The study of chemistry within the scope of biology: the compounds that occur and the reactions involving them in living organisms.

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54 views

How do animals with fur get enough sunlight to produce vitamin-D? [duplicate]

How is vitamin D synthesized in animals with fur; how do the cells get enough sunlight? If vitamin-D cannot be synthesized because of limited sunlight reaching the skin, do these animals have to ...
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1answer
92 views

Difference between negative allosteric regulation and non-competitive inhibition

Both connect to some site other than the active site which controls the shape of the active site and causes the enzyme to be less active. So what is the difference?
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1answer
39 views

How does cytochrome c oxidase inhibition cause cell death?

I realise the inhibition of cytochrome c oxidase prevents the release of H+ ions into the intermembrane space, and that the ion gradient is required for ATP synthase action. However, I'm not sure how ...
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2answers
22 views

Can an enzyme be activated without allosteric inhibition or activation?

Are there ways by which an enzyme may be activated or inhibited by non substrate molecules other than allosteric activation or inhibition?
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1answer
34 views

BWA-MEM single strand or doublestrand alignment

In whole genome secondary analysis does BWA-MEM use a double stranded fasta reference or are reads aligned to only one, single stranded fasta reference?
3
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1answer
133 views

Why does Citric Acid occur in Citrus fruits?

Why is there so much citric acid in citrus fruits? And how did it evolve i.e. what did it come from? Is it a by-product of the ripening process? Why have citrus fruit evolved a particularly high ...
6
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1answer
39 views

Why aren't plants and animals capable of assimilating $\ce{N2}$ directly from the atmosphere?

From a E-book written by Hungary scientists, the reason is $\ce{N2}$ is inert. Is this correct? How does the chemical properties of gas species ($\ce{SO2}$, $\ce{O2}$, $\ce{NH3}$, etc) ...
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1answer
76 views

What causes the opaque green colour in Lepidoptera?

Link here to what I mean by 'opaque' colouration on the insect, the colour intensity remains constant despite changes in light intensity and angle (not shown by the picture but the moth exhibits this ...
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24 views

Determination of Ageing by ECG inclusions/exclusions?

I am studying ageing and considering ECG signal because of its high sensitivity in theory (escardio). Some factors Sensitivity Gender Medical treatment ... Benchmark: RTG dental + wrist ...
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16 views

Panel 9 urine/ prescribed ADDERRALL XR [closed]

My doctor conducted a Genesight test, finding out that I am an ultra rapid metabolized. Often times, my body will metabolize my medications before they enter my system. Thus is why my prescriptions, ...
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0answers
113 views

How do CAM plants keep stomata closed by day and open at night?

I understand how plants open stomata, with the H+ ion removal and the resulting K+ ion influx in the guard cells to induce turgor (wikipedia article here), though not how this process relates to ...
4
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1answer
906 views

How does a Plasmodium move?

Plasmodium sp. does not have any locomotory organs. So, how does it move? What biochemical process allows it to move?
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1answer
46 views

Why is metabolism of ethanol catabolism? Could it be also detoxification?

Detoxification is the physiological or medicinal removal of toxic substances from a living organism, including the human body, which is mainly carried out by the liver. Additionally, it can refer to ...
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8 views

Is there a deblocking aminopeptidase without normal aminopeptidase activity?

The deblocking aminopeptidase is a unique exo-type aminopeptidase that liberates blocking groups (formyl, acetyl, and myristyl) from proteins and peptides. However, according to this paper, it has two ...
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1answer
27 views

How are the two ATPs (properly 1.5 though) formed from oxidation of 1 FADH2?

Each ATP Synthase has three sites for binding three sets of ADP and Pi, so when the H+ pass through the a and c subunits are they (3 ATPs) not produced for FADH2 substrate? Besides is the ...
3
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1answer
92 views

How many protons are pumped out per pair of electrons from NADH in oxidative phosphorylation?

I have searched the web and found that 10 protons are suppose to get pumped out during the electron cycle, but i'm a bit confused. I'm trying to count, for every complex(1/3/4), the number of protons ...
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1answer
49 views

What is meant by electron transfer potential?

