Questions tagged [metabolism]

Metabolism is the set of defined biochemical transformations occurring within the cells of living organisms.

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Apparent paradox in Glucagon action

Glucagon stimulates glycogenolysis and gluconeogenesis, thus increasing plasma glucose concentration — so that tissues get enough glucose at fasting state. However glucagon also inhibits glycolysis. ...
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Why are children more active than adults?

I have observed that children are usually more active than adults. For example, in the morning they get up and start playing, they have their lunch and get up and start running, while as adults they ...
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Do identical twins have the same metabolism rate at birth?

Will monozygotic twins defecate at the same time if fed at the same time during the first weeks of life? They should have the same genetics (and epigenetics) since they are monozygotic and the same ...
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Glycogenolysis & Gluconeogenesis

Is glycogenolysis and Gluconeogenesis is the same in the terms of product formed? This doubt arrived when I was attempting true & false and the question was Glucocorticoids stimulate ...
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Do Termites and Silverfish metabolize cellulose the same way?

I am fascinated with silverfish and would like to understand more about their metabolism. I learned that they can survive on a diet of cotton which is nearly pure cellulose. Do they metabolize ...
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mitochondria has more activity or the numbers of them are more?

If a cell is needing energy more than the other cells, does it mean that it has more mitochondria or the activity of them is more?
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Quantification of various amino acids from bacteria?

I would like to characterise how much of various (uncommon) cytosolic amino acids are produced in bacteria, and was wondering if there are good suggestions of how to go about doing this. I know that ...
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Reverse oxidative phosphorylation?

I noticed that all of the cellular energy production methods that I covered have a fixed ratio of ATP to NAD(P)H out. For example, in the combined process of glycolysis, pyruvate oxidization, and the ...
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effect of amino acid limitation in CHO cells

I would like to know the effect of individual amino acid and their role in CHO cell growth and their effects on their metabolic pathway if any. And also if there is an amino acid which has an effect ...
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Should I consider [H+] as substrate in MCT transport equation?

I'm trying to model the transport of lactate in cells (in both direction via Monocarboxylate transporters): [Lactate]intra + [H+] <----> [Lactate]extra + [H+] I found some data on kinetics of ...
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Which hormones, metabolites, or other molecules build up as the day progresses, other than melatonin and adenosine?

Melatonin and adenosine reach peak levels around midnight/bedtime. I was wondering what other molecules also buildup as the day progresses. Particularly molecules that affect the CNS and/or immune ...
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Is this statement about caterpillars right?

I've read in lots of sites statements like the following from the Sciencing site "Inside the chrysalis of a butterfly, a caterpillar's body turns to liquid form and it is rebuilt as a butterfly." ...
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How does exercising/starved muscle import glucose (released by liver)?

Adrenaline releases glucose from the liver during sport or if starved. This glucose goes to the blood through GLUT2 transporter. But how does it get transported into the muscle cells? GLUT4 is the ...
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Can muscles remake pyruvate from lactic acid, or does it have to go to the liver in the Cori cycle?

When the muscle is exercising, and only anaerobic respiration is done, pyruvate -> lactate to regenerate NAD+. Lactate is then transported out of the muscle and into the liver, to regenerate glucose, ...
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What relation do glycerol-3-P DH and acyl-CoA DH have with Complex II of the ETC?

I am sorry if this may be a purely definitional/nomenclature question. Complex II of the electron transport chain (ETC) would be succinate dehydrogenase, transporting electrons to ubiquinone (and ...
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What makes the cytoplasm a reducing environment?

It is known that the cytoplasm is a "reducing" environment, where disulfide bonds cannot form (will soon be reduced to 2 cysteines) [I'm not putting a link as this is a fact in many biology textbooks]....
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Does an FAD:FADH2 ratio exist in the cytoplasm? (similar to NAD+:NADH ratio?)

I have learned about a lot of enzymes/proteins which are covalently bound to FAD, and use this as an oxidising agent. In vivo, FAD is (almost) always protein bound (very low concentrations of free FMN/...
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Is there any other sources of hydrogen carriers for the Electron Transport Chain other than the 3 main metabolic pathways?

I am learning about the 4 main metabolic pathways for cellular respiration. I learned that NADH and FADH2 hydrogen carriers are essential in the Electron Transport Chain, because they deposit their ...
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Do plants take in the same amount of CO2 as they release?

There are many claims in the media that trees remove more carbon dioxide form the atmosphere than they release back into the atmosphere. By what chemical pathway can this occur? The law that matter is ...
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Why/How do Cyanobacteria Produce Toxins?

I've been doing some research on the versatility of nitrogen-fixing cyanobacteria, particularly of the genus Anabaena, and I often run into safety hazards and have to add extra steps to my procedures ...
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Any phyla in Animalia that does ammonia assimilation?

A key step in nitrogen metabolism is the initial assimilation of inorganic ammonia into amino acids. Are there phyla within Animalia that do assimilation of ammonium (NH4+)? Phyla with symbionts from ...
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Can erythrocytes Function without plasma?

my title is not very specific. So i will proceed to clarify it. I am trying to make sure that the only blood cells in a sample are Erytocytes, since i want to evaluate their metabolism, I am aware ...
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Can the human body store protein?

I am interested to know if a human body can store protein. Absolutely for the bodybuilders, does it really matter if they divide their protein consumption during the day or eat all of it in one meal ...
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Can heterotrophs use anabolism to obtain energy?

With that question I mean: directly. Please bear with me, as I don't know much about Biology or Chemistry (those are my main difficulties while studying). I know that energy that biological beings ...
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Why do patients with type 2 diabetes not show the body wasting seen in type 1 diabetics?

