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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Sprouted hulless barley producing acetic acid after several days in the fridge

After soaking of naked barley for 1 day, the barly did sprout in a room-temperature environment for 3 days. After having repeated this process for several times, one can say for sure that in a ...
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20 views

Does the source of caffeine affect the biological impact?

I've recently decided to give up my morning coffee in lieu of a caffeine pill. Both are around 200mg (my Tim Horton's XL 4x4 was 240 mg of caffeine) of caffeine. We were talking about the various ...
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1answer
20 views

Concentration of a specific promoter in a cell?

I want to simulate transcription activation by a given transcription factor (TF) with known kinetics. The binding rate $k_{on}$ is given in $\mu M^{-1} s^{-1} $, describing a bimolecular reaction ...
2
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1answer
46 views

What do proton pump inhibitors do?

I know that sodium azide and 2,4-DNPH inhibit proton pumps. The azide is called an inhibitor and 2,4-DNP is called uncoupler. I want to know what's the difference between the mechanisms of action of ...
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33 views

Why do denatured proteins tend to be less soluble than the native protein?

Why do denatured proteins tend to be less soluble than the native protein? In terms of hydrophobic effects, could anyone explain this phenomenon for me?
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6 views

Energy efficiency of carbohydrate > fat conversion

How efficient is the human body in converting surplus carbohydrate into fat? E.g., if you have 100 calories' worth of carbohydrates at the start of the process, how many calories' worth of fat will ...
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1answer
29 views

amount of tRNA and its extra arm

How much of the total RNAs is tRNA? Some say 15% and some 20%. Those percentages came from my different teachers. Which is correct? And what are the functions of the extra arm (variable loop) of tRNA? ...
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15 views

dihedral angles [migrated]

My guide asked me to measure the dihedral angles of a poly-peptide chain.There are 4 atoms in between two planer surface(2 atoms in each plane).(refer dihedral angles wikipedia) There is a formula for ...
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1answer
19 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. Edit 1: I know how much free energy (∆G) is ...
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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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32 views

Molecular Biology and Genetics [closed]

What's the best textbook and online courses to study Molecular biology and genetics for undergrad student?
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1answer
47 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)?
2
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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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0answers
16 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 ...
4
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0answers
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 ...
4
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1answer
71 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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0answers
20 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?
1
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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?
0
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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?
3
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1answer
92 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 ...
4
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1answer
73 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
41 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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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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0answers
64 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 ...
3
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1answer
142 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 ...
3
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0answers
45 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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0answers
22 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
32 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 ...
1
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1answer
52 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
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 ...
5
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2answers
79 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
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 ...
5
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2answers
211 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
33 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: ...
1
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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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0answers
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 ...
3
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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? ...
2
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1answer
37 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
40 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
26 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
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1answer
129 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 ...