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Questions tagged [energy]

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1answer
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Fuel from photosynthesis

I was reading how plants make use of sunlight, CO2 and some other stuff to make energy. So why can't we create artificially engineered bio solar panels which will take sunlight, C02, water and other ...
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54 views

Does our brain use up more ATP after smoking cannabis?

kind of an amateur here. If the firing of the neurons' signals uses up some ATP, and smoking cannabis makes them fire off more quickly, do our brains use up more ATP to sustain that rapid firing?
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How much energy can one muscle contraction deliver?

How much energy is available in a single muscle contraction? I'm guessing the correct units are J/kg, but I'm open to more correct units. I'm looking for work done, not total energy dissipated (not ...
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84 views

Energy consumption of the human brain: thinking vs not thinking [duplicate]

I'm wondering about the human brain's energy consumption at different "uses". If you use a muscle it uses more energy than if you hold it still. Is the brain like this, or is it "always on" like a ...
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1answer
42 views

How does the human body power itself? [closed]

This query can be divided into sub-queries: What form/s of energy does the human body "run" on? Why/for what are these particular forms of energy required? From what can these types of energy be ...
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85 views

Recent research in bioluminescence powering photosynthesis?

In 2013 there was a Chinese study published on "Bioluminescence as a light source for photosynthesis," which is briefly summarized in this Chemistry World article. There was a question on Biology.SE ...
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0answers
75 views

Simplest known form of aerobic glycolysis

What is the simplest known way that an organism performs aerobic glycolysis? In other words, what is the simplest known way known to convert glucose into $\ce{H2O}$ and $\ce{CO2}$, other than by ...
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1answer
169 views

Power consumption of a ATP synthase in Watts

Considering the ATP synthase to be a rotating machine, does anybody know its power consumption and/or power production in Watts? At least roughly, e.g. based on the average chemical energy produced ...
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1answer
178 views

Does the energy from ATP hydrolysis vary among different cells?

I know that when ATP is hydrolyzed into ADP it gives 7.3 kcal/mol. The question is, does this value vary among different types of cells?
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642 views

Glycolytic non-oxidative pathway

I am currently digging in some books to understand the three major metabolic pathways involved in physical training. The most difficult one for me is the glycolytic non-oxidative pathway (also more ...
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2answers
104 views

Is it a valid generalization that kinases catalyse reactions involving energy transfer and utilization?

The Wikipedia entry for kinase states that "a kinase is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules [such as ATP] to specific substrates". ...
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3answers
884 views

Why do (almost) all energy carriers contain adenine?

Unlike this question which is specific to just ATP, this one includes all energy carriers. When thinking of common energy carrying molecules, I can think of Adenosine triphosphate (ATP), Nicotinamide ...
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1answer
485 views

Is some of the energy of food lost during digestion?

I know that chemical energy of food is converted to heat energy to be used by the body in many metabolic reactions. Specifically, I know that the breaking down of bonds is what releases energy. Does ...
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2answers
15k views

Why is a magnesium ion essential for ATP activity in enzymic reactions?

The Wikipedia entry on Magnesium in Biology includes the following: ATP (adenosine triphosphate), the main source of energy in cells, must be bound to a magnesium ion in order to be biologically ...
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570 views

Fatty acid oxidation in adrenal medulla?

Why adrenal medulla can not utilise fatty acids for generation of energy? What could be the benefit for not having ability to use fatty acids? Refrence 1 Refrence 2
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2answers
322 views

Evidence that Attention Deficit Hyperactivity Disorder (ADHD) is caused by too much cellular ATP?

The question is pretty simple — it's just a theory that I remember my biology teacher mentioned long ago and for years now I've wondered about it without ever asking. Some people with attention ...
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1answer
3k views

What is the brain's preferred energy source? Glucose or ketones?

As with all cells in our body, I know that the brain can get fed from both glucose and ketones, so my question is, given both of them, which one would the brain prefer to utilize first?
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2answers
2k views

Where do mushrooms get their energy from?

