The branch of biology, chemistry, and medicine concerned with the study of the adverse effects of chemicals on living organisms.

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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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0answers
34 views

Why does heating kidney beans at a low temperature potentiate the toxicity of phytohaemagglutinin?

I recently found out that red kidney beans contain a relatively high amount of the toxic lectin, phytohaemagglutinin. An article on phytohaemagglutinin on the FDA website states: Several ...
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1answer
81 views

Relationship between toxicity of drugs and negative effects on brain

Are psychoactive drugs with lower lethal doses more neurotoxic (more damaging to the brain)? For example, tetrahydrocannabinol (one of the active components of cannabis) has a much higher lethal dose ...
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0answers
48 views

Is there a metabolic pathway that generates methanol?

I've been looking for help topics about methanol in metabolism. Specifically, I wish to know what is a common dietary component that generates methanol following metabolism and comment on its ...
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1answer
40 views

Why do provitamins-A do not cause Vitamin-A toxicity?

Why do beta-carotene and other provitamins like alpha-carotene not cause vitamin-A toxicity but rather carotenosis (Orange skin) whereas retinal, retinol, and retinoic acid cause vitamin A toxicity ...
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1answer
65 views

Can the liver prioritize it's metabolizing potential?

Let's assume we have two toxins - one of which is routinely metabolized by the liver, and the other is new to the organism (consider for example alcohol in a heavy drinker and any other drug that is ...
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0answers
36 views

Nail polish toxicity studies?

Are there any well-founded studies that authoritatively demonstrate negative effects from the use of nail polish, particularly in children? I've been brought into the fray of a couple of folks who ...
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1answer
54 views

Why are lipid-soluble substances harder to excrete?

I understand why water-soluble substances can be excreted. However, why are they easier to excrete than lipid-soluble substances? Why can’t lipid-soluble substance be excreted just as easily in the ...
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1answer
64 views

Needle-like crystals observed in wild-grape wine under microscope. Potentially harmful?

I recently crushed and strained about thirty pounds of wild grapes to ferment into wine. About a month in, I did a visual inspection of the wine under microscope to try and identify some yeast and ...
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1k 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 ...
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1answer
161 views

Why black and yellow indicates danger?

It is a pretty well-known fact that combination of black and yellow indicates danger or poisonousness. In western society it seems obvious this comes from bees and wasps, but the look to the ...
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2answers
35 views

Is Roundup toxic?

Roundup, as we all know, is a herbicide that kills weeds. It does this by preventing the production of amino acids in plants. One of these amino acids is tyrosine. Tyrosine is a nonessential amino ...
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3answers
4k views

Is nicotine toxic to humans?

More specifically, is nicotine in the concentrations that smokers receive when smoking cigarettes toxic? I know that in great enough concentrations it can be toxic (but then, so can just about ...
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1answer
890 views

Grapefruits and CYP3A4

Grapefruit juice contains furanocoumarins, which irreversibly inhibit CYP3A4. For this reason, when one is taking certain medications it is necessary to not eat grapefruits because the inhibition of ...
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1answer
197 views

IC50 calculation [closed]

I am a computer science student and I'm in an internship at a genomics and biotechnologies research institute. My current task is to calculate the IC50 and the EC50 given a set of data as a table. ...
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2answers
328 views

Do potassium channel blockers affect the resting membrane potential?

I am reading about scorpion venoms and toxins for my bio class and they appear to have a variety of potassium channel blockers. My professor asked "What effect would this have on a neuron?" and ...
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2answers
171 views

Can a fungus become resistant to a chemical such as Potassium Permanganate?

A friend used potassium permanganate solution to treat tinea on the hands/feet but after some initial success, the tinea seems to be making a comeback. Could the fungus develop resistance to potassium ...
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1answer
139 views

Is Araucaria fruit toxic? [closed]

I've had an Araucaria tree in my garden for more than 30 years. Today a fruit fell off the tree. It looks just like this one: I want to know if it is toxic? Can I eat it? If so, how?
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1answer
222 views

Why is Electrical Cardioversion contraindicated in AF and Digitalis Poisoning?

