Archive for the ‘chemistry’ category: Page 148

Oct 28, 2020

Scientists discover new organic compounds that could have helped form the first cells

Posted by in categories: biological, chemistry, evolution

Chemists studying how life started often focus on how modern biopolymers like peptides and nucleic acids contributed, but modern biopolymers don’t form easily without help from living organisms. A possible solution to this paradox is that life started using different components, and many non-biological chemicals were likely abundant in the environment. A new survey conducted by an international team of chemists from the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology and other institutes from Malaysia, the Czech Republic, the U.S. and India, has found that a diverse set of such compounds easily form polymers under primitive environmental conditions, and some even spontaneously form cell-like structures.

Understanding how life started on Earth is one of the most challenging questions seeks to explain. Scientists presently study modern and try to see what aspects of their biochemistry are universal, and thus were probably present in the organisms from which they descended. The best guess is that life has thrived on Earth for at least 3.5 billion of Earth’s 4.5-billion-year history since the planet formed, and most scientists would say life likely began before there is good evidence for its existence. Problematically, since Earth’s surface is dynamic, the earliest traces of life on Earth have not been preserved in the geological record. However, the earliest evidence for life on Earth tells us little about what the earliest organisms were made of, or what was going on inside their cells. “There is clearly a lot left to learn from prebiotic chemistry about how life may have arisen,” says the study’s co-author Jim Cleaves.

A hallmark of life is evolution, and the mechanisms of evolution suggest that common traits can suddenly be displaced by rare and novel mutations which allow mutant organisms to survive better and proliferate, often replacing previously common organisms very rapidly. Paleontological, ecological and laboratory evidence suggests this occurs commonly and quickly. One example is an invasive organism like the dandelion, which was introduced to the Americas from Europe and is now a commo weed causing lawn-concerned homeowners to spend countless hours of effort and dollars to eradicate.

Oct 27, 2020

Study shows how tiny compartments could have preceded cells

Posted by in categories: bioengineering, chemistry

One of the most important questions in science is how life began on Earth.

One theory is that wet-dry cycling on the early Earth—whether through rainy/dry periods, or through phenomena such as geysers—encouraged molecular complexity. The hydration/rehydration cycle is thought to have created conditions that allowed membraneless compartments called complex coacervates to act as homes for chemicals to combine to create life.

Using the Advanced Photon Source at Argonne National Laboratory, scientists in the Pritzker School of Molecular Engineering (PME) at the University of Chicago studied these compartments as they undergo phase changes to understand just what happens inside them during wet-dry cycle.

Oct 27, 2020

Geochemistry and the Origin of Life: From Extraterrestrial Processes, Chemical Evolution on Earth, Fossilized Life’s Records, to Natures of the Extant Life

Posted by in categories: chemistry, evolution

Scientists today are quick to point out that they are still basing their models on life as we know it: Carbon-based and reliant on organic compounds and water…

In 2001, the first author (S.N.) led the publication of a book entitled “Geochemistry and the origin of life” in collaboration with Dr. Andre Brack aiming to figure out geo- and astro-chemical processes essential for the emergence of life. Since then, a great number of research progress has been achieved in the relevant topics from our group and others, ranging from the extraterrestrial inputs of life’s building blocks, the chemical evolution on Earth with the aid of mineral catalysts, to the fossilized records of ancient microorganisms. Here, in addition to summarizing these findings for the origin and early evolution of life, we propose a new hypothesis for the generation and co-evolution of photosynthesis with the redox and photochemical conditions on the Earth’s surface. Besides these bottom-up approaches, we introduce an experimental study on the role of water molecules in the life’s function, focusing on the transition from live, dormant, and dead states through dehydration/hydration. Further spectroscopic studies on the hydrogen bonding behaviors of water molecules in living cells will provide important clues to solve the complex nature of life.

Keywords: building blocks, biopolymers, polymerization, extraterrestrial inputs, mineral surfaces, metabolism, photosynthesis, water, hydrogen bonding (9: 3–10)

Continue reading “Geochemistry and the Origin of Life: From Extraterrestrial Processes, Chemical Evolution on Earth, Fossilized Life’s Records, to Natures of the Extant Life” »

Oct 27, 2020

‘Fireball’ that fell to Earth is full of pristine extraterrestrial organic compounds, scientists say

Posted by in categories: chemistry, space

The meteorite crashed on earth on 2018. But it seems the news just came out. The good news is that it crashed on a frozen lake.

A fireball that fell to Earth in 2018 contains “pristine extraterrestrial organic compounds” that could help tell us how life formed, scientists say.

Continue reading “‘Fireball’ that fell to Earth is full of pristine extraterrestrial organic compounds, scientists say” »

Oct 27, 2020

Water exists on the moon, scientists confirm

Posted by in categories: chemistry, space

Now, Casey Honniball at NASA’s ASA Goddard Space Flight Center in Maryland, US, and colleagues have detected a chemical signature that is unambiguously H2O, by measuring the wavelengths of sunlight reflecting off the moon’s surface. The data was gathered by the Stratospheric Observatory for Infrared Astronomy (Sofia), a modified Boeing 747 carrying a 2.7-metre reflecting telescope.

