Module 7

Question 1

Physiological roles of Carbohydrates

Answer 1

Sources of Energy, Energy storage, Structural roles, Cellular interaction, Cellular identification, Information transfer (DNA and RNA), Signalling

Question 2

Carbohydrates Empirical Formula

Answer 2

(CH2O)n n is usually 3-6

Question 3

Two classes of carbohydrates

Answer 3

Aldoses and Ketoses

Question 4

Aldose

Answer 4

Aldehyde Group

Question 5

Ketose

Answer 5

Ketone Group

Question 6

Monosaccharides

Answer 6

Multiple asymmetric carbons
Either D or L is based on the configuration of the chiral carbon most distant from the carbonyl oxygen

Question 7

L

Answer 7

OH to left

Question 8

D

Answer 8

OH to right

Question 9

Stereoisomers Formula

Answer 9

2^n n(Chiral Carbons)

Question 10

Epimers

Answer 10

Differ in one chiral Carbons

Question 11

Anomers

Answer 11

Cycilizatuin

Question 12

Cyclic Structures

Answer 12

longer carbons (5carbons and up) tend to be cyclized
Formation of these cyclized structures is the result of a reaction of an internal alcohol with either

Question 13

Aldehyde + Alcohol

Answer 13

Hemiacetal

Question 14

Ketone + Alcohol

Answer 14

Hemiketal

Question 15

6 member ring forms

Answer 15

Pyranose

Question 16

5 member ring forms

Answer 16

Furanose

Question 17

Anomeric Carbon

Answer 17

the carbon that becomes chiral as a result of cyclization is the anomeric carbon

Question 17

Anomeric Carbon

Answer 17

the carbon that becomes chiral as a result of cyclization is the anomeric carbon

Question 18

Alpha

Answer 18

Down

Question 19

Beta

Answer 19

Up

Question 20

Mutarotation

Answer 20

In solution the alpha and beta configurations interconvert by a process Called mutarotation
Mutarotation occurs through a linear intermediate
Mutarotation represents change in configuration

Question 21

Sigar Derivatives

Answer 21

Includes Nitrogen, phosphate and sulfur groups
These modifications usually indicate specialized functions

Question 22

Reducing Agents

Answer 22

Linear forms of Monosaccharides can be oxidized by mild oxidizing agents like iron and copper
Carbonyl group is oxidized to a carboxyl group

Question 23

Where is the reducing end

Answer 23

Anomeric Carbon end

Question 24

Glycosidic Bond

Answer 24

Primary Structural linkage in all polymers of monosaccharides

Question 25

O- Glycosidic Bond

Answer 25

Occurs through oxygen

Question 26

N- Glycosidic Bond

Answer 26

Occurs through nitrogen

Question 27

Disaccharides

Answer 27

The Monosaccharides have multiple hydroxyl groups means that there are many different glycosidic linkages are possible

Question 28

Glycosyltransferases

Answer 28

Higher order Carbohydrate structures are generated through the action of glycosyltranferaces

Question 29

Polysaccharides

Answer 29

Have diverse Structures and functions Biological functions include energy, storage, structural roles, cushioning and lubrication

Question 30

Homopolysaccharides

Answer 30

Are polymers containing a single type pf monosaccharide

Question 31

Heteropolysaccharides

Answer 31

Are polymers containing more than one type pf monosaccharide

Question 32

can either be

Answer 32

Branched or Unbranched

Question 33

Starch

Answer 33

A mixture of 2 molecules Found in plants and fungi

Question 34

Amylose

Answer 34

A linear polymer of glucose residues through a(1-4) Bonds. Unbranched

Question 35

Amylopectin

Answer 35

Branched. Consists of a(1-4) linked glucose residues with a(1-6) branch points every 24-30 residues

Question 36

Glycogen

Answer 36

Stored in liver and skeletal muscle of animals

Question 37

Amylopectin

Answer 37

Has one reducing end but has multiple non reducing ends

Question 38

Amylase

Answer 38

Cuts a(1-4) linkages

Question 39

Debranching Enzyme

Answer 39

Cuts a(1-6)

Question 40

Glycogen

Answer 40

Structurally identical to amylopectin has a(1-4) glucose with a(1-6) brachpoints but at every 10 residues Greater frequency of branching allows for rapid mobilization

Question 41

Cellulose

Answer 41

Primary component of plant cell walls (Fibre) Accounts for over half of the carbon of the biosphere Cellulose is a linear homopolysaccharide of glucose residues

Question 42

What does cellulose have

Answer 42

Linear arrangement of B(1-4) Glycosidic residues Cannot be cut by Amylase

Question 43

Chitin

Answer 43

Principle component of hard exoskeletons (Insects and lobsters) Linear homopolysaccharide of N- acetylglucosamine residues

Question 44

Chemical difference between chitin and cellulose

Answer 44

Replacement of hydroxyl group at C2 with acetylates amino group

Question 45

B(1-4) Linkages

Answer 45

Formation of long straight chains Fibrils are formed by parallel chains that are linked through hydrogen bonds Fibers generate a rigid supportive structure of high tensile strength

Question 46

a(1-4) linkages

Answer 46

Starch glycogen form a hollow pelican structure Hollow helix provides a compact accessible storage structure of glucose

Question 47

Blood Group Antigens

Answer 47

Sugars can be covalently linked to lipid molecules to form glycolipids A central function of glycolipids is in the blood group antigens Different patterns of sugars presented on the surface of cells by the glycolipids help the body to discriminate self from non self Differences in the blood group

Question 48

Glycoproteins

Answer 48

Proteins with covalently attached sugars Protein constituent is the largest component of weight Serve a variety of biological roles

Question 49

Proteoglycans

Answer 49

Protein component is linked to a particular type of carbohydrate called Glycosamnioglycan The Carbohydrate constiurn is largest by weight Structural and Lubricating functions

Question 50

In Glycoproteins sugars are either linked to

Answer 50

Asparagine or Threonine

Question 51

Erythropoietin

Answer 51

EPO stimulates red blood production EPO has 3 N linked and one O linked Glycosylation EPO is highly effective in the treatment of anemia EPO also exploited by endurance athletes to increase oxygen carrying capacity