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2: Chemistry

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    • 2.1: Introduction
      This page contains the link to a self-guided activity for reviewing basic chemistry before you continue to the Organic Chemistry section.
    • 2.2: Water
      H2O is a polar covalent molecule. The Bonds between the H atoms and the O atom arise from sharing electrons. These shared electrons form to satisfy the octet rule. However, oxygen is a “selfish” sharer. This electronegative aspect of oxygen means that the electrons of the H2O molecule preferentially associate near the oxygen atom, creating partial charges. We indicate this by placing a δ–near the O and δ+‘s near the H atoms. These partial charges make the H2O polar.
    • 2.3: Biologically Important Macromolecules
      Living things are composed of organic molecules primarily made up of the elements carbon and hydrogen. Molecules of hydrogen and carbon (referred to as hydrocarbons) have the property of being nonpolar. Yet 70- 90% of cells are composed of water (a polar compound). Polar substances mix with other polar substances. Likewise, non-polar substances interact with other non-polar compounds. Polar and non-polar compounds are immiscible (unable to mix).
    • 2.4: Chromatography
      Chromatography is a collective term for a set of analytical techniques used to separate mixtures. Chroma means color and graph means to write or draw. Paper chromatography is an analytical technique used to separate mixtures of chemicals (sometimes colored pigments) using a partitioning method. The paper in this method is called the stationary phase because it does not move and serves as a substrate or surface for the separation.
    • 2.5: pH
      We can call any compound that adds H+ ions (a free proton) into solution an acid. Along with this, we would expect that any compound that would decrease the concentration of free H+ of a solution as a base. pH is the power of H+ of a solution. We define this power as a molar concentration of H+ in solution. This concentration invariably ends up being a relatively small number (though great in absolute numbers) and is expressed as a decimal number.
    • 2.6: pH (Activity)
      This page contains a table which asks students to predict the nature and the pH of various solutions before measuring the actual pH and validating their predictions.
    • 2.7: Carbohydrates
      Carbohydrates serve 2 major functions: energy and structure. As energy, they can be simple for fast utilization or complex for storage. Simple sugars are monomers called monosaccharides. These are readily taken into cells and used immediately for energy. The most important monosaccharide is glucose (C6H12O6), since it is the preferred energy source for cells.
    • 2.8: Lipids
      Lipids are the class of macromolecules that mostly serve as long-term energy storage. Additionally, they serve as signaling molecules, water sealant, structure, and insulation. Lipids are insoluble in polar solvents such as water and are soluble in nonpolar solvents such as ether and acetone.
    • 2.9: Proteins
      Proteins provide much of the structural and functional capacity of cells. Proteins are composed of monomers called amino acids. Amino Acids are hydrocarbons that have an amino group (-NH2) and an acidic carboxyl group (-COOH). The R group represents a hydrocarbon chain with a modification that alters the properties of the amino acid. 20 universal amino acids are used to construct proteins.
    • 2.10: Nucleic Acids
      DNA and RNA are nucleic acids and make up the genetic instructions of an organism. Their monomers are called nucleotides, which are made up of individual subunits. Nucleotides consist of a 5-Carbon sugar (a pentose), a charged phosphate and a nitrogenous base (Adenine, Guanine, Thymine, Cytosine or Uracil). Each carbon of the pentose has a position designation from 1 through 5. One major difference between DNA and RNA is that DNA contains deoxyribose and RNA contains ribose.
    • 2.11: Biological Molecules (Concept)
      This page contains a Macromolecules Concept Map as well as a table which summarizes how each macromolecule can be detected.

    This page titled 2: Chemistry is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Bio-OER.

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