Carbohydrates

Question 1

what is the empirical formula?

Answer 1

(CH2O)n

Question 2

what are some of the functions?

Answer 2

storage form of energy
component of cell membrane
structural components of many organisms
dietary requirements

Question 3

what is the classification of a carbohydrate with one saccharide?

Answer 3

monosaccharide

Question 4

what is the classification of a carbohydrate with two saccharide?

Answer 4

disaccharide

Question 5

what is the classification of a carbohydrate with three to ten saccharide?

Answer 5

oligosaccharides

Question 6

what is the classification of a carbohydrate with more than ten saccharide?

Answer 6

polysaccharide

Question 7

what is the name of a monosaccharide that has 3 carbon atoms?

Answer 7

trioses

Question 8

what is the name of a monosaccharide that has 4 carbon atoms?

Answer 8

tetroses

Question 9

what is the name of a monosaccharide that has 5 carbon atoms?

Answer 9

pentoses

Question 10

what is the name of a monosaccharide that has 6 carbon atoms?

Answer 10

hexoses

Question 11

monosaccharides can have structural isomers that have what in their structure?

Answer 11

ketone (C=O in structure) or aldehydes (C=O on ends of structure)

Question 12

which end are the carbons numbered from?

Answer 12

beginning at the end which has the carbonyl carbon (aldehyde or keto group)

Question 13

what are isomers?

Answer 13

Compounds that have the same chemical formula but have different structures

Question 14

what are epimers?

Answer 14

Carbohydrate isomers that differ in configuration around only one specific carbon atom

Question 15

what are enantiomers?

Answer 15

mirror images
designated D- and L- sugars
the majority of the sugars in humans are D- sugars

Question 16

what is the structure of 99% of monosaccharides?

Answer 16

in a cyclisation of monosaccharides/ ring formations

Question 17

what is the classification of a monosaccharide if the OH group faces down

Answer 17

alpha

Question 18

what is the classification of a monosaccharide if the OH group faces up?

Answer 18

beta

Question 19

what are the bonds that link sugars together?

Answer 19

glycosidic bond (catalysed by glycosyltransferases)

Question 20

how do you name a glycosidic bond?

Answer 20

If this anomeric hydroxyl is in the configuration, the linkage is an α-bond. If it is in the configuration, the linkage is a beta-bond

Question 21

when can the cyclisation of monosaccharides open the ring?

Answer 21

if the hydroxyl group on the anomeric carbon is not linked to another compound
the sugar can then act as a reducing agent and is given the term reducing sugar

Question 22

why is glucose important?

Answer 22

main sugar in the body
important source of energy
glucose is stored in large polymers which are osmotically inactive
ribose in nucleotide and nucleic acids
present in plasma membrane
form glycoproteins, glycolipids and lipids

Question 23

what is the structure of glycogen?

Answer 23

alpha 1,6 glycosidic bonds
alpha 1,4 glycosidic bonds
similar to amylopectin in starch but more branched

Question 24

what are the two forms of starch?

Answer 24

amylose and amylopectin

Question 25

what is the structural properties of cellulose?

Answer 25

chains of beta glucose joined by beta 1,4 glycosidic bonds

Question 26

what is a complex carbohydrate?

Answer 26

carbohydrates that are attached to non-carbohydrate structures like purines and pyrimidine bases, proteins and lipids

Question 27

what are N-glycoside and O-glycosides?

Answer 27

when a sugar is attached to an -NH2 group
and are joined by a N-glycosidic link
when a sugar is attached to an -OH group and are joined by a O-glycosidic link