lecture ten - carbohydrates

Question 1

monosaccharides

Answer 1

basic building blocks from which all carbs are constructed
have one monomer unit

Question 2

aldose monosaccharides

Answer 2

aldehyde functional group

Question 3

ketose monosaccharides

Answer 3

ketone functional group

Question 4

oligosaccharides

Answer 4

2-10 units

Question 5

disaccharides

Answer 5

specific type of oligosaccharides that have 2 units

Question 6

polysaccharides

Answer 6

have more than 10 units, up to 1000+

Question 7

D vs L sugar

Answer 7

D glucose rotates plane-polarized light clockwise
L glucose rotates plane-polarized light counterclockwise

Question 8

isomer of the most naturally occurring carbohydrates

Answer 8

D-isomer

Question 9

configuration

Answer 9

the 3D arrangement of substituent groups around a chiral center; relates to carbs because they are either D or L isomers based on what their substituent arrangement is

Question 10

conformation

Answer 10

spatial arrangements of a molecule resulting from free rotation about the carbon-carbon single bonds

Question 11

epimer

Answer 11

monosaccharides that differ in stereochemistry at only one chiral carbon

Question 12

why do most epimers have different chemical names?

Answer 12

because they are two different chemicals with different chemical reactivities

Question 13

glucose

Answer 13

simple sugar

Question 14

fructose

Answer 14

simple sugar, found in many plants, often bonded with glucose to from sucrose

Question 15

galactose

Answer 15

simple sugar, usually found combined with other sugars

Question 16

mannose

Answer 16

important in human metabolism

Question 17

ribose

Answer 17

monosaccharide that is used in RNA

Question 18

deoxyribose

Answer 18

monosaccharide found in DNA

Question 19

N-acetyl-glucosamine

Answer 19

monosaccharide derivative of glucose; amide between glucosamine and acetic acid, important in bacterial cell wall

Question 20

N-acetyl-galactosamine

Answer 20

amino sugar derivative of galactose; in humans, it’s the terminal carb forming the antigen of blood type A

Question 21

maltose

Answer 21

disaccharide made of two glucose units, often used in fermentation, linked with 1-4 bond

Question 22

isomaltose

Answer 22

made of maltose, linked with 1-6 bond

Question 23

lactose

Answer 23

disaccharide made of glucose and galactose, often found in dairy products

Question 24

cellobiose

Answer 24

disaccharide consisting of two glucose units in beta glycosidic linkage; obtained from partial hydrolysis of cellulose

Question 25

sucrose

Answer 25

nonreducing disaccharide made of glucose and fructose

Question 26

amylose

Answer 26

D-glucose units bonded by α-1,4 glycosidic bond, make up starch

Question 27

glycogen

Answer 27

storage carb, α-1,4 and 1-6 linkages

Question 28

cellulose

Answer 28

no taste, not digestible, found in plant cell walls

Question 29

mutarotation

Answer 29

equilibration between alpha and beta anomers through the open-chain form results in alpha and beta anomers because when the compounds become cyclic, they become either alpha or beta anomers

Question 30

hemiacetals

Answer 30

alcohol and aldehyde group reacted together on the same molecule; formed through the cyclization of an aldose

Question 31

acetal

Answer 31

formed from reaction of a second alcohol molecule with a hemiacetal

Question 32

defining characteristic of a reducing sugar

Answer 32

can mutarotate through the open chain form to produce an aldehyde

Question 33

why are monosaccharides reducing sugars but methylated derivatives (at the anomeric carbon) not reducing sugars?

Answer 33

because methylated derivates become locked in acetal structure which doesn't allow them to mutarotate

Question 34

most bulky substituents are located...

Answer 34

equatorial positions

Question 35

deoxy-sugars

Answer 35

lack a hydroxyl group at one of their carbons

Question 36

sugar phosphates

Answer 36

at least one covalently bound phosphate residue

Question 37

sugar acids

Answer 37

contain at least one carboxyl group

Question 38

sugar alcohols

Answer 38

aldehyde or ketone group is replaced by additional hydroxyl group

Question 39

amino sugars

Answer 39

have amino group substitutes for one hydroxyl group

Question 40

N-acetyl derivates of glucose and galactose

Answer 40

very common components of proteoglycans and glycoproteins

Question 41

what is an N-glycosidic bond and in what compounds are these bonds found?

Answer 41

nitrogen atom of an organic base (purine or pyrimidine) is covalently linked to the anomeric group of ribose or deoxyribose these bonds are found between monosaccharides to form oligo and polysaccharides

Question 42

o-glycosidic bonds

Answer 42

link different sugars together to form di, oligo, and polysaccharides

Question 43

difference between an alpha and beta glycosidic bond

Answer 43

alpha linkage happens when the linkage from anomeric carbon radiates in the *downward* direction beta linkage occurs when the linkage from the anomeric carbon radiates in an *upward* direction

Question 44

human storage of polysaccharide

Answer 44

glycogen; contains 90% alpha 1-4 linkages and 10% alpha 1-6 linkages

Question 45

glucose

Answer 45

units in glycogen that form a spiral structure, digestible by humans

Question 46

enzymes act of what ends of glycogen

Answer 46

non-reducing ends, facilities its rapid synthesis and catabolism

Question 47

nucleotide sugar

Answer 47

something that helps synthesize carbohydrate polymers from monomers

Question 48

synthesis of carb polymers by catalysis

Answer 48

catalyzed by enzymes called glycotransferases

Question 49

synthesis of carb polymers from monomers

Answer 49

accomplished by a variety of nucleotide sugars

Question 50

cleavage of phosphoester linkages

Answer 50

drive the process in direction of polysaccharide

Question 51

major human blood types

Answer 51

A, B, O blood types are named after antigens that are found on the surface of the red blood cells, and these antigens are simple chains of sugars they are carbohydrates found on cell surfaces, attached to proteins and lipids