GI- Biochem- Digestion and absorption of carbohydrates- Wells Flashcards
(89 cards)
Study this diagram

Which is the sugar molecule with the aldehyde group and which is the one with the keto group?


What are the generic names of sugars with the following number of carbons:


This is an example of what?

enantiomers (mirror images)
What are - carbohydrates are attached to non-carbohydrate structures, such as:
o Purines and pyrimidines (nitrogenous bases in nucleic acids)
o Aromatic rings, (in steroids and bilirubin)
o Proteins (in glycoproteins)
o Lipids (glycolipids)
complex carbohydrates
Carbohydrates play a role in energy and in in the cell
signaling
What are the two types of bonds by which a sugar may be attached to a non-carbohydrate group:
o –NH2 group = N-glycosidic bond (N-linked)
o –OH group = O-glycosidic bond (O-linked)

Bonds that link sugars are called bonds:
o β(1-4) glycosidic o α(1-4) glycosidic o α(1-2) glycosidic o α(1-6) glycosidic
glycosidic

The disaccharide lactose is made up of what two monosacharides and with what type of glycosidic bond?
Lactose = galactose + glucose: β(1-4)

The disaccharide sucrose is made up of what two monosacharides and with what type of glycosidic bond?
Sucrose = glucose + fructose: α(1-2)
The disaccharide maltose is made up of what two monosacharides and with what type of glycosidic bond?
Maltose = glucose + glucose: α(1-4)
What is needed to split the bond of a disaccharide sugar molecule?
H2O and glycosidase

What is a reducing sugar?
a sugar that can open and donate H
All monosaccharides, but not all disaccharides, are reducing sugars.
If the OH-group on the carbon of a cyclized sugar is not/is linked to another compound by a glycosidic bond, the ring can open.
o The sugar can act as a reducing agent (reducing sugar).
o All monosaccharides, but not all disaccharides, are reducing sugars.
anomeric
is not
Reducing sugars can react with agents (for example, the Benedict reagent)
chromogenic
The Benedict’s reagent test can detect a sugar in urine: positive result is indicative of an underlying pathology.
reducing








highly branched polymer of glucose , α 1-4 and α 1-6 linkages, major energy storage in animal (liver and muscle cells)
glycogen
What 2 forms of starch (gluclose) are found in plants and what type of glycosidic linkages do they have:
o Amylose – unbranched; α 1-4 glycosidic linkages
o Amylopectin – branched; α 1-4 and α 1-6 glycosidic linkages.
What is - unbranched glucose polymer in plants; β 1-4 glycosidic linkages (humans can’t digest).
cellulose
What type of glycosidic linkage does cellulose have?
β 1-4 glycosidic linkages












