Module 08: Polysaccharides

Question 1

These are formed by the condensation of n molecules of monosaccharides with the removal of n-1 molecules of water

Answer 1

Polysaccharides

Question 2

How are Polysaccharides formed?

Answer 2

condensation of n molecules of monosaccharides with the removal of n-1 molecules of water.

Question 3

Why are Polysaccharides non-reducing?

Answer 3

Because condensation involves the carbonyl groups of the sugars, leaving only one free carbonyl group at the end of a big molecule

Question 4

Structurally, Polysaccharides can be what?

Answer 4

unbranched (linear) or branched molecules.

Question 5

What are the two (2) types of Polysaccharides?

Answer 5

(1) Homopolysaccharides
(2) Heteropolysaccharides

Question 6

What are some examples of Homopolysaccharides?

Answer 6

(1) Starch
(2) Glycogen
(3) Cellulose

Question 7

What are some examples of Heteropolysaccharides ?

Answer 7

(1) glycosaminoglycans,
(2) glycoproteins

Question 8

These polysaccharides contain one sugar type

Answer 8

Homopolysaccharides

Question 9

These polysaccharides contain more than
one sugar type

Answer 9

Heteropolysaccharides

Question 10

Why do polysaccharides give off a negative result in Tollen’s and Benedict’s solutions?

Answer 10

they are not sweet and have limited water solubility

Question 11

What are some functions of Homopolysaccharides?

Answer 11

(1) Storage
(2) Structural Elements

Question 12

This Homopolysaccharides is used as a storage in plants.

Answer 12

Starch

Question 13

This Homopolysaccharides is used as a storage in animals.

Answer 13

Glycogen

Question 14

This Homopolysaccharides is used as a structural element in the plants cell wall.

Answer 14

Cellulose

Question 15

This Homopolysaccharides is used as a structural element in the animal exoskeleton.

Answer 15

Chitin

Question 16

What are some functions of Heteropolysaccharides:?

Answer 16

(1) Extracellular support

Question 17

This Heteropolysaccharides functions as an extracellular support for the bacteria cell envelope

Answer 17

peptidoglycan

Question 18

This is a storage polysaccharide is a polysaccharide that is a storage form for monosaccharides and is used as an energy source in cells (plants).

Answer 18

Starch

Question 19

What is the monomeric unit of starch?

Answer 19

Glucose

Question 20

This is a straight chain polymer with a (1  4) glycosidic bonds

Answer 20

Amylose

Question 21

How much starch does amylose contain?

Answer 21

15 - 20% of the starch

Question 22

What is the molecular mass of starch?

Answer 22

50,000 (up to 1000 glucose units)

Question 23

This form of starch is a branched chain polymer.

Answer 23

Amylopectin

Question 24

When can Amylopectin contain 80% to 85% of starch?

Answer 24

a (14) glycosidic bond for straight chain and a (16) for branch

Question 25

What is the molecular mass of amylopectin?

Answer 25

300,000 (up to 100,000 glucose units) - higher than amylose

Question 26

What can humans hydrolyze?

Answer 26

Human can hydrolyze alpha linkage but not beta linkage

Question 27

This storage polysaccharides function as storage for humans and animals and contains only glucose units.

Answer 27

Glycogen

Question 28

What is the structure of glycogen

Answer 28

Branched chain polymer – a (14) glycosidic bonds in straight chains and a (16) in branches (Three times more highly branched than amylopectin in starch)

Question 29

What is the molecular mass of glycogen?

Answer 29

3,000,000 (up to 1,000,000 glucose units)

Question 30

Excess glucose in blood stored in the form of _____________.

Answer 30

glycogen

Question 31

What is the process of converting glucose to glycogen?

Answer 31

Glycogenesis

Question 32

What is the process of converting glycogen to glucose?

Answer 32

Glycogenolysis

Question 33

This is a linear Homopolysaccharides with b (1  4) glycosidic bond that serves as dietary fiber in food-- readily absorbs water and results in softer stools

Answer 33

Cellulose

Question 34

How many glucose units does cellulose contain?

Answer 34

5000 glucose units with molecular mass of 900,000

Question 35

Why can't animals and humans digest cellulose?

Answer 35

Humans don’t have enzymes that hydrolyze b (1  4) - so humans can not digest cellulose -- animals also lack these enzymes but they can digest cellulose because they have bacteria in their guts to hydrolyze cellulose

Question 36

How much cellulose is in cotton?

Answer 36

95%

Question 37

How much cellulose is in wood?

Answer 37

50%

Question 38

How much cellulose dietary fiber is desired everyday?

Answer 38

20 - 35 g

Question 39

What is the structure of chitin?

Answer 39

Linear polymer with all b (14) glycosidic linkages - it has a N-acetyl amino derivative of glucose

Question 40

What is the function of chitin?

Answer 40

Function is to give rigidity to the exoskeleton s of crabs, lobsters, shrimp, insects, and other arthropods

Question 41

This is the most abundant natural polymer on earth and accounts for over half of the carbon in the biosphere

Answer 41

Cellulose

Question 42

What comprises chitin?

