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30 Cards in this Set
- Front
- Back
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What are carbohydrates?
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Molecules that have the genereal molecular formula of CnH2nOn which may also be written as (CH20)n. They usually have the ending -ose.
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Disaccharides
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Formed when 2 monosaccharides are joined together with the elimination of a water molecule, a dehydration, condensation, or synthesis reaction.
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Polysaccharides
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Formed from the combining of many monosaccharides, after dehydration. Polysaccharides are a major storage form of carbs, such as the starch in plants and glycogen in animals.
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Benedict's test
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Used to detect the presence of all monosaccharides and those disaccharides that contain a potentially free aldehyde or ketone group and are commonly called reducing sugars.
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Reducing Sugars
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Disaccharides that can donate electrons.
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What happens in a Benedict's Test?
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The blue cupric ions (Cu++) of the Benedict's Solution are reduced to red cuprous ions (Cu+) or a red copper oxide precipitate (Cu2O).
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Does a Benedict's Test require heat?
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Yes.
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What does an Iodine Test test for?
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It is used to detect the presence of the polysaccharide starch.
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What happens in an Iodine Test?
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The iodine solution (IKI), which is typically an amber-brown color, complexes with the polysaccharide, it becomes a blue-black color.
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What color is a positive Iodine test?
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Blue-black.
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What color is a positive Benedict's test?
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Red.
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How is the polysaccharide starch broken down?
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Hydrolysis -- it's done by your digestive system, using the enzyme (amylase) in your saliva and pancreatic secretions. 3M HCl and heat work, also.
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What are lipids?
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Complex organic molecules that tend to be insoluble in water because they are nonpolar.
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What are the 4 groups of lipids?
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Neutral fats, phospholipids, steroids, and other lipoid substances.
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What are phospholipids?
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Similar to neutral lipids except that they contain a phosphate group in place of one of the fatty acids chains.
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Lipoid Substances
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Include the fat soluble vitamins, A, E, and K, the eicosanoids (most of which are derived from arachidonic acid), such as prostaglandins, leukotrienes, and thromboxanes, and the lipoproteins.
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Sudan IV dye
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A simple way to demonstrate the presence of fats.
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What color is the Sudan IV dye in the first place?
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It is a dark red brown powder that is insoluble in water.
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What color is the Sudan IV dye when in a fat?
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Bright red.
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Proteins
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A group of organic molecules that are both structurally and functionally important in the human body.
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What are the building blocks of protein?
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Amino acids.
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How many naturally occurring amino acids are there?
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About 20.
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What are amino acids linked by?
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Peptide bonds.
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Ninhydrin test
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Used to detect the presence of amino acids.
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What color will amino acids turn when ninhydrin is present?
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Purple.
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Which amino acid turns yellow?
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Praline.
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What is the Biuret test?
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Used to detect the presence of polypeptides and proteins.
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What color is the Biuret solution before mixing?
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Blue.
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What color is the biuret test in the presence of polypeptides?
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Pink or purple. Solutions containing proteins will turn violet with the biuret, solutions of smaller peptides will turn pink, and solutions of amino acids alone will not show a color change and will remina blue. An exception is cysterine, which turns yellow.
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The Ninhydrin Test will not be positive until protein is broken into _____ ____
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amino acids
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