Carbs 1

Question 1

What are carbs

Simple
And
Complex

Answer 1

Carbon based molecules that have many OH groups

Simple carbs are monosaccharides (one sugar)

Complex are polysaccharide (many sugars, covlently linked monosaccharides

Question 2

What are carbs used for

Answer 2

Energy storage
cellular recognition
Structure (ex. Exoskeleton of insects)

Question 3

What is the empirical formula of carbs

Answer 3

(Ch2O)n

N=3 trios

N= 4 tetros

Question 4

In a Fischer projection what points out in and in

Answer 4

Looked from the side of the molecule,

Horizontal bonds are out
Verticals bonds are in

Question 5

What are monosaccharides

What are the simplest monosaccharides

Answer 5

Aldehydes or ketones with two or more OH groups These are called aldoses or ketoses

The simplest have three carbons (trioses)

Question 6

What is a ketose

The simplest ketoses name

Answer 6

Ketoses if a monosaccharide with a ketone group

Called dihydroxyacetone (two OH)

Question 7

What is a aldose

What could it be named

Answer 7

A monosaccharide with and aldehyde group

Can be named D or L glyceraldehyde

Question 8

What determines the D/L of an aldose

Answer 8

If the oh on the chiral centre furthest from the Aldehyde is on the left it’s L

If on right it’s D

Question 9

Constitutional isomers

Answer 9

Same formula diff attachment of atoms

Ex. Glyceraldehyde and dihydroxyacetone

Question 10

Stereoisomer are

Answer 10

Same formula and order of attachement but different spatial arrangement

Question 11

What are enantiomers
Disasteriomer

Answer 11

Non super impossible mirror images (are mirrors and can’t be superimposed, all chiral centre changed)

Isomers that aren’t mirror images (1 or more chiral centres change)

Question 12

What is included in diasteriomers

Answer 12

Epimers or anomers

Question 13

What is an epimer

Answer 13

The chirality is different only at one of the chiral carbons (rest is the same)

Ex. D glucose and D mannose

We call them epimeric at C2

Question 14

What is an anomer

Answer 14

The diasteriomers differ at a new assymetric carbon (the anomeric carbon) formed during the closure of the ring

Alpha if the OH is down
Beta if the OH is up

Question 15

Are all diasteriomers epimers or anomers

Answer 15

No some differ at more than one chiral centre

So these ones arent

Question 16

How does ring closure of a monosaccharide aldose happen

Answer 16

The alchohol (ROH) attacked the aldehydes c=o

The c=o turns to coh and the alchohol is attached and becomes coR

Forms hemiacetal

Question 17

What is a six members ring called

What about 5

Answer 17

Pyran

Furan

Question 18

In an aldose (d glucose) which carbon attacks the aldehyde

Answer 18

The 5th one to give a six members ring (o in the ring makes 6)

Give alpha or beta d glucopyranose

Pyranose for the 6 membred ring

Question 19

PRACTICE DRAWING RING CLOSURES

Answer 19

okay

Question 20

What potion of d gluco pyranose is in the alpha and beta

Answer 20

Alpha 1/3

Beta 2/3

Question 21

What conformation of d glucopyranose is most favours

Answer 21

Chair less steric hindrance because the axial components aren’t as much on the same side of the ring

Equatorial are also more spread out

Question 22

If alpha the oh is

If beta the oh is

Answer 22

Axial

Equatorial

Question 23

In ketoses how is the ring formed

Answer 23

The alcohol reacts with the ketone to form hemiketal

Question 24

How do we name the 5 membered ring of fructose

Can the 6 members ring be made

Answer 24

Alpha or beta d fructofuranose

Yes is c6 attacks instead of c5

Question 25

For fructose (ketose) what form dominates when free in solution

What about in many fructose derivatives

Answer 25

Pyranose (6)

Furanose (5)

Question 26

Learn structures of

Answer 26

The ketose hexose d fructose

The aldoses :

Pentose D ribose

Hexose d glucose d galactose d mannose