The water was discovered at high latitudes towards the moon’s south pole in abundances of about 100 to 400 parts per million H2O. “That is quite a lot,” said Mahesh Anand, professor of planetary science and exploration at the Open University in Milton Keynes. “It is about as much as is dissolved in the lava flowing out of the Earth’s mid-ocean ridges, which could be harvested to make liquid water under the right temperature and pressure conditions.”

The existence of water has implications for future lunar missions, because it could be treated and used for drinking; separated into hydrogen and oxygen for use as a rocket propellant; and the oxygen could be used for breathing. “Water is a very expensive commodity in space,” said Anand.

Oct 27, 2020

NASA’s SOFIA Discovers Water on Sunlit Surface of Moon

Posted by in categories: chemistry, physics, space

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) has confirmed, for the first time, water on the sunlit surface of the Moon. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places.

SOFIA has detected water molecules (H2O) in Clavius Crater, one of the largest craters visible from Earth, located in the Moon’s southern hemisphere. Previous observations of the Moon’s surface detected some form of hydrogen, but were unable to distinguish between water and its close chemical relative, hydroxyl (OH). Data from this location reveal water in concentrations of 100 to 412 parts per million – roughly equivalent to a 12-ounce bottle of water – trapped in a cubic meter of soil spread across the lunar surface. The results are published in the latest issue of Nature Astronomy.

“We had indications that H2O – the familiar water we know – might be present on the sunlit side of the Moon,” said Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington. “Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration.”

Oct 25, 2020

Scientists make digital breakthrough in chemistry that could revolutionize the drug industry

Posted by in categories: biotech/medical, chemistry, robotics/AI

At the Cronin Lab at the University of Glasgow chemists developed a robotic chemist called a “chemputer” that turns words into molecules.

Oct 25, 2020

New nuclear engine concept could help realize 3-month trips to Mars

Posted by in categories: chemistry, nuclear energy, space travel

Seattle-based Ultra Safe Nuclear Technologies (USNC-Tech) has developed a concept for a new Nuclear Thermal Propulsion (NTP) engine and delivered it to NASA. Claimed to be safer and more reliable than previous NTP designs and with far greater efficiency than a chemical rocket, the concept could help realize the goal of using nuclear propulsion to revolutionize deep space travel, reducing Earth-Mars travel time to just three months.

Because chemical rockets are already near their theoretical limits and electric space propulsion systems have such low thrust, rocket engineers continue to seek ways to build more efficient, more powerful engines using some variant of nuclear energy. If properly designed, such nuclear rockets could have several times the efficiency of the chemical variety. The problem is to produce a nuclear reactor that is light enough and safe enough for use outside the Earth’s atmosphere – especially if the spacecraft is carrying a crew.

According to Dr. Michael Eades, principal engineer at USNC-Tech, the new concept engine is more reliable than previous NTP designs and can produce twice the specific impulse of a chemical rocket. Specific impulse is a measure of a rocket’s efficiency.

Oct 25, 2020

Chernobyl fungus could shield astronauts from cosmic radiation

Posted by in categories: chemistry, nuclear energy, space

Will astronauts have fungi shields as protection against radiation in the future? 😃

When astronauts return to the moon or travel to Mars, how will they shield themselves against high levels of cosmic radiation? A recent experiment aboard the International Space Station suggests a surprising solution: a radiation-eating fungus, which could be used as a self-replicating shield against gamma radiation in space.

Continue reading “Chernobyl fungus could shield astronauts from cosmic radiation” »

Oct 24, 2020

Niobium — A Metal Which REPLACES GOLD!

Posted by in category: chemistry

Thanks for the niobium metal:
Do not repeat the experiments shown in this video!
So, today I will tell you about the metal that can replace gold, about niobium.
In the periodic table of chemical elements, niobium is placed in the 5th group, between vanadium and tantalum.
It got its name in the honor of Niobe, the daughter of the ancient Greek king Tantalus, and this is not a coincidence, because the properties of niobium and tantalum are very similar and at first sight they are quite hard to distinguish.
Niobium is mined from the mineral columbite, where tantalum is also present.
Because of that, until 1949 in the US, niobium was also called columbium, as in the 19th century, American scientists sometimes considered tantalum and niobium the same element and did not think about new names.
Now, when obtaining niobium from ore, it is purified from tantalum and other metals, and so pure niobium pentoxide is acquired, which is then subsequently dissolved with hydrofluoric acid, thereby obtaining complex niobium compounds.
Which are then reduced by the metallic sodium to a metallic state.
After such a process, what is obtained is a high-purity niobium which in its appearance resembles a white and a malleable metal.
If you compare its appearance with tantalum, then you can immediately see the difference in that tantalum has a more shiny surface, though it might be just the way they produce these rods.
Also niobium is about 3 times cheaper than tantalum.
Due to its high plasticity, it is easy to make a niobium foil, which is much harder to distinguish from the foil of tantalum.
Although, there is one way, as the density of niobium is almost 2 times less than that of tantalum, therefore these metals can be easily distinguished by means of scales.