Carbohydrates (Monosaccharides, Disaccharides, and Polysaccharides)

Flashcards cover ring formation in common monosaccharides, forms and isomers of glucose, glycosidic linkages in disaccharides, and major polysaccharides and related concepts from the lecture notes.

In glucose, the oxygen-bridge between carbon 1 and 5 forms a _ ring.

six-membered (pyranose) ring

In fructose, the oxygen-bridge between carbon 2 and 5 forms a _ ring.

five-membered (furanose) ring

In ribose, the oxygen-bridge between carbon 1 and 4 forms a _ ring.

five-membered (furanose) ring

There are two forms of D-glucose: alpha and beta; they differ in the direction of the OH group on carbon 1: alpha has OH on the side while beta has OH on the side.

lower; upper

When many alpha-D-glucose molecules join, they form ; when many beta-D-glucose molecules join, they form .

starch; cellulose

Glucose, fructose, and galactose have the same molecular formula but differ in structure; such compounds are called isomers.

structural

Glucose and galactose are isomers due to the orientation of the OH group at carbon 4.

stereoisomers

Fructose is a sugar because its carbonyl group is on carbon 2 (a ketone) rather than at the end.

ketose

Disaccharides are formed by dehydration synthesis; the covalent linkage is a bond.

glycosidic

Lactose is made from galactose and glucose linked by a -glycosidic linkage.

1,4

Sucrose is formed from glucose and fructose linked by a -glycosidic linkage.

1,2

Maltose consists of two glucose units linked by a -glycosidic linkage.

1,4

Amylose is a component of starch that has only -glycosidic linkages and tends to form a helix.

1,4

Amylopectin contains branched structures due to -glycosidic linkages at the 1,6 positions.

1,6

Glycogen, the animal storage polysaccharide, is more than starch because it is highly branched.

branched

Cellulose is built from glucose units linked by -glycosidic bonds (beta-1,4), forming straight chains.

beta-1,4

The beta-1,4 glycosidic bonds in cellulose cannot be broken by and require the enzyme .

amylase; cellulase

Chitin is a polymer of glucose modified with an group, and is found in the exoskeletons of crabs, lobsters, and insects.

N-acetyl

Agar is derived from red algae and is used as a in foods as well as a medium for growing bacteria and fungi.

thickener

Pectin and are plant cell-wall polysaccharides mentioned in the notes.

lignin

Murein is a sugar-peptide polymer found in the cell walls of .

prokaryotes

The empirical formula of carbohydrates is C(H2O)n, where n equals the number of atoms.

carbon

The primary energy-storage molecule among the hexoses is .

glucose

High-fructose corn syrup is produced by converting glucose into .

fructose

The Haworth projection shows the sugars in their forms.

cyclic