Lecture 7- Carbohydrate chemistry (8/19)

Question 1

To be chiral an alcove must have ? sugars and a ketone must have? sugars

Answer 1

aldose 3

ketose 4

Question 2

Glucose can cyclize to form a

Fructose can cyclize to form a

Answer 2

hemiacetal

hemiketal

Question 3

What are anomers?

Answer 3

isomers of monosaccharides that differ only in their configuration about that asymmetric carbon

Question 4

What are receding sugars?

Answer 4

sugars with a free anomeric carbon. They will reduce oxidizing agents such as peroxide, ferricyanide, and some metals.

Question 5

Redox reaction convert sugars to ?

Answer 5

Sugar acids

Aldehydes and ketones

Question 6

Is glucose a reducing sugar?

Answer 6

yes,

Question 7

Formed by mild reduction of sugars

Answer 7

sugar alcohols

Question 8

What are sialic acids ?

Answer 8

N-acetyl and N-glycolyl derivatives of neuraminic acid

Question 9

Acetals can be formed from hemiacetals as a result of ?

Answer 9

Dehydration synthesis

Question 10

Pyranose and furganose form of monosaccharides reacts with alcohols in dehydration synthesis to form ?

Answer 10

Glycosides

The new bond is called the glycosidic bond

Question 11

Is sucrose a reducing sugar?

Answer 11

No

Question 12

Starch and Glycogen are

Answer 12

Storage molecules

Question 13

Chitin and cellulose and

Answer 13

structural molecules

Question 14

The starch phosphorylase reaction claves glucose residues from amylose, producing

Answer 14

alpha -D-glucose-1-phosphate

Question 15

Starch and glycogen consists of what kind of linkages?

Answer 15

alpha 1,4

Question 16

Cellulose consists of what kind of linkages ?

Answer 16

Beta 1,4

Question 17

amylose has what linkage

Answer 17

alpha 1,4

Question 18

Cellulose strands are ? and chitin strands are ?

Answer 18

cellulose =parallel

chitins = can be parallel or antiparallel

Question 19

2 carbons on chitin are

Answer 19

N-acetyl

Question 20

One bilayer and thick peptidoglycan outer shell

Answer 20

Gram pos

Question 21

Two bilayers and thin peptidoglycan shell in between the layers

Answer 21

Gram neg

Question 22

pentaglycine bridge connects the tetra peptides

Answer 22

gram pos

Question 23

direct amide bond between tetra peptides

Answer 23

gram neg

Question 24

What unique amino acid was pointed out in the tetra peptide chain ?

Answer 24

isoglutamate

Question 25

N-linked saccharides are attached via the?

Answer 25

Amide nitirugens of asparagine residues

Question 26

O linked saccharides are attached to

Answer 26

hydroxy groups of serine , threonine or hydroxy lysine

Question 27

Function of O-linked saccharides of glycoproteins

Answer 27

Adopt an extended conformation

-these extended conformations resemble “bristle brushes”

Question 28

Bristle brush structure extends functional domains up out of the

Answer 28

glycocalyx

Question 29

Function of N-linked oligosaccharides

Answer 29

alter chem and physical properties of proteins

stabilize protein

cleavage of units from N linked targets them for degradation in the liver

Question 30

Progressive cleavage of what exposes Gal residues?

Answer 30

Sialic acid

Gal exposure increases liver binding

Question 31

proteoglycans are glycoproteins whose carbohydrates are mostly ?

Answer 31

glycosaminoglycans

Question 32

Linear chains of repeating disaccharides

Answer 32

glycosamineglycans

Question 33

Glycosaminoglycans are composed of

Answer 33

proteoglycans

Question 34

Serglycin and decorin are what type of protein?

Answer 34

soluble

Question 35

syndecan is a ? protein

Answer 35

transmembrane

Question 36

Forms the back bone structure of proteoglycans?

Answer 36

hyaluronate

Question 37

proteoglycan consists of a core protein containing ?

Answer 37

O-linked and N-linked glycosaminoglycans

Question 38

N-linked glycoproteins are of three types

Answer 38

high mannose, complex, and hybrid.

Hybrid - combines structure found in the complex and high mannose.

Question 39

The carbohydrate groups of proteoglycans are predominantly

Answer 39

glycosaminoglycans )-linked to serine residues.

Question 40

Function of proteoglycans ?

Answer 40

Modulation of cell growth process

Cushioning in joints

Question 41

Carbohydrate formula

Answer 41

(CH2O)n