Tag Archives: life

478 ppm

Climate Change: Plants Choke on too Much Carbon

Jun 15, 2015 03:12 AM EDT

CO2 is plant food
Earth’s current atmospheric CO2 concentration is almost 390 parts per million (ppm).  Adding another 300 ppm of CO2 to the air has been shown by literally thousands of experiments to greatly increase the growth or biomass production of nearly all plants.  This growth stimulation occurs because CO2 is one of the two raw materials (the other being water) that are required for photosynthesis.  Hence, CO2 is actually the “food” that sustains essentially all plants on the face of the earth, as well as those in the sea.  And the more CO2 they “eat” (absorb from the air or water), the bigger and better they grow. (source: Plants Need CO2)

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can be later releasedto fuel the organisms’ activities (energy transformation). This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, “light”, and σύνθεσις,synthesis, “putting together”.[1][2][3] In most cases, oxygen is also released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis maintains atmospheric oxygen levels and supplies all of the organic compounds and most of the energy necessary for life on Earth.[4]

Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed byproteins called reaction centres that contain green chlorophyll pigments. In plants, these proteins are held inside organelles calledchloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by water splitting is used in the creation of two further compounds that act as an immediate energy storage means: reduced nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), the “energy currency” of cells.

In plants, algae and cyanobacteria, long term energy storage in the form of sugars are produced by a subsequent sequence of light-independent reactions called the Calvin cycle, but some bacteria use different mechanisms, such as the reverse Krebs cycle. In the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate(RuBP).[5] Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reduced and removed to form further carbohydrates, such as glucose.

The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or hydrogen sulfide, rather than water, as sources of electrons.[6]Cyanobacteria appeared later; the excess oxygen they produced contributed to the oxygen catastrophe,[7]which rendered the evolution of complex life possible. Today, the average rate of energy capture by photosynthesis globally is approximately 130 terawatts,[8][9][10] which is about three times the current power consumption of human civilization.[11] Photosynthetic organisms also convert around 100–115 thousand million metric tonnes of carbon into biomass per year.[12][13]

Unprecedented Spike in CO2 Levels in 2015

The Last Time CO2 Was This High, Humans Didn’t Exist

What are the implications of observations above 400pm? Water supply, sea level rising, increase of precipitation intensity, food production, heat waves, health threat, biodiversity collapse, etc. IPCC report consist more than 1500 pages of science-based information about causes and implications.

Existing climate changes will go faster and more extreme & unpredictable. We know about a lot of difficult and interconnected issues like ocean acidification or new type of more intensive forest fires (has already taken place in Canada, Russia, Australia) and record existing changes there.

Featured Stories, MIT | Jun 06, 2013

400 ppm CO2? Add Other GHGs, and It’s Equivalent to 478 ppm

 

flickr-4217314587-original

The Keeling Curve record from the NOAA-operated Mauna Loa Observatory shows that the atmospheric carbon dioxide concentration hovers around 400 ppm, a level not seen in more than 3 million years when sea levels were as much as 80 feet higher than today. Virtually every media outlet reported the passage of this climate milestone, but we suspect there’s more to the story. Oceans at MIT’s Genevieve Wanucha interviewed Ron Prinn, Professor of Atmospheric Science in MIT’s Department of Earth, Atmospheric and Planetary Sciences. Prinn is the Director of MIT’s Center for Global Change Science (CGCS) and Co-Director of MIT’s Joint Program on the Science and Policy of Global Change (JPSPGC). Prinn leads the Advanced Global Atmospheric Gases Experiment (AGAGE), an international project that continually measures the rates of change of the air concentrations of 50 trace gases involved in the greenhouse effect. He also works with the Integrated Global System Model, which couples economics, climate physics and chemistry, and land and ocean ecosystems, to estimate uncertainty in climate predictions and analyze proposed climate policies.

cells

A eukaryote (/juːˈkæri.t/ or /juːˈkæriət/ yoo-karr-ee-oht or yoo-karr-ee-ət) is any organism whose cells contain a nucleus and other organelles enclosed within membranes.

Eukaryotes belong to the taxon Eukarya or Eukaryota. The defining feature that sets eukaryotic cells apart from prokaryotic cells (Bacteria and Archaea) is that they have membrane-bound organelles, especially the nucleus, which contains the genetic material, and is enclosed by the nuclear envelope.[2][3][4] The presence of a nucleus gives eukaryotes their name, which comes from the Greekεὖ (eu, “well”) and κάρυον (karyon, “nut” or “kernel”).[5] Eukaryotic cells also contain other membrane-bound organelles such asmitochondria and the Golgi apparatus. In addition, plants and algae contain chloroplasts. Eukaryotic organisms may be unicellular, ormulticellular. Only eukaryotes have many kinds of tissue made up of different cell types.

Eukaryotes can reproduce both by asexual reproduction through mitosis and sexual reproduction through meiosis. In mitosis, one cell divides to produce two genetically identical cells. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell (haploid cells). These act as sex cells (gametes – each gamete has just one complement of chromosomes, each a unique mix of the corresponding pair of parental chromosomes) resulting from genetic recombination during meiosis.

The domain Eukaryota appears to be monophyletic, and so makes up one of the three domains of life. The two other domains,Bacteria and Archaea, are prokaryotes and have none of the above features. Eukaryotes represent a tiny minority of all living things;[6]even the cells in a human’s body are outnumbered ten to one by bacteria in the gut.[7][8] However, due to their much larger size, eukaryotes’ collective worldwide biomass is estimated at about equal to that of prokaryotes.[6] Eukaryotes first developed approximately 1.6–2.1 billion years ago.

