Al Gore in his book “an inconvenient truth” begins his book with this picture and the statement “This is the first picture most of us ever saw of the Earth from space. It was taken on Christmas Eve, 1968 by one of the astronauts aboard the Apollo 8 spacecraft.” Thus, this is the way I begin …
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PART X: Was It RNA or DNA
In the last essay (Part IX: Organic Molecules), we left off with the question “Did RNA predate DNA. . .?” The problem with an RNA first scenario is that protein enzymes are required for RNA to be copied from DNA. These proteins should not have been present in an RNA world by itself. For a long time …
PART IX: (Majors) ORGANIC MOLECULES
Carbohydrates are composed entirely of atoms of carbon, hydrogen, and oxygen. All four of these classes of molecules are composed of basic units of structure. The basic unit of structure of carbohydrates is the monosaccharide or simple sugar. Simple sugars combine in a condensation reaction to produce a disaccharide or double sugar. Since one water molecule is extracted …
PART VIII: Photosynthesis and Cellular Respiration A Closer Look
For the more scientifically motivated reader I now submit an interesting corollary to the essay on photosynthesis and respiration. Most everyone knows that our bodies (all living organisms) are made up of one or more discrete units called cells and that inside these cells reside the working parts (cell organelles). I will focus on just …
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PART VII: Photosynthesis & Respiration: (An overview)
Two of the most important chemical reactions on earth are photosynthesis and respiration (cellular respiration, not just breathing). During photosynthesis plants take CO2(from the atmosphere) and water from the soil and make food (i.e. simple sugars) and convert them into more complex molecules while also releasing free oxygen. In the process energy is stored in food molecules …
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PART VI: Early Life Forms
In the previous essay I discussed some possible scenarios for the formation of the earth and some of the possible features of the earth and its atmosphere. Now I would like to look at changing conditions of the atmosphere and the earth’s surface that allowed life to be created and survive. Before life forms could survive, …
Part V: The Early Earth
In a previous essay I discussed constructive and destructive geologic forces that continue to shape and reshape the earth. Today I would like to concentrate on the planet’s birth and early (prebiotic) conditions. My purpose here is to provide facts where facts are known and discuss various theories (possible explanations). There have been and still continues to …
Part IV: Biogeochemical Cycles
Biogeochemical cycles, as the name implies, are perfect examples of the fusion of concepts from various science disciplines. Principles of biology, geology, and chemistry are combined in these cycles. Each has important implications to all living inhabitants of earth. The hydrologic cycle, also known as the water cycle, is the simplest of the cycles I will discuss …
Part III: Constructive and Destructive Forces
With the recent devastating volcano in Hawaii, I thought it would be appropriate to discuss some natural geologic forces. Earthquakes and volcanoes are, in geologic terms, called constructive forces. They can cause great destruction but here’s the point: they bring new material (lava, magma, volcanic ash, etc.) to the surface. These fertile rich materials supply the depleted …
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Part II: The Nature of Science
In the last essay we learned about some of the earliest “branches” of science that developed and why. I also discussed a loose chronological order of scientific disciplines and named a few of the more prominent early scientists. I left one very important question unanswered. What is science? Once again we find no single answer that everyone agrees upon. But …