The function of chemistry within the scope of biology; the study of the compounds that occur, and the reactions involving them, in living organisms.
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2answers
41 views
What nutritious insects exist to farm that require the least attention?
What nutritious insects exist to farm that require the least attention? I'm looking to automate simply, in a self regulating way.
Edit: To add detail, I imagine the insects would live densely in a ...
2
votes
1answer
22 views
Why is allolactose the LacI inducer?
For what reason(s) is allolactose, instead of lactose, the "natural" inducer of lac operon repressor?
3
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1answer
53 views
Why is funnel web spider venom so lethal to humans and not so much for other mammals?
According to the information from this article,
People and other primates are exquisitely sensitive to funnel web venom but, intriguingly, other mammals such as mice, rabbits, guineapigs, dogs ...
3
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3answers
134 views
Why do neurones use chemical signalling at synaptic junctions?
Problem. When a neurone fires, it sends an electrical signal that jumps down the axon via the nodes of Ranvier very rapidly. At a synaptic junction, chemical brownian diffusion signalling with ...
1
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0answers
34 views
Electron transport in granal stacks
See paper for distribution of PS-I and PS-II within grana
As explained in the above paper, the PS-I complex is primarily located within non-appressed thylakoid region and stroma lamella, while PS-II ...
1
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0answers
81 views
Is eating salt dangerous for the brain?
I read somewhere that eating a lot of salt will raise blood pressure, which will in turn damage brain tissue. This is because water molecules gather around salt ions, thus making it harder for the ...
4
votes
1answer
37 views
Photosynthesis regulation
I read about the regulation of Calvin cycle by thioredoxin which activates key enzymes essentially by converting disulphide linkages on inactive enzymes into sulfhydryls. Another regulatory mechanism ...
1
vote
1answer
20 views
Can the excessive consumption of mineral water lead to kidney stones or other health issues?
I heard that drinking too much mineral (bottled) water could lead to problems such as kidney stones because of the high amount of minerals in it. Is it true? If so, what is considered to be excessive?
...
1
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1answer
53 views
Breaking of fats
There is a question I encountered.
Why is fat harder to digest ?
A) It has ester bonds.
B) It is not easily soluble in water.
Which is the most appropriate answer?
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1answer
32 views
Do Acyl Carrier Proteins and Conenzyme A have similar reactivity?
In terms of the reactions they undergo are they roughly equivalent groups?
2
votes
1answer
28 views
Are CoA and CoAS the same thing in a compound?
Is CoA-S-R the same as CoA-R, and is CH3C(=O)CoA the same as CH3C(=O)SCoA? Eg. Above is the compound on the right just coenzyme A or is it actually another compound and not just notation?
5
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1answer
129 views
Using ion-exchange chromatography to purify DNA from a cell extract - Is DNA more negatively charged then RNA?
When applying this method we have a glass or plastic column of resin which is positively charged. Then we pour cell extract into the column in order to capture the negatively charged particles which ...
2
votes
0answers
26 views
Excretion of monovalent and divalent ions in sharks
I have heard that sharks excrete $\ce{Na+}$ and $\ce{Cl-}$ by their gill surfaces but divalent ions like magnesium are excreted through feces. What could be the reason behind this?
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0answers
20 views
Eco-plasticware for the Vendor of Fruit Flies : An Analysis into Microhabitats and Their Bioplastic Enclosures [closed]
The title may be a bit over-the-top, but I'd like to know if there are any "specialists" in plant plastics which are to be used as enclosures for fruit fly habitats. These habitats will have a small ...
2
votes
1answer
54 views
Does precipitation influence the UV spec reading?
I have been checking my sample for Hydroxyl radical scavenging activity. I have dissolved Hydrogen peroxide in Phosphate buffer. My sample is clear and reagent is also clear but when I have mixed my ...
-2
votes
0answers
64 views
How come I'm “aware” of having taken paracetamol? [closed]
For as long as I can remember, I've been able to "sense" that I'm on paracetamol. Whenever the drug kicks in, I have a weird sensation in my nose. It's almost as if I can smell the drug.
Is this a ...
