heat is useful to us in ...
3
votes
2answers
880 views
Is there an evolutionary reason for the 5 electron transport complexes in plants and animals?
The electron transport chains of both the light reactions of photosynthesis (in plants) and oxidative phosphorylation (in animals) both contain 5 complexes including ATP synthase, as shown below.
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2
votes
1answer
35 views
ATP in Glycolysis Vs Gluconeogenesis
In glycolysis, the conversion of glucose to pyruvate results in a net gain of 2ATP molecules. In gluconeogenesis however, the conversion of pyruvate back to glucose requres 6ATP molecules. Why does ...
1
vote
3answers
165 views
Do cold blooded animals generate any heat?
In explaining energy and work to an 8 year-old I said that all conversion of energy generates heat as a by-product. For example, cars generate heat in their engines and running generates heat in our ...
-2
votes
0answers
40 views
How is it possible for animated corpses to continue their activity? [closed]
Recently I was watching the documentary series "The Walking Dead" and it occurred to me that it didn't make sense that the walking dead could keep up their activities for such a long period of time, ...
