Etikettarkiv: Science

Fascinating taste

I am fascinated by the recent advances in the science of the taste buds that we all have. Compared with our smelling sense the taste sense is very different apparently (but they do work togheter to create the experience we call taste when eating, anyone eathing whilsh having their nose congested on the common cold knows this well).

But scientists are very interested in the pure form of taste. So far they have defined the following types of taste buds: bitter, sour, sweet, salt and umami. Umami is something that people like me did not learn about in kindergarten it’s been added later on and is interesting that as recently as this we are discovering a whole new set of tastebuds.

Umami is found in meat, mushrooms, strong cheese and monosodium glutamate (MSG) which is the pure form really. All these are connected to certan genes in our genome to be expressed as alleleles and there are variations amongst the population. There is one gene that controls the sweet tastebuds, one for the salt receptors, one for umami, one for sour and a whopping 30 genes for the bitter taste buds.

The reason for this is that bitterness has in our evolution been a strong signal for unedible plants. We are wandering people and when finding new types of plants the bitterness signals has served us well in telling the edible from the unedible plant life. Over the long term humans developed more and more genes adding to the sophistication of the sense of bitterness helping us cope with what was found when spreading out of Africa.

However it is not failsafe, there are things you can’t eat that will not signal bitterness and since most modern people readily confuse sour and bitter taste it will be difficult to just suddenly start trusting it again. Our food is also much more spicy and complex today compared to what we have eaten before which makes it probably harder for the receptors to help us.

Compare with the sense of smell, we have about 300 genes active for receptors of various smells, and we got about 700 dormant ones. Dogs and cats have many more still active, we have lost them, perhaps because taste is more effective than smell when it comes from differentiating between the edible and the not edible.

Scientists are also investigating if there are certain taste buds dedicated for recognising fatty acids or lipids and possbily metal as well. They have not found conclusive evidence yet but its very exciting. It is not too far-fetched to reason why we have the senses we have when it comes to taste:

  • Sweet tells us there is a high energy content
  • Salt helps us maintain our electrolytes properly
  • Umami helps us find food that is high in proteins
  • Sour has from the beginning been a signal for spoiled foodstuff
  • Bitter means not edible or poisonous

There are also other receptors on the tongue which is not all about taste, for example we have a receptor that activates if the food we put in is above 43°C and tells us it is very hot — with about a 7°C margin before we actually do scold ourselves. Another different receptor is activated when the food is colder than 26°C, not certain what this does yet the studies continues.

Certain chemical substances are activating the hotness receptor also, it reacts for ecsample to capsaicin, the well known substance of chili peppers, and the mind reacts as if the food is actually hot even though it isn’t. Contrariwise the receptor for cold food is activated by menthol. So it is definitely no coincidence that we think of menthol as cool and chili as hot.

And there is a strange receptor that is activated by certain tastes that we experience as sharp, such as horse radish, garlic and brussel sprouts. In humans there is no connection between this receptor and temperature, but in snakes this receptor is activated by infrared heat higher than 26°C. This maybe serves as a possible way of avoiding bushfires long before they can be felt by other means.

Several of these receptors ties into our pain system and we humans we like to tickle those a little now and then, it makes things interesting and therefore we continue to invent interesting dishes in the kitchen, eat chili, garlic and so on.

One thing I have thought about is that the possible alleles (variances in the genome) for the genes expressing these functions in our body is also a reason for that some people does not like certain food stuffs while others are crazy about them. For example if you have a weak umami receptor perhaps you are not so crazy about a bloody steak?

Can you tell I am somewhat fascinated by this subject?

Names to goole are

Abiogenetic Petroleum Formation

A couple of days ago on Swedish television (channel 4) evening news was a kind of revelation to me. It turns out that KTH (the royal science academy in Stockholm) supports research of abiogenetic formation of petroleum.

