1. Carbohydrates

2. OH H HO
CH2OH O
Carbohydrates
energy molecules

3. Carbohydrates are composed of C, H, O
(CH2O)x C6H12O6
Function:
energy u energy storage
raw materials u structural materials
Monomer: sugars
ex: sugars, starches, cellulose
(CH2O)x
C6H12O6
sugar

4. Sugars 6 5 3 Most names for sugars end in -ose
Classified by number of carbons
6C = hexose (glucose)
5C = pentose (ribose)
3C = triose (glyceraldehyde)
Glyceraldehyde H OH O C OH H HO
CH2OH O
Glucose H OH HO O
Ribose
CH2OH 6 5 3

5. Functional groups determine function
carbonyl
aldehyde
carbonyl
ketone

6. Sugar structure 5C & 6C sugars form rings in solution
Where do you find solutions in biology?
In cells!
Carbons are numbered

7. Numbered carbons C C O C C C C energy stored in C-C bonds 5' 4' 1' 3'6' C O 5' C C 4' 1'
energy stored in C-C bonds C C 3' 2'

8. Simple & complex sugarsOH H HO
CH2OH O
Glucose
Simple & complex sugars
Monosaccharides
simple 1 monomer sugars
glucose
Disaccharides
2 monomers
sucrose
Polysaccharides
large polymers
starch

9. Building sugars Dehydration synthesis monosaccharides disaccharide H2O|
glucose |
glucose

10. Building sugars Dehydration synthesis monosaccharides disaccharide H2O|
glucose |
fructose |
sucrose
(table sugar)

11. Polysaccharides Polymers of sugars Function:
costs little energy to build
easily reversible = release energy
Function:
energy storage
starch (plants)
glycogen (animals)
in liver & muscles
structure
cellulose (plants)
chitin (arthropods & fungi)

12. Linear vs. branched polysaccharides
slow release
starch
(plant)
What does branching do?
energy storage
glycogen
(animal)
fast release

13. Polysaccharide diversity
Molecular structure determines function
in starch
in cellulose
isomers of glucose
structure determines function…

14. Digesting starch vs. cellulose
enzyme
starch easy to digest
cellulose hard to digest
enzyme

15. Cellulose Most abundant organic compound on Earth
herbivores have evolved a mechanism to digest cellulose
most carnivores have not
that’s why they eat meat to get their energy & nutrients
cellulose = undigestible roughage
But it tastes like hay! Who can live on this stuff?!

16. Cow Gorilla can digest cellulose well; no need to eat other sugars
can’t digest cellulose well; must add another sugar source, like fruit to diet

17. Helpful bacteria Caprophage Ruminants
How can herbivores digest cellulose so well?
BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals
Caprophage
I eat WHAT!
Tell me about the rabbits, again, George!
Ruminants