Hot answers tagged

53

The answer to your question is yes it is certainly possible. At one time it was thought that there was something special about "organic" chemicals which meant that they could not be artificially synthesised out of fundamental elements. In 1828 Frederick Wöhler synthesised urea (CO(NH2)2) which is often taken as the first demonstration that the organic v ...


36

Living organisms can be divided into hetrotrophs and autotrophs. Autotrophs like plants and algae are able to produce complex organic compounds from relatively simple inorganic components. They are satisfied with sunlight, water and other abiotic stuff and do not need to consume "life". We -- along with all other animals -- are not autotrophs, but ...


29

I believe that MattDMo's hypothesis is incorrect. Only one group of ants, the Attini tribe, cultivates fungus as a food source. This group is exclusively a New World group, thought to have originated in the Amazon rainforest and spread out from there. I see from your profile that you are located in India, which is outside the range of the ...


23

To elaborate on A random zoologist's answer, the problem is that the human digestive system does not contain any cellulase enzymes. Cellulases are a class of enzymes that break down cellulose, the chief structural component of plants. You might be able to obtain a small amount of nutrition from grass or other cellulose-rich materials, but as the plant cell ...


21

Even on a purely synthetic diet, your body would still use living cells as an energy source. Our bodies contain more bacterial cells than human, mostly contained in our gut. These microbes process any nutrients we ingest and when they die, we absorb their cellular components as nutrition. The lining of the gut is the most rapidly dividing population of ...


18

Yes, mantises hunt cicadas... Mantis eating cicada. Source: Dreamstime. ...and yes, orioles hunt cicadas too... Oriole eating cicada. Source: Bird Ecology Study Group. .., and what may be more relevant to your idiom: orioles prey on mantises. Oriole eating mantis. Source: Sustainable Adventure.


17

There are a number of papers studying the ability of fungi to metabolize keratin, the primary structural component of nails (as well as skin and hair). Ants are also known to cultivate fungi for nutrients, so this may simply be a case where the ants are bringing food for their "farm animals."


16

The more "dangerous" properties of spicy peppers are chiefly due to capsaicin. Sigma-Aldrich sells purified capsaicin, for which they provide safety information, including an MSDS. Most of it is the usual, unsurprising set of warnings about irritation to eyes and the respiratory system. However, there are LD50 numbers: LD50 Oral - rat - male - 161.2 ...


15

While poison affects not every organism equally, plants did develop some poisons to avoid being eaten. However, if you look at the great multitude of so-called secondary metabolites, most of them are poisonous to either viruses, bacteria, fungi or other microorganisms, or insects, or even other plants. Plant evolution just hasn't had time to adapt to humans. ...


14

The basic reason is osmosis, the tendency of solutes to move from an area of high concentration to one of low concentration across a permeable barrier. So, ingesting large amounts of salt results in a high sodium concentration in the blood stream. This in turn causes water to enter the blood vessels by osmosis. More water in the blood means a greater volume ...


14

Of course eggs are not vegetarian. Eggs are, well, the eggs of chickens (usually). Chickens are animals so their eggs are animal matter as well. Whether or not the egg has been fertilized is completely irrelevant, eggs are chicken just as much as drumsticks are. The color of the egg has nothing at all to do with it. All eggs are, by definition, animal ...


14

Your question is phrased somewhat ambiguously as to whether you're asking about the theoretical possibility, the feasibility, or the practical ability in everyday life. 1) Theoretically, yes. It is chemically possible to produce all substances that humans need to survive without the use of living organisms in the process. In the end, biological systems use ...


10

During putrefaction of animal tissue, lysine is decarboxylated into cadaverine and arginine is decarboxylated into putrescine. These compounds are deemed to be toxic. A serving of meat contains 8 g of protein, corresponding to 640 mg lysine and a little bit less of arginine. Let's go straight and say that a spoiled meat serving contains 640 mg cadaverine ...


10

Evolution is not that simple. There is no selective pressure for a feature if it does not ultimately in some way benefit reproduction or the offspring. Vegetables are healthy for us now because we live much longer than we used to in an environment not dominated by us, and they contain many nutrients which help to sustain a healthy body beyond, say, 50. ...


10

They don't eat little. Consider the volume of milk / food they consume as a ratio of their weight. Quite the contrary they are ravenous machines and their consumption is much higher than an average adult. All cellular energy comes from the hydrolysis of ATP, and the production of ATP comes from the breakdown of glucose. The glucose comes from a sugar found ...