I'm wondering where field mushrooms get their energy from. I've heard that they can easily grow on soil in a dark room. So, it seems to me that there wouldn't be any photosynthesizing plants from ...
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1answer
69 views

What is meant by increase in information embodied in the system?

From Ecosystem Ecology edited by Sven Erik Jørgensen After the initial capture of energy across a boundary, ecosystem growth and development is possible by an increae of the physical ...
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1answer
283 views

Redox potentials in photosynthesis light dependent stage

In my lecture notes, it states ...there is a significant thermodynamic problem due to the respective redox potentials of the half reactions: H2O<--> 1/2 O2 + 2H+ +2e- pE=+0.82V ...
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3answers
2k views

The effect of depth on net primary production in aquatic ecosystems

The figure shows the relationship between the water depth and net primary production (=P-R). I want to know why the production (P) initially increases with water depth near the surface? I have seen ...
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2answers
1k views

What does “energy transfer in cells” mean?

"ADP and ATP are involved in energy transfer in cells." I know what is ATP and I know how ADP is formed, but I don’t understand what “energy transfer in cells” means.
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3answers
17k views

Does any organism use both photosynthesis and respiration?

Chlorophyll and hemoglobin are very similar molecules, as far as I understand. The important difference being one using an iron atom and the other a magnesium atom. Do any organisms use both to get ...
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1answer
507 views

Why cannot machines use energy stored in a way similar to biological systems' energy storage?

Owing to the generality of the question I am interested merely in key problems so that I could do further reading. As I understand man-made energy storages are significantly less efficient than ...
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How do red blood cells obtain energy without mitochondria? [duplicate]

RBCs don't have mitochondria so there is no Respiratory chain in them. But how does they get energy from Lactate. Because Lactate produce NADH which gives energy only in respiratory chain.
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2answers
237 views

Why do plants create enough energy for the entire ecosystem? [closed]

In my environmental class, we were recently learning about the $10\%$ law that basically says only $10\%$ of the energy goes from one trophic level to the next. This got me thinking about why energy ...
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3answers
1k views

What is the energy produced by the mitochondria? [closed]

I know that the mitochondria is basically the power house of the body, it consumes amino acids, fatty acids, glucose, etc and oxygen. When these molecules meet up in a enzyme, a series of reactions ...
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2answers
99 views

Does food really give our bodies the energies that we have determined by burning them in the lab?

You are likely to have come across numbers like sugars 17kJ/g (4kcal/g) as the energy supposedly available to our bodies after eating. Yet these values have been determined using very artificial means,...
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1answer
75 views

Is there evidence to suggest that sleeping requires more energy than watching TV?

I have heard the claim: sleeping requires more energy than watching TV. I have heard the counter-claim - watching TV requires large amounts of energy. My question is: Is there evidence to ...
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3answers
868 views

Requirement of energy for metabolic processes

Sorry if this is too elementary, but can someone explain why the following reaction can occur without a net influx of energy from some other process? $C_6H_{12}O_6 + 6O_2 \to 6 CO_2+6H_2O$ And why ...
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0answers
735 views

Why do Proteins store energy when the body already contains Carbohydrates and Lipids?

We already know that lipids are a source of long term energy and carbohydrates are much faster energy releasing sources. So why do we need specific proteins within the body to store energy? Are ...
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1answer
878 views

Relative roles of ATP and NADPH in anabolic and other processes

Chemistry isn’t my strong point, but I’m trying to understand why NADPH is said to be the main agent necessary for anabolic reactions, and if NADPH is used for anabolic reactions what is ATP used for? ...
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2answers
204 views

Why do mitochondria waste energy?

In a mitochondria, it makes ATP by using energy from NADH and FADH2 electron to pump H+ into ...
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48 views

How does plant life obey the constraint that the change in Gibbs free energy in a reaction must be negative?

