Chapter 5: Sugar as Monomers

Question 1

Carbohydrates are made up of sugars (______) that form _____

Answer 1

monosaccharides, polysaccharides

Question 2

Carbohydrates have the general structure of _____, where n varies from ___ to >___.

Answer 2

(CH2O)n, 3, 1000

Question 3

monosaccaharide

Answer 3

one sugar

Question 4

what is a ketose?

Answer 4

carbonyl group in the middle of carbon chain

Question 5

what is an aldose?

Answer 5

carbonyl group at the end of carbon chain

Question 6

carbohydrate molecules contain one _____ and multiple _____ functional groups

Answer 6

carbonyl, hydroxyl

Question 7

What is the difference between glucose and galactose?

Answer 7

• Glucose is readily used for cellular energy and structure. Galactose can only be used if enzymatically converted to glucose first.
• Because the molecular structures of glucose and galactose differ, their functions differ. Even seemingly simple changes in structure—like the spatial orientation of a single hydroxyl group—will have functional consequences.

Question 8

What are some of the things that vary among monosaccharides?

Answer 8

• Variation in carbon number
• Aldose (end) or ketose (middle) placement of the carbonyl group
• Different arrangements of hydroxyl (OH) groups in space
• Alternative ring forms

Question 9

What is a disaccharide?

Answer 9

two sugars, the result of a covalent glycosidic bond between the hydroxyl (OH) groups of two monosaccharides

Question 10

The _____ of water in a _____ reaction enables the formation of the _____ bond, a bond formed between two sugar monomers.

Answer 10

removal, dehydration, glycosidic

Question 11

The _____ of water in a _____ reaction enables the breakdown of the glycosidic bond.

Answer 11

addition, hydrolytic

Question 12

what are polysaccarhides?

Answer 12

many sugars

Question 13

_____ _____ affects the structure, function, and durability of the carbohydrates.

Answer 13

glycosidic linkages

Question 14

What is starch?

Answer 14

an energy storage polysaccharide in plants

Question 15

what is starch composed almost entirely of?

Answer 15

alpha-glucose

Question 16

what is alpha-glucose?

Answer 16

when the hydroxyl group of newly formed sugars is fixed in a position below the plane of the ring

Question 17

what is beta glucose?

Answer 17

when the hydroxyl group of newly formed sugars is fixed in a position above the plane of the ring

Question 18

Starch is comprised largely of _____-1,4-glycosidic bonds. The angle of this bond forces the polymer into a _____ orientation called _____.

Answer 18

alpha, spiral, amylose

Question 19

When alpha-1._-glycosidic bonds are present in starch, the molecule becomes branched and is called _____.

Answer 19

6, amylopectin

Question 20

What is glycogen?

Answer 20

an energy storage polysaccharide in animals

Question 21

Glycogen is stored in _____ and _____ tissue

Answer 21

liver, muscle

Question 22

Glycogen, like starch, is comprised exclusively of _____-glucose and largely of alpha-1,_-glycosidic bonds to produce the spiral-shaped polymer _____

Answer 22

alpha, 4, amylose

Question 23

Glycogen also takes the form of _____ with branched alpha-1,_-glycosidic bonds, but these branches are much more common in glycogen than in starch.

Answer 23

amylopectin, 6

Question 24

What is cellulose?

Answer 24

a structural polysaccharide in plants

Question 25

the plants ____ ____ is largely cellulose

Answer 25

cell wall

Question 26

Cellulose is a polymer made from _____-glucose monomers joined by β-1,_-glycosidic linkages. The geometry of the linkage is such that each glucose residue in the chain is _____ in relation to the adjacent residue.

Answer 26

beta, 4, flipped

Question 27

why is the flipped orientation in cellulose important?

Answer 27

(1) it generates a linear molecule, rather than the helix seen in starch; and (2) it permits multiple hydrogen bonds to form between adjacent, parallel strands of cellulose

Question 28

Interacting cellulose fibers are strong and provide _____ support for the cell and the entire plant. They are a major source of _____ _____.

Answer 28

structural, dietary fiber

Question 29

What is chitin?

Answer 29

a structural polysaccharide in fungi and animals (notably insects and crustaceans)

Question 30

The fungal cell wall is largely _____, and it helps _____ the cell wall.

Answer 30

chitin, stiffen

Question 31

the sugars of chitin are flipped by ____-1,_-glycosidic bonds, are linearly shaped, and linked to each other by hydrogen bonding, but the sugar in chitin is ________ , not glucose.

Answer 31

beta, 4, n-acetylglucosamine (NAG)

Question 32

The _____ subunits in chitin also form _____ bonds between adjacent strands to produce a stiff _____ armor.

Answer 32

NAG, hydrogen, protective

Question 33

What are peptidoglycans?

Answer 33

Peptidoglycans are a structural polysaccharide in bacteria

Question 34

the _____ cell wall is largely peptidoglycan

Answer 34

bacterial

Question 35

Peptidoglycan has a long backbone formed by _____ and _______ that alternate with each other and are linked by ___-1,_-glycosidic linkages Moreover, there are short _____ (amino acid chains) linked to the C-3 carbon of NAM acid that become _____ linked to peptides in adjacent strands.

Answer 35

NAG, N-acetylmuramic acid (NAM), beta, 4, peptides, C-3, covalently