10

First, there are two different isomers of the lactic acid, the L(+)- and the D(-)-form. Both differ in the position of the OH-group in the molecule: Both turn polarized light in different ways, the D(-) to the left and the L(+) to the right. The physiological form of lactic acid for the human body is the L(+) form, which is taken up in the gut and then ...


10

I'm going to focus on the why do carnivores exist part of this question, which should be extendible to answer why humans eat meat. Let's start a thought experiment in which we only allow the consumption of vegetation (plants). In the simple system we have our plants (lettuce) and our herbivores (rabbits). The lettuces have a constant population size, and ...


10

Generally, cold suppresses sweetness. As an example, consider soft drinks that are usually served cold: they taste sweeter when warm (like you said with your examples of drinks). Our taste receptors send a stronger signal to the brain when activated by warmer substances and so the perception of sweetness, in this case, is lessened when we consume cold food ...


9

I wouldn't be suprised if no one has hard data on this. In any case there is more than one answer to this question. Niches are defined more than one way. In the narrowest definition, the niche might be defined as the ability of the different trees to grow in different terrains or be eaten by different animals in the same environment. I can't comment on ...


9

Shortest answer: there's nothing special in human biology, you could totally make it Short answer: Bachelor chow! I would totally buy this stuff if they made it. The closest I have now to bland, flavorless, zero thought/effort food is Wheaties. longer answer: Seriously though, dogfood for humans wouldn't be that hard to make. If you just took everything ...


9

Yes. Rob Rhinehart has developed what he refers to as "a food substitute intended to supply all of a human body's daily nutritional needs, made from powdered starch, rice protein, olive oil, and raw chemical powders" which he calls Soylent. It was developed and tested largely in 2013, crowdfunded late 2013, and is expected to start shipping in 2014. Tests ...


9

Depends on how you define "life"? Is unfertilized chicken eggs alive? What about cow milk? Well there are bacteria in it. What if you get rid of that bacteria? Then some people would not be able to utilize lactose... Also as Bez mentioned rice grains are quiescent, meaning they are in a dormant state and not really "alive" but again depends on how you ...


8

Yes, they are behaving differently because of the lack of nutrients, including lactose, and possibly because of the presence of other chemicals in soy milk that aren't in dairy. Kefir grains are a complex community of different types of lactic acid bacteria and yeasts which metabolize (eat) various nutrients/chemicals in their environment. Because soy milk ...


8

Wheat and other grasses are very significant sources for human nutrition. Grass seeds are digestible; seeds have to digest themselves to sprout, with very little biochemical machinery. Human civilization is founded on the ability to cultivate grass to eat. It is due to pepsin that a cellulase supplement would not help to digest grass stems and leaves. ...


8

I agree with @inf3rno: caffeine is a stimulant that acts on the brain and various other parts of the body (Snyder et al., 1981) and I wish to elaborate on its psychopharmacology. Caffeine's effects in the brain are mediated through adenosine A1 and A2 receptors (Daly et al., 1983). This results in a variety of actions (Fredholm et al., 1999). Most notably, ...


8

There's a fantastic database available from the United States Department of Agriculture that includes almost 9,000 common foods, including their nutritional information. This database is searchable and available from the USDA Agricultural Research Service. Here is a link for the online searchable database. Within the database you are able to search for a ...


7

The likeliest culprit here is fermentation carried out by bacteria present in the milk. Fermentation of a sugar, for example glucose, releases carbon dioxide (a gas) : $$C_{6}H_{12}O_{6} \rightarrow 2 C_{2}H_{5}OH + 2 CO_{2}$$ Since this reaction produces a gas, the gas builds up in the milk carton causing it to bulge. This is not, generally, a good sign, ...


7

Quite a bit can be absorbed through the mouth. Most commonly, starches are broken down to maltose (two glucose molecules formed by a condensation reaction) and are easily absorbed by the bloodstream. A lot of other factors balance into this, ie pH, lipid solubility, and molecular weight. Generally, if a substance is easily dissolved in saliva, it can be ...


7

1 billion hives (at 10,000-50,000 bees/hive this is 10-50 trillion bees) Managed: 100 million hives Based on country-level data from FAO, supplemented for a few countries with Apiservices, in 2011 there were about 80 million managed hives. Because FAO lacks any data for some countries, and other countries under-report (for instance US figures don't ...


7

The reason for this is the oxidation of phenol residues in the banana (for example in the yellow color) which get oxidized by the enzyme Polyphenol oxidase (PPO) to melanins. The scheme (the image is from this website on food browning) looks like this (you can of course also use more complicated substrates): For further information, see these references: ...



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