45
votes
Accepted
How are poisons discovered? Does someone have to die/be poisoned from it first?
Alle Dinge sind Gift, und nichts ist ohne Gift, allein die Dosis macht dass ein Ding kein Gift ist (The dose makes the poison) - Paracelsus
Poisons (I'm going to use this as an umbrella term for "...
- 18.3k
29
votes
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Is Fluorine more toxic than Chlorine?
Fluorine is much more reactive than chlorine and would certainly cause more damage to living tissues. You can even check out https://www.youtube.com/watch?v=vtWp45Eewtw for some fun demonstrations of ...
- 1,544
26
votes
Accepted
Why does carbon monoxide have a greater affinity for hemoglobin than oxygen?
Excursion into simple coordination chemistry: Bonding, backbonding and simple orbital schemes
Please refer to Breaking Bioinformatic’s answer for the MO scheme of carbon monoxide, it is very helpful. ...
- 66k
17
votes
Why does carbon monoxide have a greater affinity for hemoglobin than oxygen?
The answer has to do with pi-backbonding.
In essence, the CO molecule has a negative formal charge on the carbon (it's neutral because of the oxygen having a positive formal charge). However, C is ...
- 2,045
16
votes
How are poisons discovered? Does someone have to die/be poisoned from it first?
As you already correctly deduced, the discovery of poisons was in former times quite accidental, but once its potency was discovered, the (mis)use of it was predictable.
It must also be said that our ...
- 341
15
votes
Why does radiocarbon dating only work in nonliving creatures?
There are plenty of good sources online explaining the principle behind radiocarbon dating. For instance, the wikipedia explains:
During its life, a plant or animal is in equilibrium with its ...
- 20.1k
13
votes
Accepted
Has a non-carbon-based form of life been discovered since 2010?
Just because an organism might need a nutrient, whether arsenic or cobalt (which homo sapiens needs for making RBC's) does not mean that the organism is not carbon-based. What had been announced was ...
- 26.5k
13
votes
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How does one tell (or conclude) if a substance is carcinogenic?
How do we tell or suspect one compound to be carcinogenic?
As written in the comments to the question, this the result of large studies on the human population, correlating blood or urine levels of ...
- 6,819
13
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Is Fluorine more toxic than Chlorine?
Fluorine is in the first place much more reactive than chlorine. In contrary to chlorine, it would not damage biological tissues. It would destroy them. Pure fluorine could put the body on self-...
- 34k
12
votes
Accepted
CO poisoning - What I've been taught is a hoax?
Each hemoglobin molecule has 4 subunits (4 hemes each having one iron atom). Each time a molecule (such as oxygen or CO) binds to one subunit, it changes the binding properties of the other subunits. ...
- 39.6k
12
votes
How does calcium carbide artificially ripen fruits?
Technically, there is no difference between naturally ripened fruit and artificially ripened fruit... they're both ripened fruit. I suppose you were looking for some sort of simple chemical test to ...
- 18.3k
12
votes
Etymology of "click chemistry"
Yes, it is detailed here and in numerous other places. It refers to a class of reactions, and does not mean "join."
From the above-cited page on named reactions:
"Click Chemistry" is a term that ...
- 10.5k
11
votes
Why does carbon monoxide have a greater affinity for hemoglobin than oxygen?
I appreciate above answer by BreakingBioinformatics. However I have been looking for the oxidation reactions involving Fe in this case. Found some useful material here. It is based on the textbook, ...
- 1,916
11
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How are poisons discovered? Does someone have to die/be poisoned from it first?
Sometimes poisons are discovered by chance.
At least that is what happened to me.
We were researching on products made with malonodinitrile and enones.
Since I was interested in the mechanism, I used ...
- 4,272
10
votes
Accepted
What could these letters "S" in red circles mean in a biochemical diagram?
It almost certainly refers to the amino acid (residue) serine. The numbers (300, 333, 351) refer to the residue numbers. The COOH at the end signifies the C-terminus of the protein (subunit).
The ...
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10
votes
Is Fluorine more toxic than Chlorine?
From:
Fluorine gas MSDS
Chlorine gas MSDS
Section 11, toxicity:
Product
Result
Species
Dose
Exposure
fluorine
LC50 Inhalation Gas.