A prokaryote is a single-celled organism that lacks a membrane-bound nucleus (karyon), mitochondria, or any other membrane-bound organelle.[1] The word prokaryote comes from the Greek πρό (pro) “before” and καρυόν (karyon) “nut orkernel“.[2][3] Prokaryotes can be divided into two domains, Archaea and Bacteria. Species with nuclei and organelles are placed in the domain Eukaryota.[4]

In the prokaryotes all the intracellular water-soluble components (proteins, DNA and metabolites) are located together in thecytoplasm enclosed by the cell membrane, rather than in separate cellular compartments. Bacteria, however, do possess protein-based bacterial microcompartments, which are thought to act as primitive organelles enclosed in protein shells.[5][6]Some prokaryotes, such as cyanobacteria may form large colonies. Others, such as myxobacteria, have multicellular stages in their life cycles.[7]

Molecular studies have provided insight into the evolution and interrelationships of the three domains of biological species.[8]Eukaryotes are organisms, including humans, whose cells have a well defined membrane-bound nucleus (containing chromosomal DNA) and organelles. The division between prokaryotes and eukaryotes reflects the existence of two very different levels of cellular organization. Distinctive types of prokaryotes include extremophiles and methanogens; these are common in some extreme environments.[1]

history of the universe


Uploaded on Apr 11, 2011

Backed by stunning illustrations, David Christian narrates a complete history of the universe, from the Big Bang to the Internet, in a riveting 18 minutes. This is “Big History”: an enlightening, wide-angle look at complexity, life and humanity, set against our slim share of the cosmic timeline.

New Microbe Found in Two Distant Clean Rooms

November 06, 2013

A rare, recently discovered microbe that survives on very little to eat has been found in two places on Earth: spacecraft clean rooms in Florida and South America.

Microbiologists often do thorough surveys of bacteria and other microbes in spacecraft clean rooms. Fewer microbes live there than in almost any other environment on Earth, but the surveys are important for knowing what might hitch a ride into space. If extraterrestrial life is ever found, it would be readily checked against the census of a few hundred types of microbes detected in spacecraft clean rooms.

The work to keep clean rooms extremely clean knocks total microbe numbers way down. It also can select for microbes that withstand stresses such as drying, chemical cleaning, ultraviolet treatments and lack of nutrients. Perversely, microbes that withstand these stressors often also show elevated resistance to spacecraft sterilization methodologies such as heating and peroxide treatment.

“We want to have a better understanding of these bugs, because the capabilities that adapt them for surviving in clean rooms might also let them survive on a spacecraft,” said microbiologist Parag Vaishampayan of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the 2013 paper about the microbe. “This particular bug survives with almost no nutrients.”

This population of berry-shaped bacteria is so different from any other known bacteria, it has been classified as not only a new species, but also a new genus, the next level of classifying the diversity of life. Its discoverers named it Tersicoccus phoenicis. Tersi is from Latin for clean, like the room. Coccus, from Greek for berry, describes the bacterium’s shape. The phoenicis part is for NASA’s Phoenix Mars Lander, the spacecraft being prepared for launch in 2007 when the bacterium was first collected by test-swabbing the floor in the Florida clean room.

Some other microbes have been discovered in a spacecraft clean room and found nowhere else, but none previously had been found in two different clean rooms and nowhere else. Home grounds of the new one are about 2,500 miles (4,000 kilometers) apart, in a NASA facility at Kennedy Space Center and a European Space Agency facility in Kourou, French Guiana.

A bacterial DNA database shared by microbiologists worldwide led Vaishampayan to find the match. The South American detection had been listed on the database by a former JPL colleague, Christine Moissl-Eichinger, now with the University of Regensburg in Germany. She is first co-author of the paper published this year in the International Journal of Systematic and Evolutionary Microbiology identifying the new genus.

The same global database showed no other location where this strain of bacteria has been detected. That did not surprise Vaishampayan. He said, “We find a lot of bugs in clean rooms because we are looking so hard to find them there. The same bug might be in the soil outside the clean room but we wouldn’t necessarily identify it there because it would be hidden by the overwhelming numbers of other bugs.”

A teaspoon of typical soil would have thousands more types of microbes and billions more total microbes than an entire cleanroom. More than 99 percent of bacterial strains, as identified from DNA sequences, have never been cultivated in laboratories, a necessary step for the various types of characterization required to identify a strain as a new species.

Microbes that are tolerant of harsh conditions become more evident in clean room environments that remove the rest of the crowd.

“Tersicoccus phoenicis might be found in some natural environment with extremely low nutrient levels, such as a cave or desert,” Vaishampayan speculated. This is the case for another species of bacterium (Paenibacillus phoenicis) identified by JPL researchers and currently found in only two places on Earth: a spacecraft clean room in Florida and a bore hole more than 1.3 miles (2.1 kilometers) deep at a Colorado molybdenum mine.

Ongoing research with Tersicoccus phoenicis is aimed at understanding possible ways to control it in spacecraft clean rooms and fully sequencing its DNA. Students from California State University, Los Angeles, have participated in the research to characterize the newly discovered species.

The California Institute of Technology, Pasadena, operates JPL for NASA.

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

about origins of life

Now, research from UNC School of Medicine biochemist Charles Carter, PhD, appearing in the September 13 issue of the Journal of Biological Chemistry, offers an intriguing new view on how life began. Carter’s work is based on lab experiments during which his team recreated ancient protein enzymes that likely played a vital role in helping create life on Earth. Carter’s finding flies in the face of the widely-held theory that Ribonucleic Acid (RNA) self-replicated without the aid of simple proteins and eventually led to life as we know it.

Read more at: http://phys.org/news/2013-09-assumptions-life.html#jCp