Chapter 10: Carbohydrates

Question 1

Carbohydrates

Answer 1

Carbon based molecules that are rich in hydroxyl (C - OH)

Question 2

What is linkage of carbohydrates?

Answer 2

Glycosidic

Question 3

Polysaccharides

Answer 3

Polymers of covalently linked monosaccharides

Question 4

Monosaccharrides

Answer 4

Simplest carbohydrates
Cn(H20)n
Lowest n=3

Question 5

Function of carbohydrates

Answer 5

• major energy sources: carbohydrate oxidation
• essential structural/ protective componets
• cell to cell recognition signals

Question 6

Examples of monosaccharides

Answer 6

Dihydroxyacetone
D and L glyceraldehyde

Have 3 carbons

Question 7

D Configuration

Answer 7

OH on right of highest numbered steric carbon

Question 7

Mostly highly oxidized carbon is

Answer 7

C-1

Question 8

L Configuration

Answer 8

OH on left of highest numbered steric carbon

Question 9

In Haworth projection, D sugar CH2OH on C5

Answer 9

will be up

Question 10

In Haworth projection, L sugar CH2OH on C5

Answer 10

will be down

Question 11

Enantiomer

Answer 11

Nonsuperimposable mirror images

Question 12

How to calculate streoisomer

Answer 12

of steroisomers = 2^n
n= # of chiral centers

Question 13

Diasteroisomers

Answer 13

Isomers that are not mirror images

Question 14

Epimers

Answer 14

Differ at only ONE carbon atom

Question 15

Anomers

Answer 15

Isomers that differ at new asymmetric carbon after cyclization
Formation of a cyclic hemiacetal creates another
diastereoisomeric form

Question 16

Anomeric carbon

Answer 16

Only carbon bonded to 2 oxygen atoms

Question 17

Alpha form of anomers

Answer 17

Hydroxyl of C1 (anomeric carbon) is below the plane of ring
C5 of CH2OH and C1 of OH are opposite

Question 18

Beta form of anomers

Answer 18

Hydroxyl of C1 (anomeric carbon) is above the plane of ring
C5 of CH2OH of C1 of Oh are on same side

Question 19

Cyclization

Answer 19

OH attack C=O to form ring

Question 20

Sugar alcohols (alditols)

Answer 20

carbonyl group of sugar is reduced to an alcohol (OH) group

Question 21

Deoxy sugars

Answer 21

Reduced sugars where hydrogen atom is substitued for one of hydroxyl groups

Question 22

Reducing sugars

Answer 22

Sugars that react with oxidizing agent

Question 23

Tollens reagant test

Answer 23

Used to detect presence of reducing agent
Ag(NH3)2+ used as oxidizing agent

Question 24

Nonreducing sugars

Answer 24

Sugars that do not react with oxidizing agnet

Question 25

O glycosidic bond

Answer 25

Bond formed between anomeric carbon atom of sugar and a hydroxyl group of another molecule

Question 26

N glycosidic bond

Answer 26

Bond formed between anomeric carbon of sugar and amine

Question 27

Phosphate esters

Answer 27

Intermediates in breakdown of carbohydrates to provide energy Formed by transfer of a phosphate group from ATP to give ADP and phosphorylated sugar

Question 28

Oligosaccharides

Answer 28

Contain 2 or more monosaccharides linked by O glycosidic bonds

Question 29

Glycosyltransferases

Answer 29

Catalyze formation of glycosidic bonds

Question 30

Sucrose

Answer 30

Disaccharide Glucose + fructose

Question 31

Lactose

Answer 31

Disaccharide Glucose + galactose

Question 32

Maltose

Answer 32

Disaccharide Gluocse + Glucose

Question 33

What are storage forms of glucose?

Answer 33

Glycogen and Starch

Question 34

Glycogen

Answer 34

Most units linked by alpha 1,4 glycosidic bonds with branches formed by alpha 1,6 glycosidic bonds every 12 glucose units

Question 35

Starch

Answer 35

In plants, glucose is stored as starch 2 Forms: Amylose and Amylopectin

Question 36

Amylose

Answer 36

Fornm of starch Linear polymer of glucose units linked by alpha 1,4 glycosidic bonds

Question 37

Amylopectin

Answer 37

Form of starch Branched polymer with alpha 1,6 glycosidic bond for every 30 alpha 1,4 glycosidic bonds

Question 38

Cellulose

Answer 38

Structural componet of plants made of chains of glucose Homopolymer of glucose units linked by beta 1,4 glycosidic bonds

Question 39

Glycoproteins

Answer 39

Proteins linked to oligosaccharides

Question 40

O linked glycoproteins

Answer 40

Joined to serine or threonine in protein Golgi apparatus

Question 41

N linked glycoproteins

Answer 41

Joined to asparagine in protein E.R. and golgi apparatus