6
votes
1answer
91 views
Why does getting certain chemicals in cuts hurt?
More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the ...
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0answers
13 views
Ovalbumin Detection
Is there a practical way to detect whether or not a baked good has egg in it? I'm thinking of something that can be brushed on to evolve a color change. Any help is appreciated.
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votes
1answer
48 views
Amino acid characteristics that determine their chemical properties?
What chemical aspect of amino acids results in their having different properties such that the chemical and physical properties of polypeptides vary with both amino acid content and amino acid order?
...
2
votes
1answer
33 views
What does “rapamycin-sensitive oncogenic transformation” mean?
Can someone explain exactly what "rapamycin-sensitive oncogenic transformation" is? I get that it's a drug that suppresses the immune system but what does it have to do with oncogenic transformation?
...
15
votes
4answers
757 views
Why are there exactly four nucleobases in DNA?
Does someone know why DNA is composed of four nucleobases? In particular, is there an explanation for the number? Why four and not two, or eight?
1
vote
2answers
94 views
PEG-silane treatment: why incubate for 18 hours at 60 degrees Celsius?
I am conducting a biochemistry-related experiment and I have been unable to understand a step which is commonly performed.
My aim in this step is to apply a PEG (Polyethylene glycol) silane layer.
...
0
votes
0answers
42 views
Relationship between biomass and net primary productivity
I want to do validation on simulated net primary productivity. But I don't have measured NPP data, Eddy covariance flux measurement data. I have only field measurement biomass data. So can I directly ...
0
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0answers
27 views
How do cells slowly degrade 5,5'-dibromo-4,4'-dichloro-indigo?
5,5'-dibromo-4,4'-dichloro-indigo is the product of X-gal cleavage, often used as a reporter with B-galactosidase. I've made the (unreferenced) observation that it seems as though the blue product ...
2
votes
3answers
62 views
Histidine aromaticity
I understand that the imidazole ring in histidine is aromatic. I also realize that it retains it's aromaticity when protonated.
I am wondering why it is not mentioned at all in basic text books such ...
1
vote
1answer
43 views
What is the use of futile reaction cycling such as Fruc-P to Fruc-BP?
One rate-limiting step of glycolysis is the conversion of Fructose-Phosphate (Fruc-P) to Fructose-Bisphosphate (Fruc-BP), catalysed by Phosphofructokinase (PFK). The reaction involves hydrolysing one ...
1
vote
1answer
80 views
Chemical structure prediction
I'd like to do chemical structure prediction using a known molecule formulas. I'm familiar with de novo protein structure prediction, but are there any programs which will go from formula to structure ...
1
vote
1answer
44 views
How do animals/plants change for each season?
The question pretty much sums it up. How do animals/plants change for each: Spring, Summer, Autumn, and Winter?
A detailed explanation on distinct behaviour and appearance changes would be nice.
2
votes
3answers
50 views
What biochemical molecule viewer allows for changes in amino acids and resulting tertiary structure?
I am familiar with the Jmol, Rasmol and PyMoL softwares, and was recently introduced to BioBlender. However, I am completely unaware if any of these programs (or others) are capable of loading a .pdb ...
9
votes
2answers
2k views
Why is PEG important for efficient yeast transformation?
One way to do an yeast transformation is by using lithium acetate, a single-stranded carrier DNA, and PEG (1). I was wondering why is the polyethylene glycol important for the efficient ...
2
votes
3answers
99 views
Michaelis-Menten Kinetics: Does measuring apparent Km and Vmax take into account competing reactions?
I am learning about why it is important to measure Km and Vmax for each experimental setup because measuring the "apparent" Km and Vmax includes enzyme inhibitions of which one might not be aware.
...
3
votes
1answer
42 views
What molecular processes are involved in pseudopodial extension?
I am curious as to the processes and mechanisms involved in the extension of pseudopodia in amoeba. How does the cell know and control the direction and extent of pseudopodia formation at a molecular ...
1
vote
0answers
39 views
How do omega-3 fatty acids reduce cholesterol at the molecular level?
I have heard that omega-3 fatty acids found in fish are a good way to prevent/reduce cholesterol problems.