Type 1 diabetes results from the destruction of the cells in the pancreas that produce insulin, while type 2 diabetes is characterized by so-called "insulin resistance", presumably a reduced ...
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How does temperature affect metabolism of warm blooded animals (homeotherms)?

In cold blooded animals (Poikilotherms) the temperature has a profound effect on metabolism. When the external temperature is raised a corresponding rise in internal temperature followed by a rise in ...
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Looking for Older KEGG global map

I'm looking for the global KEGG map from around 2017, so I can follow the corresponding map in this paper (Figure 4) easier. While the current global KEGG map mostly maps, I'm trying to easier figure ...
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Are there any known microbes capable of living in almost pure carbon dioxide?

Some bioengineering is investigated in high carbon dioxide environments. Are there any microbes like bacteria or Archaea capable of living and multiplying in such environments?
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Regulation of the TCA cycle and glycolysis by adenine nucleotides

Why is the tricarboxylic acid cycle regulated by the ADP/ATP ratio as stated in the following quote : Isocitrate dehydrogenase is allosterically stimulated by ADP, which enhances the enzyme's ...
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How much does 10g of glucose raise the blood glucose level?

If you would calculate it: ~5 liters of blood = 50 deciliters 10g glucose = 10000 milligram so the glucose level raises by 10000mg/50dl = 200mg/dl However, it is known that ingesting 10g glucose ...
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What happens to glucose taken up by the liver in type 1 diabetes?

Type 1 diabetes is caused by insufficient insulin production. Unlike in muscle and adipose tissue (GLUT4), glucose uptake by the liver is by GLUT2 and thus insulin-independent. Consequently, under ...
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Why does the liver produce ketone bodies instead of exporting acetyl-CoA from beta-oxidation for use elsewhere?

Under conditions of low oxaloacetate in the liver, acetyl-CoA that cannot be oxidised in the TCA cycle is converted to ketone bodies, which can then be exported for use as fuel in non-gluconeogenetic ...
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How does coffee cause calcium loss in our body?

Recently on radio a doctor advices to reduce the consumption of coffee as it leads to calcium loss(as my mother described). My initial response was: How could such thing be possible? What kind of ...
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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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quantification of glucose utilization in different metabolic processes

Glucose is commonly associated with ATP production. However, only a small fraction of glucose is utilized this way. The intermediates of glycolysis, TCA cycle, etc. are precursors to various ...
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What is the relationship between cell size and metabolism?

What effect does a bigger cell have on its metabolic activity? I understand that bigger cells need more energy, but surely smaller cells may have high metabolic rates too due to their efficiency?
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What happens if an enzyme stops working in the body?

For example, if the enzymes in the digestive system stop working will the digestion still occur as enzymes are only catalysts for the reactions. Thank You
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A biological system to measure time

First of all I am a physicist, so I apologise for my non-existent understanding of basic biology. However, I have what I think is an interesting question and this seems like a good place to ask it... ...
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During weight loss, do we inhale more oxygen?

During weight loss, triglycerides which are composed of carbon, hydrogen and oxygen, are broken down. During respiration, the inhaled $O_2$ is bonded to a carbon atom to form $CO_2$ which we exhale. ...
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Does the arrangement of amino acids in a protein matter for nutrition?

Let's say there are two diets, consisting of entirely different proteins. If you split up all of the proteins from one day of each diet, you'll get the same set of amino acids and the same count of ...
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About the definition of ketogenic amino acid

I am studying biochemistry and have been looking at metabolic network diagrams showing the different intermediates of glycolysis and the citric acid cycle that amino acids can be converted to. I have ...
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May two reactions, that share the same reactant, fire at the same moment?

I'm studying metabolic networks from a bioinformatics point of view, but I guess my question is pretty biological so I thought that maybe here I could get the best answers. So, as the title says I ...
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Can you predict what the metabolites of pipradrol would be? Are they similar to those of methylphenidate? [closed]

As these drugs are structurally very similar, I am curious about how the body would handle them. Ritalinic acid is a major metabolite of methylphenidate, but that's about all I know. Thanks ...
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Does food lose some of its mass in form of energy during metabolism?

I had an argument with someone. I argued that when a cat eats 1 kg of food, the sum of subsequent output (poo + pee + sweat + change of body mass) must be equal to 1 kg. My opponent argued that the ...
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What is a flux control coefficient?

In metabolic control analysis, a number of coefficients are defined, including the flux control coefficients. How is this coefficient defined and what does it measure?
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What enzyme or bacteria could dissolve plastic?

What enzyme or bacteria could dissolve plastic aside from acetone? Preferably, low-cost and environmentally friendly. Any suggestions would be helpful. I'm targeting for thin plastic (low-density ...
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How important is getting enough glucose for maximal brain performance / cognition?

I know from many studies that have been done, that resting versus active use of the brain has relatively similar overall energy expenditure levels. On the other hand, however, we know that the brain ...
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Can radiation exposure cause cancer later in life even if no traces of radioactive material are present in the body anymore?

I had a long-lasting debate with a friend of mine about the Fukushima incident. The question that we tried to solve was if radiation or toxin exposure can cause cancer later in life even if no ...
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What triggers the switch between aerobic and anaerobic respiration?

I understand that when there is a shortage of oxygen cells convert the pyruvic acid from glycolysis to lactic acid to regenerate NAD+. What I don’t understand is how they switch to anaerobic ...
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Could certain drugs enable one to consistently eat above TDEE or BMR without fat gains?

I heard anabolic steroids and stuff like DNP and ephedrine and etc. can somewhat enable one to eat more and get away with it without much or any fat gain, despite eating more than the body would ...

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