I am thinking why electrical cardioversion is contraindicated in atrial fibrillation with digitalis toxicity/poisoning. Cardiac digitalis is also called digoxin and cardiac glycoside. It is ...
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1answer
99 views

What makes heavy metals toxic?

I'm not sure all heavy metals are toxic, but most are. Some may be present as insoluble compounds, or otherwhise hard to get into an organism, but that's a side aspect. For example, I would count ...
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2answers
124 views

Why are bacteria immune to snake poisons?

In a test I was asked why bacteria are insensitive to snake toxins. Is it their membrane that provides a barrier to the toxins? Or do snake poisons have specific targets and thus cannot bind to ...
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1answer
64 views

What are the mechanistics of stinging nettles?

There is a lot of research on why nettle extracts causes skin irritation and a stinging sensation. However, I cannot find information on how the extract is injected in human skin. Similarly, I haven't ...
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3answers
9k views

Why is hydrofluoric acid so dangerous if it is a weak acid?

I've read that hydrofluoric acid (HF) is extremely dangerous to touch, but what exactly makes it so toxic? It's weak acid ($K_a = 7.2 \times 10^{–4}$) and dissociates approximately 1/1000 as much as ...
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0answers
55 views

If I fall into a pond with an algal bloom, could I die from the cyanotoxins? [closed]

Suppose I fell into a pond with an algal bloom, and swam in it for a bit, but did not ingest any of the pond water (this is a hypothetical btw). Some algal blooms are harmful, containing natural ...
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1answer
83 views

What happens when someone is stung by a jellyfish?

What happens in the human body when someone is stung by a jellyfish; namely a box jelly. Judging by what I have heard about the stings I'm guessing that they involve a neurotoxin. But what is ...
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0answers
77 views

Medical Uses of toxic venom

One interesting thing I recently learned is that venom has medical uses that can actually save lives! But from what I see so far this either applies to venoms from creatures that are not fatal to ...
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1answer
638 views

How does toluene inhalation damage the brain?

We just had a discussion about toluene abuse. It is known, that people inhaling toluene for a long time have significant brain damage, including decreased intelligence. I found that toluene is a ...
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7answers
5k views

Is there anything that is completely non-toxic to humans at any dose?

Lately I have seen a number of unrelated "scientific" debates over whether certain substances should be outlawed because they are toxic to humans. My initial, informal reaction is usually to respond ...
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1answer
53 views

How does Trifluralin kill newly germinating seeds, with almost no effects on established ones?

Trifluralin (2,6-Dinitro-N,N-dipropyl-4-(trifluoromethyl)aniline) is a pre-emergent herbicide used in landscape beds before the application of mulch (my use for it, anyway). It kills the weeds as they ...
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1answer
32 views

How does Isoxaben kill newly germinating seeds, with almost no effects on established ones?

Isoxaben (N-[3-(1-ethyl-1-methylpropyl)-1,2-oxazol-5-yl]-2,6-dimethoxybenzamide) is a pre-emergent herbicide used in landscape beds before the application of mulch (my use for it, anyway). It kills ...
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1answer
73 views

Why doesn't Fenoxaprop-P-ethyl damage cool season lawns?

For controlling bermudagrass, Cynodon dactylon, a serious perennial grassy lawn weed in my area, I use the herbicide Fenoxaprop-P-ethyl. It kills the bermudagrass rather well, without damaging the ...
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1answer
67 views

Why doesn't Clopyralid damage cool season lawn grasses?

I use Clopyralid (3,6-dichloro-2-pyridinecarboxilic acid) to kill broad leaved weeds in lawns. From my understanding, it works by mimicking an auxin which affects plant growth. Naturally this pulls ...
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1answer
142 views

How does Halosulfuron-methyl kill nutsedge, while leaving lawn grass and most weeds undamaged?

I use Halosulfuron-methyl to control yellow and purple nutsedge in lawns. This chemical acts by interfering with the acetolactate synthase enzyme, which quickly slows cell division, and growth at all ...
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1answer
53 views

How can a plant become resistant to glufosinate?

