Discussion of carbs.

1. Organic Molecules
Biology CP - Chapter 2, Section 3

2. Classes of Organic
Molecules:
 What are the four classes of organic
molecules?
 Carbohydrates
 Lipids
 Proteins
 Nucleic Acids

3. Carbohydrates
 Sugars
 Carbo = carbon, hydrate = water;
carbohydrates have the molecular
formula (CH2O)n
 Functions:
 Store energy in chemical bonds
 Glucose is the most common
monosaccharide
 Glucose is produced by photosynthetic
autotrophs

4.  Used by living things as a main source of
energy
 Breakdown of carbohydrates supplies
immediate energy for the cell
 Complex Carbohydrates: Starches
 Simple Carbohydrates: Sugars
 1 unit of sugar = monosaccharide
 2 units = disaccharide
 more than 2 = polysaccharide
 How can you recognize a sugar by
looking at its name?
 Galactose, sucrose, lactose, fructose,
cellulose
Ends in -OSE

5. Glucose -
Monosaccharides

7. Polymerization
 Poly-mer-ization
 Poly = many
 Mer = combining
 Ization = process
 Monomers: smaller units
 Monomers can be alike or different
 Polymers: large molecule consisting
of many smaller sub-units bonded
together.

8. Polymers
 What is a polymer?
 Poly = many; mer = part. A polymer is a
large molecule consisting of many
smaller sub-units bonded together.
 What is a monomer?
 A monomer is a sub-unit of a polymer.

9. Polymer – Polysaccharide

10. Making and Breaking
Polymers
 How are covalent linkages between
monomers formed in the creation of
organic polymers?
 Condensation (making water) or
dehydration (taking away water)
synthesis reactions.
 Monomers are covalently linked to one
another through the removal of water.

11. Condensation Synthesis
(making water)

12. Hydrolysis
 What is a hydrolysis reaction?
 Polymers are broken down into
monomers.
 Hydro = water; lysis = loosening
 Water is added and the lysis of the
polymer occurs.

13. Hydrolysis (breaks water)

14. Types of Carbohydrates
 Monosaccharide – smallest unit of 3-7
carbons
 Disaccharide - two mono’s linked by
dehydration synthesis
 Polysaccharides – Many mono’s linked
by dehydration synthesis

15. Monosaccharides: Classified according to the size
of their carbon chains, varies from 3 to 7 carbons.
Triose = 3 carbons Pentose = 5 carbons Hexose = 6 carbons

16.  In aqueous solutions many
monosaccharides form rings:

17. Structure of Disaccharides
 Double sugar that consists of
2 monosaccharides

18. Examples of Disaccharides:
Lactose = glucose + galactose Sucrose = glucose + fructose

19. Polysaccharides
 Structure: Polymers of a few hundred or a few
thousand monosaccharides.
 Functions: energy storage molecules or for
structural support:

20. Cellulose is a Plant
Polysaccharide

21. Polysaccharide Examples
 Starch - plant storage from of energy,
easily hydrolyzed to glucose
 Cellulose - fiber-like structural material -
tough and insoluble - used in plant cell walls
 Glycogen - highly branched chain used by
animals to store energy in muscles and the
liver.
 Chitin - polysaccharide used as a structural
material in arthropod exoskeleton and
fungal cell walls.