This document discusses carbohydrates. It begins by defining carbohydrates as polyhydroxy aldehydes or ketones that yield such compounds upon hydrolysis. It then classifies carbohydrates into monosaccharides, disaccharides, and polysaccharides. Monosaccharides like glucose are the simplest units, while polysaccharides like starch are long chains of monosaccharide units. The document provides examples like sucrose and cellulose and discusses the roles of carbohydrates in biology.

1. “
CARBOHYDRATES
”
CANDICE PIENAAR
201139189

2. REFERENCES
1) http://www.slideshare.net/kleppingerb/catrbohydrates?qid=674cbdcc-2c94-43fa-8f43ffdb057f65aa&v=qf1&b=&from_search=5
2) http://www.slideshare.net/obanbrahma/carbohydrates-30770508?qid=674cbdcc-2c94-43fa8f43-ffdb057f65aa&v=qf1&b=&from_search=6
3) http://www.slideshare.net/mazz4/carbohydrates-28729095?qid=674cbdcc-2c94-43fa-8f43ffdb057f65aa&v=qf1&b=&from_search=9
4) http://www.slideshare.net/syed_ismail/carbohydrates-28872311?qid=674cbdcc-2c94-43fa8f43-ffdb057f65aa&v=qf1&b=&from_search=8
5) http://www.slideshare.net/gangadharchatterjee/carbohydrate-chemistry-27717759

4. Is an organic compound

5. σακχαρων
Greek “sakcharon” = sugar

6. LETS LEARN SOME GREEK!!!!
The name glucose comes from the Greek word
glykys (γλυκύς), meaning "sweet", plus the suffix
"-ose" which denotes a sugar
4 chiral centers give 24 = the 16 stereoisomer s
of hexose sugars. Chirality, or "handedness",
Greek, (χειρ), kheir: "hand” chiral carbons are
enantiomers
Alpha α and Beta β are letters in the Greek
alphabet

7. Carbohydrates
• Carbohydrates, or saccharides (saccharo is Greek for ―sugar)
are polyhydroxy aldehydes or ketones, or substances that yield such
compounds on hydrolysis.
• Carbohydrates include not only sugar, but also the starches that
we find in foods, such as bread, pasta, and rice.
• The term ―carbohydrate comes from the observation that when
you heat sugars, you get carbon and water (hence, hydrate of
carbon).

8. Carbohydrates and Biochemistry
•Carbohydrates are compounds of tremendous
biological importance:
–they provide energy through oxidation
–they supply carbon for the synthesis of cell
components
–they serve as a form of stored chemical energy
–they form part of the structures of some cells and
tissues
•Carbohydrates, along with lipids, proteins, nucleic
acids, and other compounds are known as
biomolecules because they are closely associated with
living organisms.

9. is the building block
of carbohydrates

10. Importance of carbohydrates:
CHIEF SOURCE OF
ENERGY

11. Types of Carbohydrates:
monosaccharide
disaccharide
polysaccharide

12. monosaccharide

13. MONOSACCHARIDES
CLASSIFICATION OF MONOSACCHARIDES
1- According to the number of carbon atoms:
.Trioses, contain 3 carbon atoms.
• Tetroses, contain 4 carbon atoms.
• Pentoses, contain 5 carbon atoms.
• Hexoses, contain 6 carbon atoms.
• Heptoses, contain 7 carbon atoms.
• Octoses. contain 8 carbon atoms.

14. Glucose (a monosaccharide)
Plants:
photosynthesis
chlorophyll
6 CO2 + 6 H2O
sunlight
(+)-glucose
C6H12O6 + 6 O2
(+)-glucose
starch or cellulose
respiration
C6H12O6 + 6 O2
6 CO2 + 6 H2O + energy

15. monosaccharide
C6H12O6
Simple sugars that consist s only one (1)
sugar molecule
Under monosaccharide:
1. Glucose
2. Fructose
3. Galactose

16. monosaccharide
1. Glucose
Blood sugar; most important sugar in the bodies of
both vertebrates and invertebrates

17. monosaccharide
2. Fructose
Corn sugar; sweetest form of sugar commonly
found in fruits

18. monosaccharide
3. Galactose
Simplest sugar found in milk

19. Animals
plant starch
(+)-glucose
(+)-glucose
glycogen
glycogen
(+)-glucose
(+)-glucose
fats or aminoacids
respiration
(+)-glucose + 6 O2
6 CO2 + 6 H2O + energy

