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19 Cards in this Set
- Front
- Back
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What are some reducing sugars?
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Lactose, Maltose, Glucose, Galactose, and Fructose
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What is a free anomeric carbon?
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Oxygen on C1 atom is available for redox reaction.
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What type of sugars contain a free anomeric carbon that can be oxidized?
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Reducing Sugars
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If the oxygen on the anomeric carbon (the carbonyl group) of a sugar is ___________ to any other structure, that sugar is a reducing sugar.
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If the oxygen on the anomeric carbon (the carbonyl group) of a sugar is NOT ATTACHED to any other structure, that sugar is a reducing sugar.
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T/F
A reducing sugar can react with chemical reagents and reduce the reactive component. |
True
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In a reducing sugar reaction, what becomes oxidized?
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The anomeric carbon itself becomes oxidized.
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What type of reaction is the basis of a test that was classically used by clinical laboratories to screen for diabetes (presence of excess free glucose in the blood) and other inborn errors involving the inability to metabolize other reducing sugars?
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Reducing sugars test
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Why is sucrose NOT a reducing sugar?
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Sucrose contains No free anomeric carbon.
Because the reducing groups of both glucose and fructose are involved in the glycosidic bond, sucrose is NOT a reducing sugar. |
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What are common test reagents for reducing sugars?
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Benedicts reagent (CuSO4/citrate) and Fehlings reagent (CuSO4/tartrate). They are classified as reducing sugars since they reduce the Cu2+ to Cu+ which forms as a red precipitate, copper (I) oxide.
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What are some causative factors for Glucosuria, the presence of glucose in the urine?
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1) Low Insulin Levels
2) High Blood-Sugar Levels 3) Impaired Tubular Reabsorption 4) High GFR (glomerular filtration rate) |
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What is the approximate percent composition of proteoglycan molecules?
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95% polysaccharide and 5% protein
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What is the general structure of proteoglycans?
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Proteoglycans consist of a core protein with glycosaminoglycans (GAGs) attached in a brush-like fashion.
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In proteoglycans, the linkage of GAGs to the core protein involves a specific TRISACCHARIDE composed of _____________________.
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In proteoglycans, the linkage of GAGs to the core protein involves a specific TRISACCHARIDE composed of 2 galactose residues and 1 xylose residue.
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What are the protein cores of proteoglycans rich in?
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Proteoglycan cores are rich in SERINE and THREONINE residues, which allow multiple GAG attachments.
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What are the major functions of proteoglycans?
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1) Lubricants
2) Extracellular Matrix 3) Being a Molecular "Sieve" |
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What type of structure does a glycoprotein have?
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Glycoproteins are proteins that have a carbohydrate covalently attached to them. The carbohydrate portion of most glycoproteins differes from that of proteoglycans in that it is Shorter and Branched.
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What are the functions of Glycoproteins?
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They serve as Enzymes, Hormones, Antibodies, and Structural Proteins. They are often components of cell membranes and are involved in cell-to-cell interactions.
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Where are Glycolipids (or Sphingolipids) found?
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Glycolipids are found in the cell membrane with the carbohydrate portion extending into the extracellular space.
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What are Glycolipids (or Sphingolipids) derived from?
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Glycolipids (or Sphingolipids) are derived from the lipid ceramide and this class of compounds includes cerebrosides, globosides and gangliosides.
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