Carbohydrates

Question 1

What formula do carbohydrates conform to?

Answer 1

(CH2O)n

Question 2

What is n equal to in monosaccarides?

Answer 2

3-7

Question 3

What is the difference in function between monosaccarides and polysaccarides?

Answer 3

fuel molecules for immediate consumption vs storage form

Question 4

What makes a sugar an aldose vs a ketose?

Answer 4

aldoses are sugars with an aldehyde group and ketoses are sugars with a ketone group

Question 5

Are aldoses or ketoses chiral?

Answer 5

both but ketoses have less chiral carbons than the corresponding aldose

Question 6

What are stereoisomers?

Answer 6

compounds w/identical chemical formulas but differ in chirality

Question 7

Which carbon determines whether a sugar is D or L?

Answer 7

the chiral carbon furthest from the carbonyl group

Question 8

What are enantiomers?

Answer 8

stereoisomers that are mirror images of each other

Question 9

What are diastereomers?

Answer 9

stereoisomers that are not mirror images of each other

Question 10

What are anomers?

Answer 10

stereoisomers that differ at the anomeric carbon

Question 11

Are all sugars in living systems L or D?

Answer 11

D

Question 12

Aldehydes that react with an alcohol form what?

Answer 12

hemiacetal

Question 13

Ketones that react with an alcohol form what?

Answer 13

hemiketal

Question 14

Monosaccarides that are 5 or more carbons tend to be in what form?

Answer 14

cyclic

Question 15

What are five and six membered rings called?

Answer 15

furanose and pyranose

Question 16

Oxidation of the aldehyde group on glucose yields what?

Answer 16

aldonic acid

Question 17

Oxidations of the terminal CH2OH groups yields what?

Answer 17

uronic acid

Question 18

Oxidation of the aldehyde and terminal CH2OH group yields what?

Answer 18

aldaric acid

Question 19

What creates O-glycosidic bonds?

Answer 19

reaction of anomeric hydroxyl with hydroxyl groups accompanied by the elimination of water makes these bonds

Question 20

What are some things to look for when trying to distinguish between two tpyes of disaccarides?

Answer 20

1. identify the monosaccarides
2. identify carbons involved in linkage
3. find the order of the monosaccarides
4. configuration of anomeric carbon

Question 21

What is the reducing vs non reducing end of sugars?

Answer 21

side of sugar with free anomeric carbon is reducible

Question 22

What are homopolysaccarides?

Answer 22

made up of one repeating sugar

Question 23

What are heteropolysaccarides?

Answer 23

made up of two or more types of sugar

Question 24

What are oligosaccarides?

Answer 24

polysaccaride with a small amount of monosaccaride units

Question 25

What are peptidoglycans?

Answer 25

polysaccarides that are linked to short peptides

Question 26

How do plants store glucose? What about animals?

Answer 26

starch

glycogen

Question 27

What is starch made up of?

Answer 27

two types of polymeric glucose, amylose and amylopectin

Question 28

What makes amylose form natural helices?

Answer 28

a(1->4) linkage introduces an angle that does this

Question 29

What are glycoproteins?

Answer 29

proteins with covalently bonded carb units

Question 30

What are some uses of glycoproteins?

Answer 30

antibody recognition, cell-cell recognition, blood clotting, signal transduction and host-pathogen interactions

Question 31

What are N linkages?

Answer 31

linked with asparagine

Question 32

What are O linkages?

Answer 32

can be linked with serine or threonine

Question 33

What are lectins?

Answer 33

proteins that recognize and bind to specific sugars and sugar arrangments

Question 34

What is an example of lectin?

Answer 34

influenza uses lectin (HA protein), HA protein finds sugar and uses to infect cell

cholera uses similar mechanism

Question 35

Is ribose an aldose or a ketose?

Answer 35

aldose