From Wikipedia, the mode of action of the non selective herbicide Glufosinate is: Phosphinothricin is an glutamine synthetase inhibitor that binds to the glutamate site. Glufosinate-treated plants ...
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1answer
78 views

How does Haloxyfop control young grassy weeds in fields of broadleaved crops?

Haloxyfop (haloxyfop-P-methyl) is a selective herbicide used to control grassy weeds in young stages. The mode of action (iirc) is basically inhibition of acetyl CoA carboxylase (ACCase). Why does ...
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1answer
140 views

How does MSMA kill crabgrass with only minimal damage to lawn grasses?

I use MSMA (Monosodium methyl arsenate) to kill crabgrass in lawns. I am not certain of the mode of action. How does this chemical work? How does it target the annual grassy weeds, without ...
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1answer
94 views

How can a plant resist glyphosate (Roundup) herbicide?

In my area, the most common weeds that strongly resists (N-(phosphonomethyl)glycine) (glyphosate) are the horseweed, or mare's tail, Conyza canadensis, and Canada thistle, Cirsium arvense There are ...
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1answer
1k views

Why doesn't the herbicide 2,4-D damage lawn grass?

I sometimes use 2,4-Dichlorophenoxyacetic acid to control broadleaved weeds in lawns. It is selective, and quickly kills the dicot weeds, while other plants are unharmed. 2,4-D is a synthetic ...
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1answer
51 views

What is the most effective way to eliminate silverfish (g. Thysanura) from walls and floorboards?

I've had our home fumigated, but the silverfish seem to return unaffected. Are their eggs unaffected? What's the best way to eliminate them from your home?
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1answer
121 views

Safety of cobalt-chromium and nickel-chromium dental implants

How safe are cobalt-chromium and nickel-chromium alloys used in dental implants (porcelain fused metal)? IARC groups nickel and cobalt metals in group 2B and chromium in group 3 (hexavalent chromium ...
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1answer
69 views

What is this vinca like vine?

What is this vinca like vine? Is it poisonous? 62521 USA Illinois
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1answer
92 views

Poisonous plants, animals, mushrooms: is this always a kind of defense?

I wonder whether developing deadly toxins in the organism's body is always or usually a defensive strategy rather than a by-product.
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1answer
95 views

Is funnel web spider venom poisonous?

Does the venom of the Sydney funnel web spider have to be injected into the bloodstream to have an effect? If the venom was swallowed (e.g. if a spider was eaten), would it still have an effect? Or ...
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0answers
46 views

Persistency of botulinum toxin in environment

There is information about decontamination times here on pages 6 and 7. My specific question is how persistent botulinum toxin is in a natural environment, or alternatively, what is the half life of ...
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1answer
1k views

Does THC excretion increase if urine volume increases?

In regards to the body metabolizing and excreting THC: if urination is increased as a result of drinking lots of fluids, does that mean that more THC is leaving the body? To rephrase the question, is ...
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2answers
3k views

Is pork poisonous?

Besides religious prohibition, there are several non-religious arguments against eating pork. A few of which are: Pigs and swine are so poisonous that you can hardly kill them with strychnine or ...
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1answer
100 views

In which way would the yeast cell cope with the excess amount of methionine in the growth media?

I guess that when there is surplus of methionine in the cell it is incorporated in the TCA cycle as a succinyl CoA, with cysteine as a by-product. But now the cell has the surplus of cysteine. What ...
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2answers
2k views

Does cooking or ripening reduce the concentration of solanine in nightshade?

I recall a story from one of my Botany professors where he encountered a woman picking Solanum dulcamara (nightshade) berries. When he asked her what she was doing with them, she responded that her ...
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2answers
94 views

Why is gastric lavage considered to be helpful only if a patient comes to a hospital within 1 hour of a toxic ingestion?

Why is gastric lavage considered to be helpful only if a patient comes to a hospital within 1 hour of a toxic ingestion? How severe would the effects be if a patient came to the hospital after the ...
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2answers
1k views

Does scratched Teflon coated frying pans contain carcinogens which can cause cancer? [closed]

Is it true that using scratched Teflon-coated pans contain carcinogens, and if so, can they be consumed through the food cooked in them? E.g. The deadly toxins from non-stick frying pans