1. Carbohydrates

2. OH H HO
CH2OH O
Carbohydrates:
Energy molecules

3. sugar - sugar - sugar - sugar - sugar
Carbohydrates
Building block molecules =
sugars
sugar - sugar - sugar - sugar - sugar
sugar

4. Carbohydrates Function: Examples quick energy energy storage structure
cell wall in plants
Examples
sugars
starches
cellulose (cell wall)
glucose C6H12O6
sucrose
starch

5. Sugars = building blocks
Names for sugars usually end in
glucose
fructose
sucrose
maltose
-ose OH H HO
CH2OH O
glucose
C6H12O6
fructose
maltose
sucrose

6. Building carbohydrates
Synthesis
1 sugar = monosaccharide
2 sugars = disaccharide |
glucose |
glucose |
maltose
mono = one
saccharide = sugar
di = two

7. Building carbohydrates
Synthesis
1 sugar = monosaccharide
2 sugars = disaccharide |
glucose |
fructose |
sucrose
(table sugar)
How sweet it is!

8. BIG carbohydrates Polysaccharides large carbohydrates starch glycogen
energy storage in plants
potatoes
glycogen
energy storage in animals
in liver & muscles
cellulose
structure in plants
cell walls
chitin
structure in arthropods & fungi
exoskeleton
poly = many

9. Building BIG carbohydrates
glucose + glucose + glucose… =
polysaccharide
starch
(plant)
energy storage
glycogen
(animal)

10. Digesting starch vs. cellulose
enzyme
starch easy to digest
Animals do not have the enzyme to digest cellulose. We need the help of bacteria living in our intestines.
enzyme
cellulose hard to digest

11. Cellulose Cell walls in plants herbivores can digest cellulose well
most carnivores cannot digest cellulose
that’s why they eat meat to get their energy & nutrients
cellulose = roughage
stays undigested
keeps material moving in your intestines
Cross-linking between polysaccharide chains = rigid & hard to digest
The digestion of cellulose governs the life strategy of herbivores.
Either you do it really well and you’re a cow or an elephant or a horse (spend a long time digesting a lot of food with a little help from some microbes & have to walk around slowly for a long time carrying a lot of food in your stomach)
Or you do it inefficiently and have to supplement your diet with simple sugars, like fruit and nectar, and you’re a gorilla.

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

13. Helpful bacteria How can cows digest cellulose so well?
BACTERIA live in their stomachs & help digest cellulose-rich (grass) meals
Eeeew… Chewing cud?