Exam 2 - Chapter 13

Question 1

• contain several hydroxyl groups attached to a chain of three to eight carbon atoms.
• that contain an aldehyde group are classified as aldoses.
• that contain a ketone group are classified as ketoses.
• have hydroxyl groups on all carbons except the carbonyl carbon.

Answer 1

Monosaccharides

Question 2

Monosaccharides are also classified by the number of carbon atoms present.

3?
4?
5?
6?

Answer 2

triose (three C atoms)
tetrose (four C atoms)
pentose (five C atoms)
hexose (six C atoms)

Question 3

An ____ is a five-carbon saccharide with an aldehyde group.

Answer 3

aldopentose

Question 4

A ____ is a six-carbon saccharide with a ketone group.

Answer 4

ketohexose

Question 5

NAME the four major Monosaccharides listed

Answer 5

Glyceraldehyde (aldotriose)
Threose (aldotetrose)
Ribose (aldopentose)
Fructose (ketohexose)

Question 6

Objects such as hands that have nonsuperimposable mirror images are

Answer 6

chiral

Question 7

Molecules are ____ when they have the same molecular formula but different bonding arrangements.

Answer 7

structural isomers

Question 8

In _____, the atoms are bonded in the same sequence but differ in the way they are arranged in space.

Answer 8

stereoisomers

Question 9

For glyceraldehyde, the only chiral carbon is the middle carbon. In the Fischer projection, the carbonyl group, which is the most highly oxidized group, is drawn at the top.

Answer 9

True

Question 10

What are the most import monosaccharides? Draw Them

Answer 10

Glucose, galactose, and fructose are the most important monosaccharides

Question 11

They are all hexoses with the molecular formula C6H12O6 and are isomers of each other

Answer 11

D-Glucose, D-galactose, and D-fructose are the most important monosaccharides.

Question 12

• is the most common hexose.
• is found in fruits, vegetables, corn syrup, and honey.
• is also known as dextrose and blood sugar in the body.

• is a building block of the disaccharides sucrose and
lactose and of polysaccharides such as cellulose and
glycogen.

Answer 12

D-Glucose

Question 13

• is obtained from the disaccharide lactose, found in milk.

* is important in the cellular membranes of the brain and nervous system.

Answer 13

D-Galactose, an aldohexose with the formula C6H12O6,

Question 14

• is a ketohexose with the formula C6H12O6.

• is the sweetest of the carbohydrates, twice as sweet as
sucrose (table sugar).

• is obtained as one of the hydrolysis products of sucrose.

Answer 14

D-Fructose

Question 15

High-fructose corn syrup (HFCS) is a sweetener that is produced by using an enzyme to break down ____ to glucose and fructose.

Answer 15

sucrose

Question 16

Fischer Projection is ?

Answer 16

• is a two-dimensional representation of a molecule.
• places the most oxidized group at the top. • uses vertical lines for bonds that go back.
• uses horizontal lines for bonds that go forward. The intersections of vertical and horizontal lines represent a carbon atom that is usually chiral.

Question 17

In a Fischer projection, the —OH group on the

Answer 17

chiral carbon farthest from the carbonyl group

determines an L or D isomer.

Question 18

Haworth structures are produced from the reaction of a…

Answer 18

carbonyl group and a hydroxyl group in the same molecule.

Question 19

The most stable forms of pentose and hexose sugars are…

Answer 19

five- or six-atom rings.