I was reading a text and came across the term. What does it mean? The sentence said 'The driving force of oxidative phosphorylation is the electron transfer potential of NADH or FADH2 relative to that ...
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0answers
24 views

Is it possible to separate the binding and catalysis of an enzyme in two steps?

Is it possible to do the following: Enzyme E binds to its substrate S without catalysis; Add a controllable stimulus, such as light, adding or removing chemicals; The enzymatic reaction is triggered ...
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0answers
33 views

What are other creatures or plants that leave “recommendations” as ants? [closed]

I'm working on a Semantic Recommendation Systems. In the state-of-the-art, I state the fact that even animals, such as ants, using some kind of recommendations by leaving markers, which are chemical ...
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1answer
56 views

How difficult is it to make a shRNA/miRNA/siRNA to silence/knockdown NaV1.7 voltage gated sodium channels in humans?

There have been various research projects that experimented with shRNA/miRNA/siRNA to specifically silence/knockdown NaV1.7 voltage gated sodium channels in small animals like rats & guinea pigs. ...
4
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1answer
50 views

Is HSV-vector-mediated miRNA expression in dorsal root ganglia stable?

My question is on the following article: "Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy" My question is, do ...
6
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2answers
204 views

At any given moment, how much energy is stored in the human body as ATP?

At any given moment, approximately how much energy is stored in the human body as ATP in the ADP-P-bond? This of course depends on what type of cell it is and the activity of the individual in ...
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0answers
33 views

Assays to determine competitive binding versus non-competitive

I'm looking for both simple and complex assays or technologies than can be used to determine if two competing molecules are competitive or noncompetitive. I figure xray crystallography is a clear ...
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2answers
272 views

How many ATP are formed?

What is the number of ATP molecules formed during the photosynthetic processes which consume 8 molecules of $\text{H}_2\text{O}$ due to noncyclic electron transport and subsequent ...
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1answer
56 views

Why do raw prawns turn red after sitting in vinegar?

Yesterday morning I put some raw prawns (shell removed) into vinegar (more specific this one), and put them in fridge. When I came back at night all of them turned red, which looks cooked, except ...
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1answer
61 views

Where is sialic group in gangliosides that form ABO blood groups?

A ganglioside is a molecule composed of a glycosphingolipid (ceramide and oligosaccharide) with one or more sialic acids (e.g. n-acetylneuraminic acid, NANA) linked on the sugar chain. (source: ...
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1answer
74 views

Is a fat-soluble vitamin a lipid?

I read in a chemistry book that a steroid is a class of lipids, and that the fat-soluble vitamins like vitamin D are part of steroids. So is a fat-soluble vitamin a lipid? This makes me confused as ...
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23 views

How do microbes develop resistance to anitmicrobial peptides?

I would like to better understand how bacteria use the "strategy" of alternations to lipid A and membrane proteins in order to resist antimicrobial peptides of the immune system? It is my ...
3
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1answer
58 views

Do we actually know the molecular dynamics of any enzyme?

That is right, is there a limitation, say Heisenberg's uncertainty principle or something that limits our understanding of machinery of enzymes at atomic level? Can we know how do they actually work? ...
2
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1answer
41 views

Differences among competent cells?

What are the differences among the following competent cells DH5 alpha, Nove blue, and BL21? Why some of them are for cloning and others are for protein expression? Any references where I could find ...
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1answer
76 views

How the chaotropic agents help in purification of DNA molecule?

Those plants which are rich in secondary metabolites and polysaccharides DNA isolation can be done using certain chaotropic agents? can any one explain how it works?
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0answers
27 views

What do the cholinergic system and protein kinase A pathways have to do with inflammation?

In the middle of a comprehensive review of all experimental research to date related to my graduation topic, I have run into a little bump in terms of how these pathways affect inflammation, and how ...
5
votes
1answer
141 views

What would happen if Carbon-14 was in a glucose molecule and decayed into Nitrogen?

