Carbohydrates Flashcards
What are the physiological roles of carbohydrates?
-Energy production in cells
-Enery storage in cells
-Structural roles in cells
-Cellular roles in cells
-Cellular identity and cell-cell interaction or signaling
-Information transfer (DNA and RNA)
What are the two major classes of carbohydrates?
-Aldoses (which have an aldehyde group)
-Ketoses (which have a ketone group)
How do you designate a sugar as D or L?
-The chiral carbon most distant from the carbonyl atom (ketone or aldehyde)
-The designation of D or L is relative to the reference molecule (OH)
How can you determine the number of stereoisomers in monosaccharides?
-Molecules with n chiral centers will have 2^n stereoisomers
-4 chiral centers will have 16 isomers
-3 chiral centers will have 8 isomers
What are epimers?
How are hemiacetal and hemiketal cyclic structures formed?
What are anomers?
What are the configurations of anomeric carbons?
What are pyran and furan ring structure?
Describe the cyclization of glucose to glucopyranose
What is mutarotation?
Draw the structure of D-Ribose
Draw the structure of D-Deoxyribose
Draw the structure of D-Glucose
Draw the structure of D-Mannose
Draw the structure of D-Galactose
Draw the structure of D-Fructose
What are the conformations of pyranoses?
Explain the cyclization of D-Fructose to Fructofuranose
Describe fructose in pyran and furan ring forms in solution
Describe the relationship between Haworth and Chair conformation respresentations
Why is glucose the most stable pyranose?
Explain galastose in Haworth and Chair representations
Explain Mannose in haworth and Chair representations
Draw the structure of B-D-Acetylglucosamine (NAG or GlcNAc)
What are reducing agents?
What is the biological formation of disaccharides?
What is the nomenclature of disaccharides?
What is the naming guide for disaccharides?
Explain the formation of Maltose disaccharide
How do you draw glycosidic bonds with haworth diagrams?
Describe the disaccharide Lactose
What are polysaccharides?
Describe energy storage in starch and glycogen
Explain energy storage in Amylose and Amylopectin (starch)
Explain energy storage in glycogen
What are alpha-linkages in polysaccharides?
What is the structure of chitin and cellulose?
Cellulose hase glucose at C2
Chitin has NAG at C2
Explain the B(1-4) in chitin and cellulose
What are glycolipids?
-Sugars can also be covalently linked to lipid molecules to form glycolipids that are found on the cell membrane
-A central function of glycolipids is in the blood group antigens
-Different patterns of sugars presented on the surface of cells by the glycolipids help the body to discriminate self from non-self
-Differences in the blood group antigens are critical for blood transfusions
What are glycoproteins?
-Extracellular proteins with covalently attached sugars
-The protein constituent is the largest component by weight
-serve a variety of biological roles
What are proteoglycans?
-Protein component is linked to a particular type of carbohydrate called glycosaminoglycan
-The carbohydrate constituent is the largest component by weight
-Often serve structural and lubricating functions in the extracellular matrix (ground substance)
-Extracellular space in tissues contains a gel-like material
-Ground substance holds cells together, provides a porous pathway for diffusion of nutrients/waste products and serves a cushioning function
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