Ch 4: Carbon and Molecular Diversity of Life Flashcards
How does carbon move through the biosphere? What molecules of life contain carbon?
All living things contain carbon atoms, and carbon can get transferred around the environment with the carbon cycle. Carbon can be moved from the atmosphere to the biosphere by plants through photosynthesis, and decomposers can return carbon from the dead organisms back into the atmosphere as carbon dioxide. Carbon dioxide can be released into the atmosphere or soil through respiration, excretion, and decomposition. Carbohydrates, proteins, lipids, and nucleic acids all contain carbon.
Explain HOW the overall percentage of the major elements (C, H, O, N, S, & P) can be quite uniform from organism to organism, BUT that different species and different individuals within a species can be distinguished by the molecules that these elements form.
Carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus make up CHONSP, the major elements, and can be pretty uniform from organism to organism due to our common evolutionary origins of life. However, different individuals/species can be distinguished due to carbon’s ability to form 4 bonds, which allows it to bond with several elements and produce a variety of organisms.
Vitalism is the idea that living organisms are fundamentally different from non-living things. The vitalist hypothesis was that only living organisms could make the components of living things. Stanley Miller, helped to “crumble” vitalism. Explain what he did and what he found. What did this suggest about the “origins of life?”
Stanley Miller set up a close system to simulate conditions of early Earth to investigate whether organic molecules could form. Miller identified a variety of organic molecules varying in complexity, such as hydrogen cyanide, amino acids, and hydrocarbons. The experiments disproved the hypothesis of vitalism and concluded that origins of life, or organic molecules, may have been formed abiotically on primeval Earth.
Number of electrons in each shell of a carbon atom, and the number of protons and neutrons. How many bonds can carbon form?
There are four electrons in the valence shell, meaning there needs to be 4 more electrons to fill the shell, so a carbon atom can form 4 covalent bonds.
What is a “carbon skeleton”? How can they vary from each other? How does this make carbon so versatile?
A carbon skeleton is the way carbon atoms are chained to other elements in a molecule, and form the base of most organic materials. Carbon skeletons have various lengths, can be branched, straight, and arranged in a variety of forms. The variety in carbon skeletons and its bonds with different elements produce different molecules, which makes carbon versatile.
What are hydrocarbons? Where are they prevalent in organisms? List two properties of hydrocarbons.
Hydrocarbons are organic molecules containing only carbon and hydrogen. Hydrocarbons are nonpolar, and undergo reactions that release a large amount of energy, e.g. gasoline and the tails of fats that serve as stored fuel for organisms.