This interested me because of Melvin Calvin's experiment with photosynthesis where he used radioactive Carbon-14. If a plant used it as a reactant to make glucose, and that Carbon-14 decayed into ...
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0answers
22 views

About electrons returning to photosystem I when supply of NADP runs out in photosynthesis

According to my textbook, in photosynthesis, when the supply of NADP runs out, electrons from photosystem I return to the electron transport chain that links the 2 photosystems and flow back to ...
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1answer
82 views

About acetyl-coA in the Krebs Cycle of respiration

In respiration, Krebs cycle starts with acetyl coenzyme A which is made from pyruvate. However, it is said that the cycle keeps repeat it self with oxaloacetate turning back to citrate and cycle ...
4
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2answers
327 views

Why are human titin and mice titin considered the same protein?

I have a book that says: In humans titin is a chain of 34,350 amino acids, but in mice it is even longer with 35,213 amino acids. If two polypeptides had different amino acid sequence lengths, ...
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1answer
62 views

Why are nucleic acids negatively charged at physiological pH? [closed]

Why do nucleic acids and mononucleotides have a negative charge physiological ph?
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0answers
32 views

Where can I find the pathway for cAMP signaling in Dictyostelium?

I wanted the cyclic-AMP signaling pathway network of social amoeba Dictyostelium discoideum (which is necessary for the understanding of its "aggregation" life cycle) with rate constants and other ...
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0answers
19 views

Membrane-partitioning free energy [closed]

What is membrane-partitioning free energy? Can we look for difference in free energy upon partitioning in GROMACS? What are the methods I would need to use to determine the free energy of ...
3
votes
1answer
101 views

Why is photosynthesis so complex?

Actually, what is the need of such long procedure? As much as I have understood, the sole purpose of photosynthesis is to synthesize carbohydrates, which is only used for energy storage. So, why don't ...
3
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1answer
102 views

The effects of auto-brewery syndrome

Why are some people affected so differently by auto-brewery syndrome differently if the syndrome seems to be caused by the single organism saccharomyces cerevisiae? It is known that the syndrome has ...
0
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1answer
44 views

Why does vitamin D need to be exogenous?

Vitamin D is a either a hormone or a precursor to hormones. It is very unlike any other vitamins, which are either cofactors or antioxidants, or may be other chemicals necessarily performing catalytic ...
2
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1answer
142 views

Is honey in hot green tea unsafe?

I used Google to try to figure out what kind of mixture honey has with hot water, and I found several Ayurvedic sources claiming that honey in hot water is toxic. For example: Honey – NEVER Put It ...
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1answer
42 views

Stabilizing forces between the protein sequences?

we know that Protein structures from secondary to Quaternary are maintained by noncovalent or weak interactions including electrostatic interactions,van der Waals forces & hydrogen bonding. What ...
3
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0answers
56 views

What is the advantage of using plant-derived antibacterials rather than bacteria-derived antibacterials?

So obviously we have a big problem with antibiotic resistance. Most of our antibiotics originate from bacteria themselves (or are synthetic variations on scaffolds which originate from bacteria). I ...
2
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1answer
499 views

Difference between protein channels, protein carriers and protein pumps?

I'm revising for my biology exam and I don't fully comprehend the difference between protein channels, carriers and pumps. I know that: Protein channels do not require ATP (passive transport) The ...
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1answer
70 views

Advocate for the pop-culture idea of withholding vaccination [closed]

While it is widely accepted that vaccination is preferable to not vaccinating, would anyone like to give a shot at providing evidence in favor of not vaccinating? Anything goes.
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0answers
25 views

enzyme extraction protocol for papain

I am trying to work on fab fragments by digesting whole IgG with papain but finding it difficult finding a protocol for extraction of papain. Can somebody help me with a simple protocol, if per chance ...
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0answers
18 views

Yew seed dormancy reduction

Yew seeds have very long dormancy when artificially planted. They are also adapted to passage through digestive systems of animals that eat/transport them. But could the dormancy be shorter (or the ...
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2answers
56 views

In what two ways is ATP used in coupled reactions?

I already have down "A coupled reaction is when leftover energy from a reaction fuels a reaction that needs more energy. ATP can break apart to transform into something new and use the energy created ...