CARBOHYDRATES & LIPIDS

Carbohydrates that can be oxidized by Benedict's reagent are known as non-reducing sugars.

Which of the following statements concerning carbohydrates is INCORRECT?

• Carbohydrates serve important energy and structural roles for plants and animals.

• Monosaccharides join together to form disaccharides and polysaccharides by glycosidic bonds.

• Monosaccharides are the simplest carbohydrates and are known as simple sugars.

• Humans store excess glucose for short-term energy requirements in the polysaccharide glycogen.

• Carbohydrates that can be oxidized by Benedict's reagent are known as non-reducing sugars.

monosaccharide

Which type of carbohydrate cannot be converted to simpler compounds by hydrolysis?

• starch

• cellulose

• disaccharide

• polysaccharide

• monosaccharide

aldoses

What are monosaccharides with a carbonyl group at C1 called?

• alditols

• steroisomers

• anomers

• aldoses

• ketoses

ketotetrose

What is the classification of the compound shown below?

• tetraketose

• aldotriose

• aldotetrose

• ketotetrose

• ketotriose

Which monosaccharide is an aldotriose?

farthest from the carbonyl group

To determine whether a monosaccharide is D or L, the configuration of the chiral center must be determined

• nearest to the second -OH functional group

• nearest to the carbonyl group

• nearest to the third -OH functional group

• in the center of the molecule

• farthest from the carbonyl group

L-glyceraldehyde

Which enantiomer of glyceraldehyde is represented in the following structure?

• ⍺-glyceraldehyde

• D-glyceraldehyde

• L-glyceraldehyde

• β-glyceraldehyde

• farthest from the carbonyl group

enantiomers

The Fischer projections of two monosaccharides are shown below. What is the relationship between the two monosaccharides?

• enantiomers

• cis-trans isomers

• meso isomers

• structural isomers

• diastereomers

4

How many chirality centers are present in both compounds shown above?

• 2

• 3

• 4

• 5

• 6

Which monosaccharide is an aldotriose?

The open chain of D-allose is shown below, What is the Haworth projection for ⍺-D-allose?

III only

Monosaccharides exist predominantly as cyclic hemiacetals. Cyclic hemiacetals have both an ⍺ and a β form. Which of the following monosaccharides are shown in the B form?

• IV only

• III only

• I and III

• II and IV

• All of the choices

anomers

What term properly describes the relationship between the two compounds shown?

• enantiomers

• betamers

• unrelated

• anomers

• constitutional isomers

What product forms when the compound below is treated with H2 in the presence of a Pd catalyst?

What product forms when the compound below is treated with Benedict's reagent?

glycosidic linkages

Disaccharides and polysaccharides contain monosaccharide units joined together by which of the following?

• dipole-dipole forces

• hydrogen bonding

• hemiacetal bonds

• glycosidic linkages

2

How many acetals are present in the disaccharide shown?

• 1

• 2

• 3

• 4

⍺-1→4

What type of glycosidic linkage is shown on the structure?

• β-1→6

• β-1→4

• ⍺-1→6

• ⍺-1→4

III

Which of the following structures represents the product formed when glucose is oxidized by CuSO4 in an alkaline solution to form gluconic acid?

• I

• II

• III

• IV

• V

II

Which of the following structures represents the product formed when glucose is oxidized by conc. HNO3 to form glucaric acid?

• I

• II

• III

• IV

• V

maltose

What disaccharide is composed of two glucose units joined together?

• lactose

• maltose

• galactose

• sucrose

• cellulose

cellulose

Which polysaccharide has β-glycosidic bonds?

• cellulose

• glycogen

• amylose

• amylopectin

glycogen

What is the polysaccharide form in which glucose is stored in animals?

• glycogen

• amylopectin

• glycosaminoglycans

• amylose

hyaluronate

Which carbohydrate derivative forms a gel-like matrix in joints and the vitreous humor of the eye?

• chitin

• amylose

• chondroitin

• heparin

• hyaluronate

glucose

Which monosaccharide found in the blood has its concentration regulated by the hormones insulin and glucagon?

• glucose

• galactose

• ribose

• fructose

• sucrose

three or four monosaccharides attached to a membrane protein on the surface of red blood cells

What is responsible for the different blood types in humans?

• three or four monosaccharides attached to a membrane protein on the surface of red blood cells

• three or four proteins attached to a membrane monosaccharide on the surface of red blood cells

• three or four lipids attached to a membrane polysaccharide on the surface of red blood cells

• three or four amino acids attached to a membrane monosaccharide on the surface of red blood cells

N-acetyl-D-galactosamine

Three of the four monosaccharides that determine a person's blood type are present in all blood types. Only __________ is present in Type A blood.

• N-acetyl-D-galactosamine

• D-galactose

• N-acetyl-D-glucosamine

• L-fucose

sucrose

Which is NOT a reducing sugar?

• glucose

• galactose

• aldopentose

• fructose

• sucrose

amylopectin

What type of polysaccharide is depicted in the image shown below?

• glycosaminoglycans

• cellulose

• chitin

• amylopectin

• amylose

The simplest aldose is commonly called glyceraldehyde, although its IUPAC name is 2,3-dihydroxypropanal. What is the structure of this compound?

Humans store excess glucose for short-term energy requirements in the polysaccharide cellulose.

Which statement concerning carbohydrates is INCORRECT?

• Carbohydrates that can be oxidized by Benedict's reagent are called reducing sugars.

• Humans store excess glucose for short-term energy requirements in the polysaccharide cellulose.

• Monosaccharides are the simplest carbohydrates and are known as simple sugars.

• Carbohydrates serve important energy and structural roles for both plants and animals.

It contains an ⍺-(1→5) glycosidic linkage.

Melibiose is a carbohydrate found in some plant juices. Which statement concerning melibiose is

• It contains both an acetal and a hemiacetal.

• It contains an ⍺-(1→5) glycosidic linkage.

• It is a disaccharide.

• It is composed of two different monosaccharides.

β(1→4)

What type of glycosidic linkage between glucose units is present in cellulose?

• ⍺(1→6)

• ⍺(1→4) and ⍺(1→6)

• ⍺(1→4)

• β(1→6)

• β(1→4)

glucose

What monosaccharide is found in cellulose, starch, and glycogen?

• sucrose

• maltose

• glucose

• galactose

• fructose

Amylose is a linear polysaccharide and amylopectin is a branched polysaccharide.

Amylose and amylopectin are both components of starch. How do their structures differ?

• Amylose is a polysaccharide, and amylopectin is a disaccharide.

• Amylose is a hexose, and amylopectin is a pentose.

• Amylose is a monosaccharide, and amylopectin is a polysaccharide.

• Amylose is a linear polysaccharide and amylopectin is a branched polysaccharide.

• Amylose is an aldose, and amylopectin is a ketose.