Carbohydrates

Question 1

Saccharides

Answer 1

Simplest sugar

Question 2

Monosaccharides

Answer 2

Simplest, 1 unit of sugar

Question 3

Alcohol

Answer 3

• Polar
• Hydrogen bonding
• Water soluble
• Nucleophile

Question 4

Ether

Answer 4

• Not reactive on its own
• Reactive when next to OH

Question 5

Axial

Answer 5

Axial = Alpha
Axial = 6 membered ring takes the chair position

Question 6

When are substituents on 6-membered rings more stable?

Answer 6

Substituents on 6-membered rings are usually more stable when equatorial

Question 7

What is the anomeric effect?

Answer 7

The conformation is inverted when an electronegative group is next to an oxygen in the ring.

Question 8

When you have an oxygen in a ring with an oxygen next to it, what position would it rather be?

Answer 8

Axial position

Question 9

Anomeric configuration

Answer 9

Alpha or Beta

Question 10

Absolute sterochemistry

Answer 10

D or L
Usually D in nature

Question 11

Aldehydes are…

Answer 11

Aldehyde are easy to oxidise = reducing sugars

Question 12

Glycosides

Non-sugar

Answer 12

Small non-sugar molecules attached through an anomeric position to a sugar

Question 13

Aglycon

Own

Answer 13

Small molecule part on its own

Question 14

What form are many natural products found in?

Answer 14

• Glycosides
• This is the form in which many natural products usually exist, since it allows organisms to store compounds in an inactive form

Question 15

When does glycosylation happen?

Answer 15

During metabolism of compounds in the body

Question 16

What are glycans?

Cell surface

Answer 16

Glycans are complex saccharides found on the cell surface

Question 17

What is the key role of glycans?

Cells

Answer 17

Recognition of cells

Question 18

Energy/metabolism

Oxidation, combustion

Answer 18

• Sugars are a source of energy based upon the favourable oxidation of carbon
• It provides an accessible source for the controllable equivalent of combustion

Question 19

Formula for sugars/carbohydrates

Answer 19

[CH2O]

Question 20

When do monosaccharides exist in equilibrium?

Acetal

Answer 20

Monosaccharides exist in equilibrium between different 5- and 6-membered rings because of acetal chemistry

Question 21

The anomeric effect…

Answer 21

The anomeric effect gives preference to axial hydroxyl

Question 22

What are the main functions of carbohydrates?

Answer 22

• Energy source
• Structure
• Recognition