My question is how do omega-3 fatty acids do that: what are they doing on a chemical level ...
1
vote
0answers
21 views
What is the translation termination efficiency in mammalian cells?
When I express proteins in bacteria I put at least two stop codons at the end of the gene to increase the termination efficiency. Is this the case in eukaryotic cells too? If I put a single stop codon ...
1
vote
1answer
85 views
How exactly does marijuana damage brain cells?
I've heard that THC can cause permanent damage to brain cells. I've also heard this reffered to anti drug propaganda. Another theory i've read is that temporary effects reduce intelligence but long ...
4
votes
2answers
139 views
Differences Between Protein Motifs and Protein Domains?
I am in a 300-level molecular biology class and am unclear about this concept and how to delineate motifs versus domains of proteins. Any suggestions would be much obliged.
2
votes
0answers
23 views
How do you store membrane proteins?
We're producing some membrane proteins and they aren't amenable to freeze thaws even when we add glycerol. The proteins are solubilized in detergent above the cmc so they should be in micelle form in ...
5
votes
1answer
121 views
How to Design an siRNA Experiment?
I'm going to undertake an siRNA experiment soon, but I have only read about them. I want to address the role an enzyme plays in processing a protein.
From what I understand, I will need to pick two ...
8
votes
2answers
155 views
Solution based measurement of Solvent-Accessible Surface Area of macromolecules
The Solvent-Accessible Surface Area (SASA) is a valuable metric for looking at protein folding and protein-protein interactions. However, this measurement is typically done by calculating the SASA ...
7
votes
2answers
118 views
During famine, does the human body do anything to prioritize which organs receive nutrients?
When food is scarce, the body slows its metabolism. Are there any other systems or processes that encourage prioritization of organs?
7
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1answer
107 views
How Antioxidants affects Human Metabolism?
I'd like to know how antioxidants affects the human metabolism and which ones are essential for metabolism processes.
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1answer
22 views
Definition of Dye- Reduction Test?
Can some one give a simple explanation or definition on what a dye-reduction test is.
3
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0answers
61 views
What causes adenosine build up in the brain when awake?
Adenosine is an important hormone in sleep regulation. It is postulated that when a person is awake, there is a build up of adenosine in the brain, which inhibits the neurons in the brain, and ...
4
votes
1answer
71 views
What causes humans to be sleepy?
Is there a hormone or group of hormones that regulates when we feel sleepy late at night, or in the morning? Or is sleepiness caused by some other non-hormonal mechanism? (e.g. pure psychological, ...
33
votes
3answers
8k views
Why is uracil used in RNA rather than thymine?
What is the advantage gained by the substitution of thymine with uracil? I have read previously that it is due to thymine being "better protected" and therefore more suited to the storage role of ...
7
votes
1answer
9k views
NADH vs. NADPH: Where is each one used and why that instead of the other?
I know NADH is used in cellular respiration and NADPH is used in photosynthesis. What difference does the phosphate group make that the same one isn't or can't be used for both? Is there a greater ...
17
votes
4answers
3k views
Death because of distilled water consumption
One of my friends said that I would die if I drank distilled water (we were using it in a chemistry experiment) I gave it a go and surprisingly did not die.
I did a bit of Googling and found this
...
0
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0answers
62 views
What are usable Sum formulas for Proteins?
I'm looking for something like this: $C_{13}H_{25}O_7N_3S$
. Obviously it's not about knowing the exact shape or composition of a specific protein, but knowing the relative contents of major chemical ...
0
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0answers
48 views
What metabolite intermediate will accumulate in a mammalian cell-free extracts capable of glycolysis if lactate dehydrogenase is inhibited? [closed]
I know the reaction proceeds as follows:
Pyruvate accepts the electrons from NADH to form lactate. What would be the intermediate in this reaction? Would it be NADH or NAD+?
2
votes
2answers
97 views
What exothermic reaction distinguishes warm blooded animals?
I would appreciate an answer specifically in the form of an exothermic chemical reaction. Namely, the one primarily responsible for generating heat in warm blooded animals that does not take place in ...
