jimtrue.com : school : BSC2010L : Lab 2 - Chemistry & Organic Molecules
Posted by Jim True on January 28, 2004 6:42 AM. Last Updated October 22, 2006 9:23 PM
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Lab 2 - Chemistry & Organic Molecules
Solution - forms when a solute (usually a solid) is dissolved in a solvent (usually a liquid).
Solvent - the liquid that the solute is dissolved in.
Solute - the substance being dissolved in the solute to form a solution.
Polar - Ionic molecules that have positive and negative charges in certain areas of the molecule and will dissolve easily in water or another polar substance.
Nonpolar - molecules without positive and negative charge areas that are repelled by water (hydrophobic) and will not dissolve in it, but will dissolve in a nonpolar liquid like oil.
Electrolyte - solutes that release ions when in solution; with both positive and negative electrons present, these substances can conduct an electrical charge and are thus called electrolytes.
pH - a scale of measuring how many hydrogen ions versus hydroxyl ions are in a substance. Scale runs from 0 to 14, with 0 being acidic, 14 being basic and 7 being neutral.
Base - a substance that releases hydroxyl ions (OH-) when in water.
Acid - a substance that will release hydrogen ions (H+) when in water.
Neutral - Equal amounts of hydrogen ions and hydroxyl ions; water is an excellent example of a neutral substance.
Organic - meaning containing carbon and range from small molecules to ones that are enormous in size.
Polymer - long chains of smaller molecular compounds.
Monomer - simpler, smaller molecular compounds that chain together to form polymers
Hydrolysis - adding water to a molecular compound to break it into smaller parts at the functional group.
Dehydration Synthesis - removing a water molecule where two functional groups come together to form a larger molecular compound.
Benedict's Reagent - a reagent used to detect the presence of reducing sugars (carbohydrates with an aldehyde functional group that will accept an oxygen atom from the benedict's reagent to produce an orangish color that is a positive test for reducing sugars.
Iodine (IKI) - chemical element that bonds with the coiled polysaccharides in starch molecules to produce a darker color as a positive test for starch.
Sudan IV Powder - a chemical reagent pigment that is made with ether as its solvent; lipds are nonpolar compounds that do not dissolve in water or other polar liquids but do dissolve in ether which is a positive reaction for lipids.
Biuret Reagent (Copper Sulfate + Sodium Hydroxide) - A reagent that reacts with the peptide bonds of amino acids and will produce a violet color as a positive test for proteins.
Carbohydrates - C, H, O, functional groups of hydroxyl (-OH) and Carbonyl (C=O); simple sugars being monosaccharides, double sugars as dissacharides and multiple sugars, polysaccharides. Converted quickly to energy. Oxygen bridges.
Lipids - C, H, O (N and P in phospholipids); Hydroxyl and Carboxyl in neutral fats, ester (Oxygen bridge). Three hydrocarbon chains attached to a glycerol molecule; long term energy storage.
Proteins - C, H, O, N; combine at amine and carboxyl groups (amino - acids); linkages are called peptide bonds, monomers combine to form polypeptides which combine to form proteins.
four categories of Organic biomolecules: Carbohydrates, Lipids, Proteins and Nucleic acids.
Disclaimer: These are MY notes taken from classroom lectures while I'm in the classroom. While I'm perfectly happy to share my notes with my classmates and I know I take very good notes, you should still make every effort to attend the class and TAKE YOUR OWN NOTES. I will not transcribe everything the instructor says in the classroom, and I will NEVER post pre-exam reviews. My notes will not replace the value of actually attending class and taking your own class notes.I also cannot attest to their accuracy, other than they are what was provided in the lecture; you should not reference my notes as "expert opionion" by any means, and if you notice an error or omission, please do me the favor of e-mailing me with the correction and I will re-post my notes. End of Disclaimer.