The Marble Bar Chert under the microscope If the haematite did precipitate directly from Archean seawater, it could only have done so in the presence of oxygen, presumably produced by some early bacterial photosynthetic pioneers. In the lower part of the Marble Bar Chert, the dominant iron mineral is siderite, iron carbonate (FeCO3), which forms in the absence of oxygen and is therefore probably the result of iron-rich hydrothermal fluids reacting with anoxic and acidic Archean seawater
plecoplanet: Aeration and dissolved oxygen in the aquarium
Ammonia is converted to nitrite and nitrate in the nitrogen cycle, and these nitrifying bacteria require much more oxygen than the "ordinary" metabolism of aerobic bacteria, the ones that break down organic matter and metabolize organic carbon. The reaction for the aerobic respiration is essentially the reverse of photosynthesis, except that now there is a large release of chemical energy (from stored ATP molecules)
placental mammals One of three groups of mammals that carry their young in the mother's body for long periods during which the fetus is nourished by the placenta. During this time the atmosphere and oceans formed, life originated (or possibly "colonized" Earth), eukaryotes and simple animals evolved and by the end of the precambrian they began to accumulate hard preservable parts, the common occurrence of which marks the beginning of the Cambrian
Oxygen optodes and meters are precise and easy to use, but they are expensive.The amount of oxygen dissolved in water may be expressed as a concentration (i.e., the weight or volume of oxygen in a volume of water). The essential first step is dissolved oxygen monitoring; with this information the clam grower can evaluate lease quality and take steps to reduce the impact of dissolved oxygen
What is the difference between photosynthesis and respiration? - Homework Help - eNotes.com
In terms of ecological implications of deforestation as they relate to photosynthesis, it is not the lack of oxygen production that concerns us, because marine algae release much more oxygen per year than trees do. The main function of photosynthesis is to produce food and it captures energy for it to perform the process while respiration breakdowns food and it releases energy in the process
The Origin of Life - the rise of the Oxygen Evolving Complex
An excellent animation of the Photosystem II complex, including the light harvesting chlorophylls, the reaction center and the OEC can be downloaded at Dr. This finding, if accurate (others in the literature argue it is not biological), would be in line with the proposal that life originated at the base of ancient hydrothermal vents
Lake Access -- Dissolved Oxygen in Lakes
The development of anoxia in lakes is most pronounced in thermally stratified systems in summer and under the ice in winter when the water mass is cut-off from the atmosphere. As water moves past their gills (or other breathing apparatus), microscopic bubbles of oxygen gas in the water, called dissolved oxygen (DO), are transferred from the water to their blood
Photosynthesis definition of Photosynthesis in the Free Online Encyclopedia
Desert plants in the Crassulaceae, Cactaceae, Euphorbiaceae, and 15 other families evolved, apparently independently of C4 plants, an almost identical strategy of assimilating CO2 by which the CO2 is taken in at night when the stomata open; water loss is low because of the reduced temperatures and correspondingly higher humidities. Some parts of the chloroplast, namely the stroma, which are located between the thylakoids, contain enzymes that catalyze the dark reactions of photosynthesis, such as the conversion of carbon, nitrogen, and sulfur, as well as the biosynthesis of carbohydrates and proteins
Glossary of Terms: G
This theory suggests that landscapes go through three stages of development (youth, maturity, and old age) and argues that the rejuvenation of landscapes arises from tectonic uplift of the land. It suggests that if changes in the gas composition, temperature or oxidation state of the Earth are induced by astronomical, biological, lithological, or other perturbations, life responds to these changes by growth and metabolism
Gas-exchange experiments in 1804 showed that the gain in weight of a plant grown in a carefully weighed pot resulted from the uptake of carbon, which came entirely from absorbed carbon dioxide, and water taken up by plant roots; the balance is oxygen, released back to the atmosphere. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind: Encyclopaedia Britannica articles are written in a neutral, objective tone for a general audience
The result: When these buried oxygen-rich sediments got recycled by the Earth, and their gases got burped out again by volcanoes, the gases contained less free hydrogen than previously. However, he thinks that oxidized sediments recycled through the crust would have been the critical factor for the stability of oxygen in the atmosphere
Algae Fuel In the search for alternatives to gasoline, are algae the answer? From Pond Scum to Power In this animated primer, learn why algae and other plants make oil, and how algae oil gets converted to biodiesel. The Perfect Hunter Could social intelligence be the key to hyenas' deadly hunting skills? Sexual Cannibalism Biologist Maydianne Andrade says that the gruesome mating behavior of some spiders is a lesson in evolution
Photosynthesis
Senebier concluded (erroneously as it turned out) that in photosynthesis carbon dioxide is decomposed, with the carbon becoming incorporated in the organic matter of the plant and the oxygen being released. If, on the other hand, both the carbon dioxide and the water contribute to the oxygen released, we would expect its isotopic composition to have been some intermediate figure
Photosynthesis 1
In the light reactions, excited electrons from chlorophyll flow through a cytochrome transport system along membranes of the thylakoid disks (thylakoid membranes). When the guard cells lose water pressure on a hot day, they deflate and push together, thus closing off the stoma and reducing water loss (transpiration) through the leaf
An example pf commensalism is bromeliads (plants living on trees in rainforests) and frogs; the frogs get shelter and water from the bromeliad but the bromeliad is unaffected. C C3 PLANTA C3 plant is one that produces phosphoglyceric acid, (a molecule that has three carbon atoms) as a stable intermediary in the first step in photosynthesis (the Calvin Cycle)
Other People Are Reading Why Is Water Important to Photosynthesis? Where Does Glucose Come From in Plants? Sunlight and Photosynthesis The sun's rays are the first step in the process of photosynthesis. The chemical process that results from combining light energy, water, and carbon dioxide creates simple sugars, but the oxygen that is introduced into the equation by water is not really required
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