My understanding is that if a reaction takes place, either entropy of the system must rise, or energy must be released from the system as heat, or both. (Citation: paraphrasing from The Vital Question,...
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2answers
788 views

Energy coupling between two spontaneous reactions?

This diagram describes energy coupling between a nonspontaneous reaction (the formation of glutamine from glutamic acid and ammonia) and a spontaneous reaction (the hydrolysis of ATP). I can see that ...
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0answers
170 views

Does reproduction cause aging ? Is aging just a strategy to increase reproductive success in all organisms? [closed]

Background for why I am asking this: I read a book—modern biological theory and experiments on celibacy— which uses life history theory to imply that reproduction is the reason why organisms grow old....
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1answer
84 views

Does the body prioritise the use of available sugar before fat?

Let's say you eat a very unhealthy snack that contains 90% sugar and 10% fat. Would somatic cells not start using the fat for energy until all the sugar is used up? Does the body not use fat at all ...
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0answers
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Mechanism behind energy generation

I recently read about methanogens and methanotrophs. One converts CO2 to methane and vice versa respectively. I can't get exact mechanism for the methanotrophs and I know they can't be reversed ...
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1answer
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What is ATP and why is it said to be a source of energy? [closed]

Is ATP a molecule or a kind of energy. When I studied the active transport, it's said the ATP would release energy to change the carrier protein shape. So confused. Thanks for your help.
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Why is ATP produced in photosynthesis used to synthesize glucose?

In photosynthesis ATP is produced in light-dependent reactions only to go to the Calvin cycle to be turned into glucose to make ATP during respiration: Why isn't this ATP just directly released into ...
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1answer
1k views

Can a cell start a mitosis if it lacks energy or molecules to complete it?

I'm wondering whether a cell can start a mitosis if it lack molecules or energy to fully complete it. From what I'm reading on wikipedia the cell passes most of its time in the interphase in which the ...
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1answer
55 views

How can low cholesterol cause mortality?

I am studying processes 1. stroke, 2. heart disease, and 3. cancer, and their mechanisms associated with low cholesterol which is a result of lowering cholesterol especially in elderly, Low ...
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420 views

How much energy would it cost to synthesize all cholesterol requirements de novo?

Imagine a scenario in which some person is unable to absorb any dietary cholesterol because of some intestinal mutation (for example). Thus, they have no cholesterol available from their diet for ...
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0answers
116 views

How do human cells respond to mechanical pressure such as heel contact during walking?

Basically, I'd like to do a full accounting (inventory, assets, liabilities) of a human cell under mechanical pressure. For example, if in steady-state, does the cell consume more or less energy ...
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1answer
2k views

If oxygen is such a good energy source, why do plants release it?

Why do plants release excess oxygen, rather than consuming it entirely given it is an excellent energy source?
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73 views

Protein modification and ATP consumption

According to wikipedia there exists a lot of ways to modify a protein (post-translationally). Just to mention few: phosphorylation, dephosphorylation, glycosylation... While phosphorylation requires ...
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1answer
689 views

What dangers would the wireless transmission of power through microwaves pose to living organisms?

If we were one day able to harness the power of "wireless electricity", and INTEGRATE it into society, what disadvantages and/or dangers to living organisms would become relevant at that point? To my ...
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1answer
315 views

Energy produced from respiration [closed]

Why is the amount of ATP Produced from anaerobic respiration is less than the amount produced from aerobic respiration?
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1answer
68 views

What would happen if most the fat in your body was rapidly converted into energy in 2 minutes? [closed]

It all started out as an argument I had with my friend.He said that "it would be the equivalent of catching a fire and burning" But all I thought would happen is that you would now be very hyper ...
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Meaning of 'forms of free energy'?

I was doing a practice exam paper and it asked for different 'forms of free energy'. I am a physicist rather then a biologist so 'free energy' to me means Gibb's Free Energy: $$G=H-TS$$ But I cannot ...