Carbohydrates (9/12) w/Baker (unfinished)

Question 1

Monosaccharides

Answer 1

Monosaccharides are the simplest form of carbohydrates. They consist of one sugar and are usually colorless, water-soluble, crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose (dextrose), fructose, galactose, and ribose.

Question 2

Enantiomers

Answer 2

Enantiomers are chiral molecules that are mirror images of one another. Furthermore, the molecules are non-superimposable on one another. This means that the molecules cannot be placed on top of one another and give the same molecule. Chiral molecules with one or more stereocenters can be enantiomers.

Question 3

Isomers

Answer 3

each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.

Question 4

constitutional isomers

Answer 4

Constitutional isomers are compounds that have the same molecular formula and different connectivity. To determine whether two molecules are constitutional isomers, just count the number of each atom in both molecules and see how the atoms are arranged.

Question 5

stereoisomers

Answer 5

atoms are connected in the same order but differ in spatial arrangement

Question 6

diastereoisomers

Answer 6

Diastereomers (sometimes called diastereoisomers) are a type of a stereoisomer. Diastereomerism occurs when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and are not mirror images of each other.

Question 7

epimers

Answer 7

epimer refers to one of a pair of stereoisomers. The two isomers differ in configuration at only one stereogenic center.

Question 8

anomers

Answer 8

Anomers are cyclic monosaccharides or glycosides that are epimers, differing from each other in the configuration of C-1 if they are aldoses or in the configuration at C-2 if they are ketoses. The epimeric carbon in anomers are known as anomeric carbon or anomeric center.

Question 9

What are fischer projection formulas?

Answer 9

is a two-dimensional representation of a three-dimensional organic molecule by projection.

Question 10

Formation of Hemiacetal or Hemiketal

Answer 10

An aldehyde or ketone can react with an alcohol in a 1:1 ratio to yield a hemiacetal or a hemiketal respectively creating a new chiral center at the carbonyl carbon.

Question 11

Formation of acetal or ketal

Answer 11

Substitution of a second alcohol molecule produces an acetal or ketal. When the second alcohol is part of another sugar molecule the bond produced is a glycosidic bond.

Question 13

Pyranose formation

Answer 13

the pyranose ring is formed by the reaction of the hydroxyl group on carbon 5 (C-5) of a sugar with the aldehyde at carbon 1.

Question 14

Isomeric forms of fructose (furanose formation)

Answer 14

fructofuranose 5 carbon ring; fructopyranose = 6 carbon ring

Question 15

Describe a reducing sugar:

Answer 15

A reducing sugar is any sugar that is capable of acting as a reducing agent because it has a free aldehyde group or a free ketone group. All monosaccharides are reducing sugar.

There will be a test question regarding this.

Question 16

What sugar is frequently found in membranes?

Answer 16

L-fucose

Question 17

What sugar is commonly found in chitin (insect exoskeleton)?

Answer 17

N-acetyl glucosamine

Question 18

know fructose slide 22

Answer 18

know the structures of glucose, fructose and sucrose. Know the disaccharides and their structures.

Question 19

Slide 30 is a test question regarding reducing sugars

Answer 19

***all monosaccharides are reducing sugars, also some disaccharides; the only sugar that is non-reducing is sucrose because it does not have a free OH on the anomeric carbon. **Know that sucrose is **Free OH on anomeric carbon makes it a reducing sugar??? Look this up.

Question 20

Maltose

Answer 20

glucose + glucose

Question 21

Lactose

Answer 21

galactose + glucose

Question 22

Sucrose

Answer 22

fructose + glucose

Question 23

Polysaccharides

Answer 23

Know these 3: cellulose starch glycogen

Question 24

cellulose

Answer 24

***beta 1-4 glycosidic linkages: we do not have the enzymes (cellulase) to break this down, so we cannot digest cellulose.

Question 25

Starch

Answer 25

amylose alpha 1-4 (unbranched) amylopectin (branches every 30-50 residues)

Question 26

Starch

Answer 26

amylose alpha 1-4

Question 27

glycogen

Answer 27

alpha 1-4, then 10th is alpha 1-6. Look this up to clarify slide 35 in the notes

Question 28

cellulose

Answer 28

***beta 1-4 glycosidic linkages: we do not have the enzymes (cellulase) to break this down, so we cannot digest cellulose. is part of the microfibril structure of plant cell walls.

Question 29

glycogen

Answer 29

alpha 1-4, then 10th is alpha 1-6. Look this up to clarify *is a storage carbohydrate slide 35 in the notes

Question 30

Amylose

Answer 30

linear form with reducing and non reducing end slide 36

Question 31

Chitin

Answer 31

is a structural carbohydrate made of N-acetyl glucosamine units in beta 1-4 linkages

Question 32

N and O glycosylation

Answer 32

N-linked or O-linked. Do not need to know the structures, but know what these are.

Question 33

Glycoprotein

Answer 33

slide 44 blood type

Question 34

proteoglycan

Answer 34

slide 44 connective tissues ECM

Question 35

glycosamingoglycans

Answer 35

slide 46 “unusual structures, high MW, and negative charges.” Dr. Baker during lecture.

Question 36

Heparin

Answer 36

Inside mast cells, part of immune response. anticoagulant

Question 37

Carbohydrates as informational molecules:

Answer 37

The sugar code?? Participate in signaling -antibodies -toxins -virus -bacteria -receptors Refer to slide 53

Question 38

Carbohydrates in saliva

Answer 38

mucins

Question 39

Carbohydrates in saliva

Answer 39

mucins