Questions tagged [energy]

for questions relating to chemical, mechanical, electromagnetic, thermal, kinetic or potential energy or any other energy related directly to biological organisms or biological systems

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Placement of an insectivorous plants in a food chain?

Where can we place an insectivorous plant such as Venus flytrap in a food chain, first or other trophic levels.... because it is a producer as well as consumer?
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1 vote
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What is the relationship between muscle energy consumption, the period over which the contraction occurs and the mechanical work performed?

I'm asking this question with some basic knowledge of physics and general fitness. Suppose you are lifting a still object with mass $m$ from height $h_1$ to height $h_2$ with an arbitrary (straight or ...
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Do quantum mechanical effects such as uncertainty, tunnelling and entanglement play role in the electron transport system of respiration?

The electron transport system of aerobic respiration involves an extensive pathway of electron and proton transfer from one centre to another. Now, since they are quantum mechanical particles, shouldn'...
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3 votes
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Do jellyfish have extra energy reserves for emergencies (a "fight or flight" response)?

My friend is writing a story about jellyfish, and we couldn't find out if jellyfish have the equivalent of a "fight or flight response" or an adrenaline rush. In other words, do they have ...
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1 answer
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Pyruvate dehydrogenase: Apparently anomalous NAD/FAD redox reaction

Below is the mechanism for the reactions of the pyruvate dehydrogen complex, which oxidatively decarboxylates pyruvate and transfers the acetyl group to coenyzme A for further metabolism in the Krebs ...
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2 votes
2 answers
309 views

How many Watt-hours can an electric eel produce in a day?

Electric eels are cited as being about to produce about 860 watts of energy. But I haven't been able to find information on how long they can sustain their charge. https://www.youtube.com/watch?v=...
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5 votes
2 answers
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How come only a handful of animals can do photosynthesis?

As far as I understand, all the energy that living beings rely on comes from the sun. It's processed by plants in photosynthesis. These plants are consumed by herbivores, which in turn are consumed by ...
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2 votes
2 answers
344 views

Do fish depend on plants for survival?

As far as I know, all land life depends on plants for survival. Plants convert sunlight to energy using photosynthesis, herbivores consume plants, and carnivores consume herbivores. All the energy is ...
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Under which conditions is human energy consumption minimized?

Including but not limited to: body state consumed food composition state of the digestive tract diseases wounds sleep coma, etc.; death excluded environment state temperature light pressure, etc. ...
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How is energy stored in the cotransport of molecules down to its electrochemical gradient?

I am talking about symporters and antiporters, that transport usually an amino acid against its concentration gradient while at the same time transport another molecule down its electrochemical or ...
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1 answer
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How to generate electrical current from biological decomposition

I'm working on a project to generate and store small amounts of electrical current by means of decaying organic matter and would like to know: a) Is it possible to generate electrical current from ...
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2 votes
2 answers
395 views

Understanding entropy and the second law of thermodynamics as involved in metabolic processes

My AP biology textbook, (the 10th edition of Campbell Biology) states entropy as being the disorder or randomness of the atoms involved in any matter, but Khan Academy says that this example isn't ...
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When is voltage generated across a membrane?

I'm very confused so bear with me please. Electrogenic pumps are carrier proteins that generate voltage through the movement of ions, right ? When is a voltage generated ? When there's a net ...
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How to calculate grams of fat used during hibernation?

In Humphries et al. 2002. Nature, the authors report number of grams of fat bats use during hibernation. However, their equations results in values in mlO2/g. How can one convert the energy ...
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If bond break absorbs energy, why ATP hydrolysis releases it?

We know that bond formation releases energy and bond break absorbs energy. I still don't figure out why ATP hydrolysis (that breaks a bond between oxygen and phosphorous) releases energy, and it ...
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1 answer
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How does shortage of oxygen halt the NADH dehydrogenase complex?

I understand that in the absence of oxygen the functioning of cytochrome c oxidase stops because it is its substrate. However I don’t understand how stopping cytochrome c oxidase also stops the ...
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1 answer
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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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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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2 votes
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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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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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-2 votes
1 answer
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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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3 votes
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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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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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2 votes
1 answer
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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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1 vote
1 answer
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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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4 votes
2 answers
869 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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4 votes
2 answers
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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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10 votes
3 answers
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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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3 votes
1 answer
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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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3 votes
2 answers
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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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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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4 votes
2 answers
541 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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4 votes
2 answers
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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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3 votes
2 answers
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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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4 votes
1 answer
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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 structure(...
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2 votes
1 answer
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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 NADP+ +2H+ +...
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5 votes
3 answers
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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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3 votes
2 answers
2k 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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16 votes
3 answers
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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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3 votes
1 answer
623 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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2 votes
0 answers
134 views

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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1 vote
2 answers
289 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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0 votes
3 answers
2k 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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5 votes
2 answers
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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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0 votes
1 answer
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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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3 votes
3 answers
1k 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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2 votes
0 answers
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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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3 votes
1 answer
1k 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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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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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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