Carbohydrates are the most abundant biomolecules on Earth and the main source of energy for living organisms. Plants make carbohydrates through photosynthesis, releasing oxygen and using carbon dioxide, water, and sunlight to produce glucose molecules. Carbohydrates come in simple and complex forms and provide energy, regulate blood glucose levels, and serve structural functions. The document then discusses the structures, functions, and examples of monosaccharides, disaccharides, oligosaccharides, and polysaccharides.

2. Carbohydrates are the most
abundant biomolecules on
earth.
It is the main source of energy
of all living organisms.

3. Plants make Carbohydrates:
Plants release oxygen as they use
water, carbon dioxide and energy
from the sun to make carbohydrates
(glucose) molecules.
Carbohydrates are based
upon the general formula
Cn(H2O)n.

4. Providing energy and regulation of blood glucose
Sparing the use of proteins for energy
Breakdown of fatty acids and preventing ketosis
Energy storage
Carbon source Recognition/Signaling

5. Aldehydes
01
Ketones
02
These are double-bonded carbon and
oxygen atoms, plus a hydrogen atom.
These are double-bonded carbon and
oxygen atoms, plus two additional
carbon atoms.
Combine together forms a polymer or chain
FUNCTIONS OF POLYMER
-long-term food storage molecules
-protective membranes for organisms and
cells
-main structural support for plants

6. SIMPLE
CARBOHYDRATES01
COMPLEX
CARBOHYDRATES02
P S
- Monosaccharides
- Disaccharides
- Oligosaccharides
- Polysaccharides
glycogen
Starches
Cellulose

7. -referred to as simple sugars
-are the smallest units that make up
any carbohydrate
-they are the building blocks
-common monosaccharides contain
from 3 to 6 carbon atoms

8. Monosaccharides
(Single Sugars)
Glucose
Formula: C₆H₁₂O₆
-”blood sugar”
-major source of energy for
cell
-simplest of the carbohydrates
-found in bread, fruits,
vegetables, and dairy
products.

9. Monosaccharides
(Single Sugars)
Fructose
Formula: -C6H12O6
-”Fruit sugar”
-sweetest of the sugars
-found in fruit, honey,
agave and most root
vegetables

10. Monosaccharides
(Single Sugars)
Galactose
Formula: -C6H12O6
Name origin: From the
Greek gala = milk,
and ose = sugar.
-”milk sugar”
-readily available in milk
and dairy products
-combined with glucose to
form lactose

11. Monosaccharides are either
aldehydes or ketones
If the sugar has an aldehyde group (the functional group with
the structure R-CHO), it is known as an aldose, and if it has a
ketone group (the functional group with the structure
RC(=O)R′), it is known as a ketose.
Depending on the number of carbons in the sugar, they also
known as trioses (three carbons), pentoses (five carbons), and
or hexoses (six carbons)
Monosaccharides are classified based on the
position of their carbonyl group and the number of
carbons in the backbone

12. Rules:
●Carbons are numbered from the top
●Most oxidized C (one with the most number
of bonds to O goes at top of (c1)
●Last carbon will always be part of a CH2OH
group (not chiral)
●Vertical lines go into the page
●Horizontal lines come out of the page
●Crosses can also be the carbons
●Stereochemistry of the last chiral carbon
determines the stereochemistry of the sugars
●If OH is to the right- D-isomer
●If OH is to the left- L- isomer
Glucose, galactose, and fructose are all hexoses. They are
structural isomers, meaning they have the same chemical
formula (C6H12O6) but a different arrangement of atoms.
Important Terms to Remember!!
Isomers= same chemical formula,different structure
Epimers=isomers that differ at only one carbon
Enantiomers= isomers that are mirror images (D and L)
Anomers= isomers that differ only at keto/aldo carbon

13. Is a common way of writing a structural formula to
represent the cyclic structure of monosaccharides
with a simple three-dimensional perspective.
Steps:
1. Number carbons, and draw in the fisher
stereochemistry (“the arms comes out to
hug you”)
2. Rotate the fisher on 90 degrees
3. Bond Rotation to C5
4. Closure of the ring

14. Glucose
(Cyclic Structure)
-OH group of carbon number one is
pointing in the opposite direction to
the carbon number six
-hydroxyl group of carbon number
one is pointing in the same direction
as carbon number six
alpha and beta carbohydrates
are also apply to other types of
carbohydrates such as galactose
as well as fructose

