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 ...


41

The phrase "Breast is best" is a hotly debated one (source: The Guardian and personal communications with many folks). The reason why we don't want to feed infants cow's milk is, however, anything but debated, because Cow's milk does not provide enough: Vitamin E Iron Essential fatty acids And because it contains too much: Protein Sodium Potassium (...


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 ...


26

The list of ingredients on the can mentions "Zuckerkulör," which is caramel colour, which can have 2 kcal/g, according to one producer. Next, there is "Citronensäure," which is citric acid, which can, as other organic acids, have 2-3 kcal/g, according to this source. There is also taurine, which is an amino acid-like compound, so it could, like proteins, ...


20

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 ...


15

I volunteered for 3 years at a large mammal laboratory where we diligently tracked the weight and caloric intake of each of our animals. Diets were weighed out each morning and total calories could be calculated based on the known caloric value of the particular food item. We fed our animals during training sessions and would adjust the individual's food ...


14

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 ...


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 ...


12

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 ...


12

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 ...


11

Bioavailability is a concept which applies to nutrients and drugs which pass through first-pass metabolism, i.e. orally (and to some extent nasally) consumed substances. Anything absorbed in the gut first passes through the liver before reaching the rest of the circulation, and both the gut and liver may metabolise it to some extent. The liver in specific ...


11

The bacteria in the foregut of cud chewing animals (e.g. cows) provide enough B12 and other B vitamins. Uptake of B12 happens mainly in the small intestine. There are lots of bacteria in the human intestine but most fermentation of plant matter happens in the hindgut. Hindgut fermentation also produces B12 but since this happens past the small intestine it ...


11

I can't support this answer with scholarly articles. But it's an interesting question if you think of milk as highly polluted water. Water from a tap (which is what goldfish usually live in) is 'fairly pure', with the naturally occurring minerals sodium, calcium, magnesium and potassium respectively in highest concentrations (varies by location.) Milk, on ...


10

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 ...


10

does the microbiome affect food metabolism? Most definitely (and not surprisingly). The Arumugam paper [1] notes that The drivers of [enterotype 1] seem to derive energy primarily from carbohydrates and proteins through fermentation, … because genes encoding enzymes involved in the degradation of these substrates (galactosidases, hexosaminidases, ...


10

Detritivores consume (eat) detritus. Saprotrophs feed on dead organic matter by the means of extracellular digestion. Saprozoic organisms are protozoans that are saprotrophs. This actually comes from an obsolete classification of plants and animals where bacteria and fungi were grouped with plants and were therefore called saprophytes if they are ...


10

Proteins are made up of amino acids. It isn't particular proteins that are necessary in diet, but particular amino acids. For humans, these come primarily from breaking down the proteins in foods we eat. Essential amino acids are the amino acids that humans cannot synthesize; other amino acids can be synthesized from these, but they do not need to be part ...


9

This is a bit hard because the usual composition statements are a combination of different types of molecules. Most of faeces are, by dry weight, bacteria (30%), undigested food and fiber (30%), fat (10%-20%), inorganic matter( 10-20%), other protein(2-3%). (reference) As you can see the bacterial portion contains proteins (amino acids) and other types of ...


9

There is not very much transport of ions or water through the upper layer of the skin, mainly responsible for that is the stratum corneum (SC). Through this layer you will get only with small lipids and also substances which are able to penetrate the lipid layer of the cells like chloroform or DMSO. I think therefore that it is pretty unlikely that you can ...


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 ...


9

The amino acids asparagine and glutamine have hydrolysable amide groups on their R groups, as shown here: Note the leftmost amide group on both amino acids. When exposed to acid, these groups would hydrolyse, releasing ammonia. This was of interest when people used to determine amino acid compositions by acid hydrolysing purified proteins (example paper ...


9

It boils down to the anatomy. Herbivores are very good at digesting plant matter, which us monogastrics are not particularly good at. Many herbivores (such as ruminants) have large, highly developed gastrointestinal tracts containing symbiotic bacteria to allow them to digest plant matter. Once the cellulose in the plant cell walls is digested, the animal ...


8

Cooking is just a form of digestion. What is digestion? Digestion is the process of breaking down big molecules into smaller molecules. When you cook food you break down big molecules into its small components. Why do we digest food? Think about a long sequence of DNA for example. You eat corn and you have in your body a long sequence of corn DNA. ...


8

The contents of milk differ between species. For your example, cow's milk: Infants fed WCM [Whole Cow's Milk] have low intakes of iron, linoleic acid, and vitamin E, and excessive intakes of sodium, potassium, and protein Calves have different nutrition needs from human babies. Infants who receive cow's milk instead of breastmilk often suffer from iron ...


8

Let's first clarify some concepts. Free fatty acids, including palmitic acid, are not present in animal tissues (or in the diet) to any large extent; they are esterified with glycerol to from triglycerides (fat), which is the storage form. This is a very important distinction, because triglycerides are chemically inert molecules that can be stored in very ...


7

No it is not possible. Humans are heterotrophic organisms, which means that we use organic molecules (i.e., food) as a source of nutrients and energy. We use the nutrients to add mass to our bodies. These nutrients are the familiar carbohydrates, proteins, lipids (fats), etc... During digestion food is broken down into simpler organic nutrient molecules ...


7

Yes, the microbiome affects food metabolism and the diet affects the composition of the microbiome. +1 to Konrad for his response. This is an area of research in which I and colleagues are engaged. Frankly, it is easier to assess the changes to the microbiome based on diet rather than looking at the fecal material to determine (unused) metabolic energy or ...


7

The name used frequently for this phenomenon is "Post-lunch dip". "The post-lunch dip is a real phenomenon that can occur even when the individual has had no lunch and is unaware of the time of day. This dip has its roots in human biology, and may be linked to the size of the 12-hour harmonic in the circadian system. It is certainly exacerbated by a high-...


7

Question: Is it possible for humans to live healthy long lives without eating any type of life, i.e no animals, no plants? First, according to a definition of a living organism(biology-online), milk is not live, because it does not have an ability to reproduce itself, among other... My claim: If you consider milk and honey non-live (no DNA), then, yes, ...


7

One thing to remember when you uproot a plant is that some of the smallest structures break off most readily. What you will usually see after uprooting the plant are the largest parts of the root structure, but there are often smaller parts which have broken off. Root structure is highly variable, but the general idea is that one or more primary trunk-like ...


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