Answer 42

(1) N-Acetylglucosamine

Question 43

What are the 2 components of starch

Answer 43

2 components: Amylose (linear polymer) and Amylopectin (branched polymer)

Question 44

This is the principal energy source of plants and is deposited in the chloroplasts in the form of insoluble granule

Answer 44

Starch

Question 45

What does the helical conformation of amylose in starch do?

Answer 45

Helical conformation of amylose in starch is responsible for the blue-black colored complex with iodine solution

Question 46

Why does amylose have a helical conformation?

Answer 46

Helical conformation because of the nature of the a (1 4) bond

Question 47

Explain the structure of amylopectin?

Answer 47

Up to 106 molecules of glucose residues mainly a(1 4),but has branched molecules via a(1 6) every 24-30 glucose residues.

Question 48

In terms of the digestion of starch, this randomly hydrolyses the a(1 4) bonds but can not act on a(1-->6)

Answer 48

Saliva: amylase

Question 49

In terms of the digestion of starch, this is a mixture of disaccharides (maltose) and trisaccharides (maltotriose), and oligosaccharides (dextrins) containing the a(1,6) branches (hydrolyzed by a-glucosidases and a debranching enzyme).

Answer 49

Small Intestine: pancreatic amylase

Question 50

This is the storage polysaccharide of animals (skeletal muscle and liver). It structurally it resembles Amylopectin, but is more branched

Answer 50

Glycogen

Question 51

How is glycogen degraded?

Answer 51

1. glycogen phosphorylase (cleaves the  (1  4) bonds) 2. glycogen debranching enzyme (cleaves the  (1 6) bonds).

Question 52

These are polysaccharides with a repeating disaccharide unit containing an amino sugar and a sugar with a negative charge due to a sulfate or a carboxyl group.

Answer 52

Acidic polysaccharides

Question 53

These are present in connective tissue associated with joints, cartilage, synovial fluids in animals and humans

Answer 53

Structural polysaccharide

Question 54

What is the primary function of structural polysaccharide?

Answer 54

(1) Primary function is lubrication necessary for joint movement (3) These are Heteropolysaccharides - have more than one type of monosaccharide monomers is present.

Question 55

This is highly viscous and serve as lubricants in the fluid of joints and part vitreous humor of the eye.

Answer 55

Hyaluronic acid

Question 56

How is Hyaluronic acid composed?

Answer 56

Alternating residues of N-acetyl-b-D-glucosamine and D-glucuronic acid.

Question 57

This is an anticoagulant-prevents blood clots.

Answer 57

Heparin

Question 58

How many disaccharide residues per chain comprises heparin?

Answer 58

15–90 disaccharide residues per chain.

Question 59

This is a lipid molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it.

Answer 59

glycolipid

Question 60

This is a protein molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it.

Answer 60

glycoprotein

Question 61

Foods high in carbs content constitute over _____of the diet of most people of the world

Answer 61

50%

Question 62

a balanced dietary food should contain about _____of carbohydrate:

Answer 62

60%

Question 63

These are dietary monosaccharides or disaccharides - sweet to taste commonly referred to as sugars - 20 % of the energy in the US die

Answer 63

Simple carbohydrates

Question 64

These are Dietary polysaccharides constituted of starch and cellulose and is normally not sweet to taste

Answer 64

Complex carbohydrates

Question 65

How is glycemic effect classified?

Answer 65

how quickly carbs are digested how high blood glucose rise how quickly blood glucose levels return to normal

Question 66

This has been developed for rating foods

Answer 66

Glycemic index (GI)

Question 67

These are Polysaccharide that make up the bacterial cell walls.

Answer 67

Peptidoglycans

Question 68

What is the structure of Peptidoglycans?

Answer 68

It is composed of amino sugars forming the glycan strand and cross-linked polypeptides and alternating amino sugars are NAG and NAM

Question 69

What is the function of Peptidoglycans?

Answer 69

The peptidoglycan layer is responsible for reacting with crystal violet with gram (+) bacteria

Question 70

This is a linear chain of alternating N-acetyl-glucosamine (NAG) and N-acetylmuramic acid (NAM).

Answer 70

Murein

Question 71

What does each N-acetylmuramic acid (NAM).bear in peptidoglycans?

Answer 71

Each NAM bears a tetrapeptide composed of alternating L and D amino acids.

Question 72

These are cross linked into sheets by bonds between the tetrapeptides.

Answer 72

Adjacent glycan chains

Question 73

These are polymers of ribose or glycerol

Answer 73

Teichonic acids

Question 74

the gram negative cell wall is composed of what?

Answer 74

Bilayer with usual phospholipids in the inner leaflet but with LPS on the outer leaflet, Lipid A, core polysaccharide, O antigen polysaccharide side chains.

Question 75

These are toxic antigenic determinants in the the gram negative cell wall

Answer 75

Lipopolysaccharide (LPS)

Question 76

A group of important membrane bound oligosaccharides found on the surface of RBCs

Answer 76

Blood Group Antigens or ABO Antigens

Question 77

What happens when individuals are infused with blood with a different antigen?

Answer 77

The oligosaccharide chain elicit an Ab response causing agglutination of the blood