For Your Information – The Basics of the Calvin Cycle

The Calvin Cycle-or also known as the C3c cycle, Calvin-Benson Bassham (CBB) cycle, dark reaction, or reductive pentose phosphate cycle- was discovered by Melvin Calvin, James Bassham, and Andrew Benson in the year of 1950. This cycle does not directly require light making it a light independent reaction of photosynthesis.

The Calvin Cycle starts out with carbon dioxide entering a plant through its leaves that contain pores called the stomata. The reactions that occur are called light-independent reactions because of their lack of use of light. Carbon atoms-which are provided by the carbon dioxide- are then incorporated into organic molecules and used to build glyceraldehyde 3-phosphate(G3P). Such process uses the help of ATP and NADPH from light reactions. Different from the light reactions, which occur in the thylakoid membrane, the cycle happens in the stroma. Then, the G3P is used as the starting point to make glucose, cellulose, starch, and other organic compounds that the plant might need

To simplify, the Calvin Cycle can be filtered down to 4 simple steps. In step one, carbon is changed. The enzyme rubisco combines a carbon dioxide molecule with the a 5-carbon sugar ribulose bisphosphate. This unstable result causes the molecule to split into 2 molecules of 3-carbon phosphoglyceric acid. The end result of this are 6 molecules of 3 carbon 3-PGA. The second step is reduction of 3-PGA molecules. Energy from the 6 molecules of ATP is used to react NADPH TO NADP+. From there, the product is six molecules of energy-rich 3-carbon sugar G3P. The third step is the releasing of a molecule of the G3P.

This leaves the remaining 5 molecules to continue the process. The final step of this cycle is to renew the RuBP. This is done through a series of chemical reactions that uses the energy of ATP to rearrange the atoms of the 5 G3P molecules, (15 carbon molecules), which forms 3 RuBP molecules (15 total carbon molecules). The end result of the last step ends with three molecules of five carbon RuBP. This is only one turn of the Calvin Cycle. This whole process will cycle again repeatedly.

To summarize, the equation of the Calvin Cycle is 3 O2+9ATP+6 NADPH+ 5H20-> glyceraldehyde-3-phosphate (G3P) + 2H+6+NADPH+9 ADP+ 8 Pi. Pi is the same as inorganic phosphate. The main reactant of the Calvin Cycle is C02, and the main product is glucose.

Knowing More About “Yuck Factor”?

Potable water has traditionally been perceived as an unlimited resource-something that would always be available in endless supply. As a result, water conservation has often been viewed as unnecessary. But California has been in a drought since 2009; it persists despite last winter’s rainy season and reservoir levels that are approaching normalcy.

Households consume 40% of California’s potable water through toilet use. Since toilets are plumbed with the same water that runs to kitchen sinks, toilet water is fine for drinking. Yet after only one use it is promptly returned to Waste Water Treatment plants. Recycled water from sinks and showers, defined as “Grey Water,” can be used for non-potable uses such as washing cars or watering plants. This recycled water, better known as water that comes from the purple pipe, is treated to a purity level only slightly lower than potable water standards.

Hopefully, after years of drought messaging the average person is aware that water conservation is something that we all need to think about.

The question is,” What stops people from recycling Grey Water to bring it up to drinking standards?” The answer is not technology-based, since reverse osmosis systems provide the technology to remove any particle, virus or contaminant in water that might be harmful to people if it is consumed.

The answer is marketing. The overriding perception is that drinking recycled water is the same as water that is flushed down the toilet. This is simply not true. Orlando, Florida and Orange County, California have both used recycled water in this way since recycled water systems became required by law in 1986.

Examples of places where water is recycled to drinking level include Singapore, where cleanliness standards are more stringent than average, and Windhoek, Naimbia, the first city in the world to use recycled water to address its drinking water requirements.

Converting previously used water to drinking standards, the true definition of “Toilet-to-Tap,” is also cheaper and creates a smaller carbon footprint when it is purified locally than when it is pumped to purification plants that may be hundreds of miles away.

In the state of California, these facts are difficult to avoid. Scientists predict that climate change will result in lower amounts of snowfall in the Sierra Nevada Mountains. The spring snowmelt from this mountain range comprises much of California’s water supply. The population growth trajectory indicates that the state’s population will be over 50 million by 2050 and, of course, all residents will require water.

An alternate source of water that has been suggested is desalinated ocean water. Desalination, however, is an energy-intensive process that currently has only niche applications. This leaves us asking: Where will our drinking water come from?

During their drought the Australians considered converting the water used recycled well enough to wash coal directly to drinking water with some added purification. Charles Fishman illustrated in his book “The Big Thirst”, Toomba Australia’s Director of Water and Waste Water services Kevin Flanagan came up with the idea based if water could be used to wash coal then why not clean it to a level where people could drink it. Once the politicians in opposition implemented a marketing campaign utilizing fear tactics they were able to affect public opinion and derail the project.

The people of Australia failed to understand the term toilet-to-tap means the water that was in your toilet is processed before being made available for drinking. Every drop of water has been recycled at some point in the earth’s history.

Water is naturally filtered by the ground, through the soil, through the zone where both water and air fill spaces between soil particles above the area where water alone fills the pore spaces. Larger particles, such as silt, leaves, and twigs are filtered out because they can’t fit through the small pore spaces. Smaller particles such as suspended clay and microorganisms become adsorbed to the soil particles. Some microorganisms are eaten by other organisms. And some dissolved chemicals such as nitrates and pesticides are consumed up by bacteria which live underground.

Our lakes and streams, provide filtering through the actions of plants and bottom-dwelling animals (like freshwater clams and mussels) which take in water, remove nutrients, and return the purified water to the environment.

Water which evaporates from the ocean due the heat provided by sunlight eventually condenses as water droplets in clouds. If the cloud grows large enough, the droplets coalesce and fall typically as rain sometimes as snow or ice. A majority of the water evaporated into the atmosphere falls as precipitation on the ocean, mostly in the tropics.

Some cities have so little clean natural water that treated sewage is reused by filtering it through the ground. Why not utilized a process used by nature for millions of years and use current technology to increase the speed and efficiency of the process?

We need to get over “the yuck factor” and take advantage of every possible resource to ensure that there is ample drinking water for everyone. I shudder to think of the ramifications if we do not.