20. 2. MONOSACCHARIDES
• Examples
20

21. 2. MONOSACCHARIDES
• Once a monosaccharide has been named as an aldose or a ketose, and the number of
carbons has been designated, there are still several different isomeric forms for each.
•
Each specific monosaccharide has a unique name.
•
A prefix (D- or L-) is added to designate which of two possible isomeric forms is being referred
to.
21

22. disaccharide

23. disaccharide
C12H22O11
Pair of monosaccharide units
Glucose + monosaccharide unit = disaccharide
Under disaccharide:
1. Sucrose
2. Lactose
3. Maltose

24. FORMING DISACCHARIDES
Glucose
CH2OH
CH2OH
CH2OH
H
C
C
O
H
H
C
C
H
OH
OH
H
C
C
OH
OH
OH
O
H
OH
H
C
C
C
H
H
C
OH
H
OH
Maltose
CH2OH
H
C
OH
C
CH2OH
O
H
OH
H
C
C
H
H
H
C
C
OH
OOH
H
C
O
H
OH
H
C
C
C
H
OH
H
H
OH
Glycosidic
Bond
OH
This is a CONDENSATION
reaction, where a water
molecule is lost.

25. disaccharide
1. Sucrose
Table sugar; glucose + fructose

26. disaccharide
2. Lactose
Milk sugar; glucose + galactose

27. disaccharide
3. Maltose
Malt sugar; glucose + glucose

28. polysaccharide

29. polysaccharide
Consists of chains of monosaccharide and
disaccharide
Under polysaccharide:
1. Starch
2. Glycogen
3. Cellulose

30. polysaccharide
1. Starch
Storage of glucose for plants

31. polysaccharide
2. Glycogen
Storage of excess sugar in animals; stored in
liver and muscles

32. polysaccharide
3. Cellulose
Structural support of plants; known as “fiber”

33. Additional info:
monomer: a molecule that may react chemically
to another molecule to form polymer; the
simplest unit; repeating unit of polymer
polymer: a compound made up of several
repeating units (monomer)
enzyme: speeds up chemical reaction

34. CLASSIFICATION:
1- Monosaccharides (simple sugars):
They can not be hydrolyzed into simpler units. E.g. glucose,
galactose,ribose
2- Oligosaccharides (oligo = few): contain from two to ten
monosaccharide units joined in glycosidic bonds. e.g.
• disaccharides (2 units) e.g. maltose and sucrose,
• trisaccharides (3 units).....etc.
3-Polysaccharides (poly = many): Also known as glycans. They are
composed of more than ten monosaccharide units e.g. starch,
glycogen, cellulose.....etc.

35. 2- According to the characteristic carbonyl group (aldehyde or ketone group):
- Aldo sugars: aldoses:
Contain aldehyde group e.g. glucose, ribose, erythrose and glyceraldehydes.
- Keto sugars: ketoses:
Contain ketone group e.g. fructose, ribulose and dihydroxy acetone.

36. GLUCOSE FORMS A RING STRUCTURE
Note: functional group is on carbon one

37. TWO TYPES OF RING
STRUCTURES FOR GLUCOSE
OH on carbon one:
BELOW the ring
ABOVE the ring

38. The existence of - and -isomers: leads to greater chemical variety
 is of importance in for example in
forming starch and cellulose

39. NOTE DIFFERENCE:
The main difference between glucose and galactose
is that glucose is much sweeter than galactose.

40. 13.4. REACTIONS--ADDITION
• Addition of an alcohol to an aldehyde:
H+
• The product is called a hemiacetal (-OH and –OR attached to the same carbon).
•
Hemiacetals are very reactive.
•
They react with an additional alcohol molecule, losing –OH and adding another –OR.
40

41. 13.4. REACTIONS--ADDITION
• The final product is an acetal (2 –OR groups attached to one carbon).
hemiacetal
acetal
41

42. 13.4. REACTIONS--ADDITION
• Ketones undergo analogous addition reactions with alcohols.
•
The initial product is a reactive hemiketal (two –R groups, one –OH, and one –OR).
•
An additional –OR group is added to the hemiketal to produce a ketal.
hemiketal
ketal
42

43. 13.4. REACTIONS--ADDITION