1. Carbohydrates

2. Objectives
Distinguish among proteins, carbohydrates, lipids and nucleic acids. (SPI )
Identify or describe the skeleton structure of carbohydrates.
Identify the most metabolically important carbohydrate.
Identify and describe the carbohydrate form used to store excess energy resources in plants, animals and fungi.
Identify the major carbohydrate polymers and their respective biological functions.
Explain the biochemical processes that form polymers of simple sugars.
Identify positive tests for carbohydrates, lipids and proteins (SPI )
Describe the biochemical test to detect simple sugars and starch

3. Mono-, di-, and poly- saccharides (Sugars)
CARBOHYDRATES
Mono-, di-, and poly- saccharides (Sugars)

4. Carbohydrate Skeleton Structure
Have the general formula:
(CH2O)n
“Carbonated Water”

5. Monosaccharides
(Single Sugars)
Simple sugars with a backbone of three to seven carbon atoms.
Best known monosaccharides sugars have six carbons (hexoses).
Glucose
Fructose
Galactose

6. Dissacharides (Double Sugars)
Two monosaccharide (single sugars) joined by dehydration synthesis.
-Lactose Galactose + Glucose
Found in milk.
-Maltose Glucose + Glucose
Forms in human digestive tract during starch digestion.
-Sucrose Glucose + Fructose
Transported within plants.

8. Polysaccharides
Chains of glucose molecules or modified glucose molecules.

9. Polysaccharides (carbohydrates) Used For Energy Storage
Starch.
Found in plants.
Straight chain of glucose molecules
Few side branches.
Glycogen.
Found in animals (called “animal starch”).
Highly branched polymer of glucose
Many side branches

10. Polysaccharides (carbohydrates) Structural Forms
Cellulose - Primary constituent of plants cell walls; Not easily digested;.
Grazing animals can digest cellulose due to special stomachs and bacteria.
Cotton - nearly pure cellulose.
Chitin - Found in exoskeleton of animals like lobsters and insects; Polymer of glucose with amino acid attached to each.

12. Chitin (carbohydrates) Structural Forms
Modified form of cellulose

13. Test for Simple Sugars Benedict’s Reagent + Heat (boiling)
Positive = Brick Red/Orange

14. Test for Starch
Lugol’s Iodine

15. Review Describe the skeleton structure of carbohydrates.
What is the most metabolically important carbohydrate?
Describe the carbohydrate form(s) used to store excess energy resources in plants, animals and fungi.
Identify the major carbohydrate polymers and their respective biological functions.
How are polymers made from simple sugars.