ScienceIQ.com

Proteins Function Through Their Conformation

To produce proteins, cellular structures called ribosomes join together long chains of subunits. A set of 20 different subunits, called amino acids, can be arranged in any order to form a polypeptide that can be thousands of amino acids long. These chains can then loop about each other, or fold, in a variety of ways, but only one of these ways ...

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ProteinConformation
Chemistry

Carbon Dating

As isotopes break down, or decay they give off radiation. Materials that decompose in this way are said to have a 'half-life'. As the quantity of material present decreases, so does the actual rate at ... Continue reading

CarbonDating
Astronomy

Large Asteroid Zooms Safely Past Earth

A mountain-sized asteroid made its closest approach to Earth at 9:35 a.m. Eastern Time on Wednesday, Sept. 29, 2004. Although asteroid 4179 Toutatis came no closer than four times the distance between ... Continue reading

LargeAsteroidZoomsPastEarth
Biology

You Can Learn A Lot From A Microbe.

You can learn a lot from a microbe. Right now, a tiny critter from the Dead Sea is teaching scientists new things about biotechnology, cancer, possible life on other worlds. And that's just for ... Continue reading

YouCanLearnALotFromAMicrobe
Biology

A Sweaty Subject

When human body temperature rises, tiny muscles around the sweat glands in the skin contract, squeezing perspiration - better known as sweat - out through the pores. Sweat is about 99 percent water. ... Continue reading

Sweat

Yes! We Have New Bananas

YesWeHaveNewBananasDid you know that a plant disease determined what banana variety is in your market? Bananas, which originated in Africa and are now grown in every tropical region, are perhaps the most popular fruit in the world. It is the most popular fruit in the U.S. even though we import nearly all of them. In addition to dessert bananas, the banana family also includes plantains, cooking bananas and abaca, a fiber plant called Manilla hemp. For many years the most popular banana sold in the United States was the variety 'Gros Michel', a preferred banana for shipping. However, 'Gros Michel' is very susceptible to Panama disease, a vascular wilt caused by a soil fungus, Fusarium oxysporum f. sp. cubense. It kills the banana plants by infecting the xylem (the water-conducting tissue) and destroying the plant's ability to distribute water and minerals to its tissues.

For a long time, banana growers moved their plantations to new fields to escape the disease, but as these new plantations became infected the growers eventually ran out of new ground. As a result many 'Gros Michel' plantings were converted to the more resistant 'Cavendish' varieties, even though in time these bananas also became diseased. So this disease has determined what banana you can buy.

Panama disease, also known as Fusarium wilt, is believed to have originated in Asia but gets it name from the damage it caused to banana plantations in Panama, as well as in other Central American countries, in the early 1900s. Bananas must be replanted after fruit production. They are not perennial trees. Since bananas are propagated vegetatively by suckers from the base of the plant, the fungus rapidly spread throughout banana growing areas. Once in the soil, the fungus can survive for many years and is spread further by machinery, contaminated soil and water, and by other physical means.