Rat
185 ppm
1 hours
chlorine
LC50 Inhalation Gas.
Rat
293 ppm
1 ...
- 1,122
9
votes
Accepted
Is Acrylamide carcinogenic? Why?
Acrylamide is a Michael acceptor. All Michael acceptors are potentially carcinogenic because DNA can act as a Michael donor. This Michael reaction can damage the DNA, which can ultimately develop into ...
- 6,083
9
votes
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Is it possible to make a drug that liquefies heart plaque to treat heart disease?
Plaques are continually being removed from arteries by natural mechanisms within the body. Statin use, when combined with aggressive dietary changes, can slow down the rate of plaque deposition to ...
- 83.3k
9
votes
Accepted
What does the Pi stand for in the reaction for biological nitrogen fixation?
It stands for inorganic phosphate (Pi). When ATP is broken down into ADP, energy is released along with a phosphate. You can visualise this if you look at the structure of ATP. ADP is then also able ...
- 350
9
votes
Etymology of "click chemistry"
Click chemistry is a term coined by K.B. Sharpless in 2001. The original paper "Click Chemistry: Diverse Chemical Function from a Few Good Reactions."[1] describes a set of very well working reactions ...
- 5,662
9
votes
DNA pairs (adenine-thymine, guanine-cytosine)
In Principles of Nucleic Acid Structure, W. Saenger argues that hydrogen-bonded bases contain at least two hydrogen bonds (forming a "cyclic" pattern). Often, there is a tautomeric form possible that ...
- 35.3k
9
votes
Net production of CO2 in plants
Plants are able to store energy as carbohydrates, i.e. they can make more carbohydrates than they need for their metabolism when there is no sunlight, and store it for later use. So the amount of ...
- 635
8
votes
Accepted
When an enzyme is diluted with water, what is slowing down the rate of reaction?
[…] there's the same number of catalase molecule within an undiluted and a diluted solution. Also, seeing as water is not an enzyme inhibitor, […]
Q: Why is dating between a fixed ...
- 43.6k
8
votes
Accepted
Bones of Strontium
Yes, such substitutions are indeed possible and can possibly happen.
This being the case, is it possible to substitute one important element from an object or system, for instance the calcium in ...
- 8,415
8
votes
Why does radiocarbon dating only work in nonliving creatures?
The metabolism of living creatures keeps the dynamic equilibrium of their $\ce{^{14}C/^{12}C}$ ratio with the enviromental $\ce{^{14}C/^{12}C}$ ratio via photosynthesis, breath, food and excrements.
...
- 34k
8
votes
Accepted
How can an Organic chemist know the chemical formula of a natural product she isolated from an organism?
How can an Organic chemist know the chemical formula of a natural product she isolated from an organism?
There are two levels of answers. One is historical and one is modern. Historically, ...
- 36.6k
7
votes
Accepted
How is it that fructose has a different metabolic pathway than glucose but yet glucose is converted to fructose?
The metabolic pathway you are talking about is how fructose is converted into energy and how its concentration in the blood is regulated. It is indeed true that blood fructose level does not affect ...
- 658
7
votes
Why does carbon monoxide have a greater affinity for hemoglobin than oxygen?
The existing answers explain, chemically, why hemoglobin ($\ce{Hb}$) binds $\ce{CO}$ much more strongly than it does $\ce{O2}$. In reading them, you might get the idea that nature evolved $\ce{Hb}$ to ...
- 11.8k
7
votes
Accepted
How do sodium-potassium pumps differentiate between sodium and potassium?
$\ce{Na^+-K^+}$ ATPase (more commonly called the$\ce{Na^+-K^+}$ pump) is a transmembrane protein that consists of two types of subunits: The 1000-residue $\alpha$ subunit contains the enzyme’s ...
- 8,415
7
votes
Accepted
How does DMSO act as a carrier for transdermal transport of large molecules?
Quote taken from the review (1) (and which is also duplicated in Jacob's 2015 "canonical DMSO" book (2, p. 16)):
There is some evidence to suggest that DMSO can increase diffusion
through the
...
- 36.9k
Only top scored, non community-wiki answers of a minimum length are eligible