HEIN

What are generally defined as polyhydroxy aldehydes or ketones or substances that yield these compounds when hydrolyzed?

Carbohydrates

What are the four primary classifications of carbohydrates?

monosaccharide, disaccharide, oligosaccharide, and polysaccharide

What is a carbohydrate that cannot be hydrolyzed to simpler carbohydrate units?

monosaccharide

Which carbohydrate unit is the basic unit of cellular metabolism?

The monosaccharide

What product is yielded when a disaccharide is hydrolyzed?

two monosaccharides

What two agents can be used to catalyze the hydrolysis of a disaccharide and water?

H+ or enzymes

For what purpose are disaccharides often used by plants or animals?

to transport monosaccharides from one cell to another

What common suffix is generally found in the names of monosaccharides and disaccharides such as glucose, sucrose, and lactose?

-ose

What are water-soluble carbohydrates with a characteristically sweet taste called?

sugars

How many monosaccharide units are linked together in an oligosaccharide?

two to six

What is a macromolecular substance that can be hydrolyzed to yield many monosaccharide units?

polysaccharide

What role do polysaccharides serve particularly in plants?

important structural supports

Where do polysaccharides serve as a storage depot for monosaccharides?

cells

What are the classifications of carbohydrates based on carbon chain length?

triose, tetrose, pentose, hexose, or heptose

Into what two categories can carbohydrates be classified based on their functional groups?

aldose or ketose

What are two ways carbohydrates can be classified based on isomeric configuration?

D or L isomer and (+) or (-) isomer

What are the two structural classifications for cyclic carbohydrates?

furanose or a pyranose

What are the two configurations a carbohydrate ring can have?

alpha or beta

What are the three points of importance for carbohydrates?

effective energy-yielding nutrients, effective building materials, and important water-soluble molecules

Which hexose monosaccharides are the most important carbohydrate sources of cellular energy?

glucose, galactose, and fructose

What is the shared chemical formula for glucose, galactose, and fructose?

C6H12O6

What is the relationship between glucose, galactose, and fructose in biological systems?

they are biologically interconvertible

What is another name commonly used for glucose?

dextrose

How is glucose classified as a sugar?

aldohexose

Where is glucose found in its free state?

plant and animal tissue

How is galactose classified?

aldohexose

In which disaccharide does galactose occur alongside glucose?

lactose

What are two examples of oligo- and polysaccharides where galactose occurs?

pectin and gums

What is another name for fructose?

levulose

How is fructose classified?

ketohexose

In what three natural substances does fructose occur?

fruit juices, honey, and sucrose

What are any two monosaccharides that differ only in the configuration around a single carbon atom called?

epimers

What is an example of a pair of epimers?

D- and L-glyceraldehyde

What is an example of an aldotriose?

D-glyceraldehyde

What are two examples of aldotetroses?

D-erythrose and D-threose

What are the four aldopentoses listed in the D-family configurations?

D-ribose, D-arabinose, D-xylose, and D-lyxose

Which eight aldohexoses belong to the D-family?

D-allose, D-altrose, D-glucose, D-mannose, D-gulose, D-idose, D-galactose, and D-talose

What feature of the hydroxyl group indicates it was added in going from a triose to a tetrose to a pentose to a hexose in the D-family configurations?

it is shown in red

Which synthesis is shown to form two aldotetrose molecules from an aldotriose molecule?

Kilani-Fischer synthesis

What is the specific rotation of alpha-D-(+)-glucopyranose?

+112°

What is the specific rotation of beta-D-(+)-glucopyranose?

+18.7°

What are two cyclic isomers called when they differ only in their stereo arrangement about the carbon involved in mutarotation?

anomers

What is the name of the process by which anomers are interconverted?

Mutarotation

What is the three-dimensional representation of alpha-D-glucopyranose called?

chair form

What are cyclic structures of monosaccharides defined as?

intramolecular hemiacetals

Which ring structures are described as being especially stable for monosaccharides?

Five- or six-membered rings

What type of product is formed when a monosaccharide hemiacetal reacts with an alcohol?

acetal

What is an acetal structure called in carbohydrate terminology?

glycoside

What type of linkage unites the residues in disaccharides?

glycosidic linkage

What are the products of the hydrolysis of sucrose and water?

glucose + fructose

Which enzyme catalyzes the hydrolysis of sucrose?

sucrase

What products are yielded when lactose and water are hydrolyzed?

galactose + glucose

Which enzyme catalyzes the hydrolysis of lactose?

lactase

What products are yielded from the hydrolysis of maltose and water?

glucose + glucose

Which enzyme is used to hydrolyze maltose?

maltase

What two chemical structures does maltose contain?

an acetal structure (glycosidic linkage) and a hemiacetal structure

What value is used for the relative sweetness of fructose as a base?

100

What is the relative sweetness of Sucrose?

58

What is the relative sweetness of Glucose?

43

Which two sugars share a relative sweetness of 19?

Maltose and Galactose

What is the relative sweetness of Lactose?

9.2

Which sugar substitute has the highest relative sweetness listed at 3.5x10^4?

Sucralose

What is the relative sweetness of Saccharin (Sweet 'N Low®)?

1.7x10^4

What is the relative sweetness of Aspartame (Equal®, NutraSweet®)?

1.2x10^4

What is the relative sweetness of Acesulfame potassium (Sunette®, Sweet One®)?

1.2x10^4

To what can the aldehyde groups in monosaccharides be oxidized by mild oxidizing agents like bromine water?

monocarboxylic acids

What is used as a mild oxidizing agent for monosaccharides?

bromine water

Into what can monosaccharides be reduced?

their corresponding polyhydroxy alcohols

What are two examples of reducing agents used for monosaccharides?

H2/Pt or sodium amalgam, Na(Hg)

What happens to silver ions in a redox test for reducing sugars?

some sugars reduce silver ions to free silver

In a redox test, to what are copper (II) ions reduced?

copper (I) ions

What are sugars that can reduce silver or copper (II) ions called?

reducing sugars

Where is starch mainly found in plants?

seeds, roots, or tubers

What are the chief sources of dietary starch?

Corn, wheat potatoes, rice and cassava

What are the two main components of starch?

amylose and amylopectin

What are amylose molecules composed of?

unbranched 25-1300 alpha-D-glucose

What type of linkages join the glucose units in amylose?

alpha-1,4-glycosidic linkages

What type of linkage is shown as the branching point in amylopectin?

alpha-(1,6) Linkage

What type of linkage joins the linear segments of amylopectin?

alpha-(1,4) Linkage

What is the energy-storage carbohydrate of the animal kingdom?

Glycogen

How is glycogen formed?

by the polymerization of glucose

Where is glycogen stored?

liver and in muscle tissues

Which polysaccharide fraction of starch is glycogen structurally similar to?

amylopectin

What is the difference between the structure of glycogen and the amylopectin fraction of starch?

glycogen is more highly branched

How often do alpha-1,6-glycosidic linkages occur in glycogen?

on one of every 12-18 glucose units

What is the most abundant organic substance found in nature?

Cellulose

What is the chief structural component of plants and wood?

Cellulose

What links extended cellulose polymers to form cellulose fibers in a three-dimensional representation?

hydrogen bonding