15. Reactions of Monosaccharides
1. OXIDATION-REDUCTION
● Complete oxidation of sugars supplies energy
●All monosaccharides are reducing
sugars(Sugars that can be oxidized )
●Reducing sugars must have free anomeric
carbon
●Free anomeric carbon=REDUCING END
●”Reducing End’ of a sugar is the end with a free
anomeric hydroxyl
2. ESTERIFICATION
Oxidation of glucose
●Esters are formed by the reaction
of alcohols (-OH) with acids.
●Most important biological esters is
the PHOSPHATE ESTER. Performs
in cells by transfer of a phosphoryl
group from ATP to a carbohydrate
hydroxyl-catalyzed by KINASES

16. “double sugar”
-sugar formed when two
monosaccharides (simple sugars)are
joined by glycosidic linkage

17. Disaccharide
Sucrose
Formula: -C12H22O11
-”table sugar or cane sugar”
-extracted from plants such
as sugar cane and sugar
beets
-It is a combination of
glucose and fructose

18. Disaccharide
Lactose
Formula: -C12H22O11
-”milk sugar”
-naturally found in milk
and dairy
-It is a combination of
glucose and galactose

19. Disaccharide
Maltose
Formula: -C12H22O11
-”malt sugar”
-It is a combination of
glucose and glucose

20. -galactose and glucose form a link and through the
“condensation” process it form lactose
- It is a B-1-4 glycosidic bond because the galactose
and glucose are in a beta configuration
-reverse reaction to break lactose requires “hydrolysis”
-glucose and fructose form a link and through the
condensation reaction form a sucrose
- bond between the glucose and fructose is a little more
complicated as it is that glucose is in an alpha
configuration and the fructose is in a beta configuration
so essentially fructose flips over sucrose
- called a-1-4 glycosidic bond because both
the glucose molecules are in an alpha
configuration
-linking of monosaccharides with one
another is called “condensation”

21. -Is a short chain of 3-10
monosaccharides unit
-found in legumes and human milk
FUNCTIONS OF
OLIGOSACCHARIDES
ON PROTEINS:
● Influence structure, folding and stability of protein
● Determine the lifetime of a protein
● Serve as markers to identify a cell type
● When glycosylated proteins are at the cell surface:
1. Can modulate cell-cell interactions
3. Can serve as antigenic determinants
2. Can modulate cell-molecule interactions

22. -Is a trisaccharide composed of
galactose, glucose and frustose
-found in beans, cabbage, brussel
sprouts, broccoli, other vegetables
and whole grains
-stachyose is a tetra-saccharide
consisting of two a-D-galactose
unit, one a-D-glucose unit, one B-
D-fructose unit.
-occurs naturally in numerous
vegetables and other plants
-mainly used as bulk sweetener

23. ●Presence or absence of the terminal carbohydrate is
genetically determined and determines the blood type
●Blood plasma contains antibodies against foreign
blood-group antigens that aggregate the foreign blood
cells
●Type A blood has antibodies that recognize B sugars
●Type B blood Contains antibodies against A sugars
●Type O blood has antibodies against both A and B
sugars (universal donor)
●Type AB blood contains neither antibody (universal
acceptor)
●Incompatible blood types cause precipitation of RBCs,
block blood flow in organs and can cause death
●Also influenced by the presence or absence of Rh factor
(blood protein)
The difference between blood type is
due to glycosylation of red blood
proteins

24. -means that the polysaccharide
contains two or more different
monosaccharides
-can be branched or unbranched
-means the polysaccharide only
contains a single type of
monosaccharides
-can be branched or unbranched
-long carbohydrate chains of monosaccharides
linked by glycosidic bonds
-serve as storage forms of monosaccharides in
both humans and plants

25. Starch
-is a storage form in plants
-found in chloroplasts in plant cells
-not water soluble
-in human diet it is found in bread, cereal and rice
-Humans and animals digest it using amylase
enzymes.
-is only made up of glucose (branched or
unbranched)
Amylose
-unbranched chain of a(1-4)D-
glucose molecules
-has 2 ends (non-reducing and
reducing end)
-non-reducing end (glucose
molecule with free-OH on c4)
-reducing end (glucose molecule
with free- OH on C4
Amylopectin
-branched chain that contains both
alpha 1 to 4 and alpha 1to 6
glycosidic bonds between glucose
-has one reducing end
-has many non-reducing ends
-branch points every 25-30 glucoses

26. Glycogen
-storage form in animals
-chains of glucose unit
-similar structure to amylopectin
-backbone linked by a-1,4 bond
-have a-1,6 branches every 8-10 residues
-has one reducing end and many non-reducing
ends

27. Cellulose
-is an important structural component of the
primary cell wall of plants
-polysaccharide consisting of a linear chain of
several hundred to many thousands of β linked
D-glucose units.
-wood, paper, and cotton are mostly made up of
cellulose