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28 Cards in this Set
- Front
- Back
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What are 3 general characteristics of carbohydrates?
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-polyhydroxyl aldehydes or ketones
-empirical formula (CH2O)n-hydrates of carbon -more CHO than any other organic matter |
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Two ways to classify carbohydrates and examples of each.
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Classified by size (CH2O)n n = 3-9
5 = pentose 6 = hexose Classified by nature of carbonyl group Aldehyde = aldose ketone = ketose |
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Sugars have at least one ____ carbon
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asymmetric
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How are sugars oriented in Fisher projections?
What info can you see on this for Hayworth projections? |
C1 is at the top (the aldehyde or ketone), C6 or C5 is at the bottom.
Hydroxyls on left will be up, right down. Orientation of hydroxyl furthest down tells L (left)/D (right -> down) |
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What is the structure of D-Glc in a Fisher projection?
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What sugar is this?
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D-galactose
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What sugar is this?
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D-ribose
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What sugar is this?
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D-mannose
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Draw all the sugars we learned.
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What is an epimer by definition?
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isomers that differ in confirmation around one chiral carbon
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D-Glc is an epimer of
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D-Man and D-Gal
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D-Gal is an epimer of
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D-Glc
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Linear sugars form rings by making a ____ bond between the former ____ and ____
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hemiacetal
aldehyde and hydroxyl |
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How do you tell the difference between alpha and beta sugars?
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Look at anomeric carbon and what way the OH is pointing. Same as the acetyl group is Beta. Down away is alpha
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Which is more predominant alpha or beta D-glc?
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Beta 2/3
Alpha 1/3 |
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What is the interconversion of alpha to beta called?
What are you swapping between? |
mutarotation
anomers |
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Draw all the sugars as Hayworth projections.
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What is the term for a 5-membered ring sugar? 6?
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furanose
pyranose |
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Is a hexose always going to be a pyranose?
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Nope e.g. fructose is hexose that commonly forms furanose
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Onic Acids
What is it? What is the Glc derived onic acid? Draw that structure |
C1 is a carboxyl group (as opposed to aldehyde or ketone)
Gluconic acid (makes gluconate salt) |
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Uronic acid
What is it? What is the Glc derived uronic acid? Draw that structure |
Last numbered carbon is a carboxyl group (as opposed to the hydroxyl carbon)
Glucuronic acid (glucoronate) |
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Which sugar acid can form Hayworth projections?
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The uronic acids (still have aldehyde)
not the case for onic acids |
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What kind of molecules are rich in uronic acids?
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GAG glycosaminoglycans made of proteoglycans
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Sialic acids
What are they? Fact about it What is the example we learned? |
nine carbon carboxylic acid (on C1)
It's never free in the cell but always attached to proteins NANA (N-acetylneuraminic acid) |
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Amino sugars: how do they work?
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Have an amino group instead of a hydroxyl group on C2
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Two examples of amino sugars
These are both These are (?) charged in water? |
glucosamine and galactosamine
hexoamines Yes. The amino group becomes protonated. |
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What products do you get from our two amino sugar examples when the amino group gets acetylated?
What are two facts about them? |
N-acetylglucosamine GlcNAc and
N-acetylgalactosamine GalNAc GlcNAc is second most abundant sugar Both would be neutral in water |
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What disease has to do with hexosamines?
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Tay-Sach's. A sphingolipidosis disease: hexosaminidase isn't available to cleave GalNAc off of GM2 ganglioside.
Normal development for 6 months then degeneration cherry red spot. Jewish and French Canadians |
