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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11 views

Energy input during ATP Dephosphorylation?

What is the energy input needed to break the phosphor bond during ATP Dephosphorylation? How and when this will occur? Many thanks for your answers.
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6 views

Separate replication origin and terminus vs making them one and the same

The classical picture of bacterial reproduction has a replication origin on one side of the circular chromosome and a replication termination area on the opposite end. This essentially creates two ...
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30 views

Molecular Biology and Genetics [on hold]

What's the best textbook and online courses to study Molecular biology and genetics for undergrad student?
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1answer
44 views

What came first? The DNA or the DNA polymerases?

I know this sounds a lot like chicken and egg question and while the latter has an answer, I am intrigued about the former. A modified form of the question would be, in the course of abiogenesis, ...
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12 views

Hydrophilic vs water soluble? [migrated]

Is the term 'hydrophilic' a synonym of 'water soluble' or can you have a molecule that is water insoluble but hydrophilic (or water soluble and not hydrophilic)?
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21 views

Glucose to Glucose-6-phosphate [duplicate]

What does actually occur- ATP is hydrolysed and esterification between glucose and HPO4^2- (formed as a result of hydrolysis) take place to form Glucose-6-phosphate or nucleophilic attack of O- of ...
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1answer
19 views

Advantage of GCPRs over RTKs or other receptor protein kinases

My book lists two important differences between GCPRs and receptor protein kinases: GCPRs do not directly activate a signal transduction pathway. It only does so indirectly, via a G protein. On the ...
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15 views

Convert flux value in nmol/min/mg protein to nmol/min/cell?

This is a question about unit conversion. I found an experimental measurement of the saturation uptake of glucose in yeast: $$V_\textrm{max} \approx 650 \textrm{nmol}/\textrm{min}/\textrm{mg ...
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32 views

How do disulphide bonds in hair cause curling?

I understand that the asymmetrical distribution of disulphide bonds in hair cause curling, but do not completely understand why this causes an inherent curl on the macroscopic level, for several ...
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1answer
68 views

All-or-nothing-law: law or general principle?

The all-or-nothing principle indicates that a nerve cell fires at maximum potential or not at all, based on a threshold on the stimulus. Is this a statement which is always true, or only ...
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10 views

Conversion of ALP in milligram to IU/L using BCIP/NBT [closed]

For my project, I need to detect the serum enzyme ALP and quantify the concentration by analysing the color formation due to its reaction with BCIP/NBT reagent. I need to obtain a calibration curve, ...
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0answers
19 views

Vitamin E Production and Sun Light [closed]

Do animals with fur need sunlight to produce vitamin E? It it necessary to have sunlight in humans to make it?
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1answer
21 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
26 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
19 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
17 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?
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1answer
91 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 ...
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1answer
70 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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1answer
39 views

What are some enzymes that can be active without cofactor? [closed]

While reading through a section about cofactor I came across the fact that some enzymes require cofactors. What are some examples?
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0answers
19 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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63 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 ...
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1answer
110 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
37 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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0answers
7 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
24 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 ...
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44 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
44 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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21 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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31 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
51 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. ...
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1answer
47 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 ...
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2answers
76 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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27 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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148 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
32 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
43 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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20 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 ...
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1answer
49 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? ...
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1answer
36 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
37 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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24 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 ...
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1answer
127 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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15 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 ...
7
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1answer
70 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 ...
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2answers
303 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
45 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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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
16 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 ...
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1answer
82 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 ...