Basically this means an alternate theory about how the planet’s oil reserves came to be. The generally accepted theory is that biomatter have transformed over time in the bedrock with heat and pressure into petrochemical compounds that we today are pumping (crude oil) and then refining into gasoline, diesel, kerosene, grease and so on.

But the alternate theroy says that there are coal deposists down in the earth that in the lower parts of the mantle are subjected to high temperature and pressure in the absence of oxygene and that all the necessary compounds are there to form oil in large quantities that are then pressed upwards through cracks in the earths crust to the oil deposists we today are tapping in to.

The interesting with this theory is that if it is true then we will probably not have much problem finding and using oil in the future. We may however not chose to do so for other reasons.

Looking around on the internet it seems that this abiogenetic theory of petroleum formation is not so new after all, it has been popular among certain scientists in the Soviet union from the fifties and the scientists here att KTH who do this reasearch are also of russian heritage.

Frontal figure here is professor Vladimir Kutcherov som tillsammans med Anton Kolesnikov och Alexander Goncharov that have shown a process in a laboratory where oil may form without the biomatter compounds that most mainstream scientist believe must be present.


I have found a new software on the net that I really can spend hours and hours toying around with. This is Celestia – a beautiful astronomical and scientifically correct model to the best of our understanding yet of the universe. Celestia works on Windows, Linux and Mac OS X as well.

You quickly learn how to use the zoom in and out features, how to track celestial objects through the sky but the one thing that strikes me the most is how incredibly alone I feel after a while. I have been standing on Phobos and Deimos, looking down on the face of Mars and although they are just small rocks they are quite far away from the planet that they orbit. I have been amazed over how far from the planet some of the satellites of Jupiter and Saturn are and the sheer number of orbiting bodies around Neptune. And then I suddenly stumbled uppon Cassini, the space probe, still going toward the outermost parts of the solar system.

I have traveled to galaxies far beyond a human comprehension and lost myself along clusters too far from the sun that it was impossible to see the Milky Way again. I have discovered the Greater and Lesser Magellan Clouds and amazed that we and Andromeda are so close in a universe on a perverse macro scale.

This my friends are just amazing. And it is freeware. Download, enjoy if you are an Astronomy buff.

All pictures here are taken from the software.

The planet Saturn and moon Tethys and the sun can also be seen here.

The Milky Way galaxy as seen from a distance half-way from here to Andromeda (M31). The green marking is the location of the sun. You are here.
The Milky Way galaxy as seen from a distance half-way from here to Andromeda (M31). The green marking is the location of the sun. You are here.
Sunrise over Mercury
Sunrise over Mercury

The moon "Pan" orbiting Saturn, one of the more mysterious objects in the skies. There are still so many unsolved mysteries about Saturn's rings...
The moon "Pan" orbiting Saturn, one of the more mysterious objects in the skies. There are still so many unsolved mysteries about Saturn's rings...
The planetoid Pluto as seen from one of its moons, Hydra. Anoter moon is seen beyond Pluto, this is Hades.
The planetoid Pluto as seen from one of its moons, Hydra. Anoter moon is seen beyond Pluto, this is Hades.
Passing the moon on my way back to Earth after a long voyage...
Passing the moon on my way back to Earth after a long voyage...

IBM Photographs a molecule

The smallest things requires the biggest cameras, IBM research lab in Zürich have managed to photograph a carbon molecule called pentacene and it is a first time something so small has been depicted like this.

Pentacene is a five benzen ring molecule used in the making of some semi-conductors today, mainly OFET (organic field effect transistors) and similar devices.

The photograph was made possible because on the tip of the microscope a CO (carbon monoxide) molecule was used as a lens.

Incredible stuff.

Nuclear Policy

The Swedish nuclear policy is a strange thing, ever since in 1980 when there was a poll what people thought of nuclear energy (just after the Harrisburg incident mind you) we have had a policy to dismantle and rid the country of nuclear power plants. Of course we have not had that much to replace it with, we do have a fair lot of hydro power plants that work well but that is also a limited resource and the large rivers suiteable for this are mainly already used.

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