1. Carbohydrates Carbohydrates are composed of C, H, O carbo - hydr - ate
(CH2O)x C6H12O6
Function:
energy - energy storage
raw materials - structural materials
Monomer: sugars
ex: sugars & starches

2. Sugars Most names for sugars end in -ose
Classified by number of carbons
6C = hexose (glucose)
5C = pentose (fructose, ribose)
3C = triose (glyceraldehyde)

3. What functional groups?
Carbonyl
Aldehyde
Ketone

4. Numbered Carbons 5C & 6C sugars form rings in aqueous solutions
Where do you find aqueous solutions?
In cells!

5. Simple and Complex Sugars
Monosaccharides
simple 1 monomer sugars
glucose
Disaccharides
2 monomers
sucrose
Polysaccharides
large polymers
starch

6. Building Sugars
Dehydration synthesis

7. Building Sugars
Dehydration Synthesis

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

9. Branched vs. Linear Polysaccharides
What does branching do?

10. Polysaccharide Diversity
Molecular structure determines function
Isomers of glucose
How does structure determine function?

11. Digesting starch vs. cellulose
____ to digest
Cellulose:

12. Cellulose
Most abundant organic compound on Earth
So What?

13. Cow
can digest cellulose well; no need to eat supplemental sugars
Gorilla
can’t digest cellulose well; must supplement with sugar source, like fruit

14. Macromolecules
Lipids

15. Lipids Lipids are composed of C, H, O Diverse group
long hydrocarbon chain
Diverse group
fats
phospholipids
steroids
Do not form polymers
big molecules made of smaller subunits
not a continuing chain

16. Fat subunits Structure: glycerol (3C alcohol) + fatty acid
long HC “tail” with COOH group at “head”
Dehydration Synthesis

17. Building Fats Triacylglycerol 3 fatty acids linked to glycerol
ester linkage = between OH & COOH

18. Dehydration Synthesis

19. Fat Stores Energy Long HC chain Function: polar or non-polar?
hydrophilic or hydrophobic?
Function:
energy storage
very rich
2x carbohydrates
cushion organs
insulates body
think whale blubber!

20. Saturated Fats All C bonded to H No C=C double bonds
long, straight chain
most animal fats
solid at room temp.
contributes to cardiovascular disease (atherosclerosis) = plaque deposits

21. Unsaturated Fats C=C double bonds in the fatty acids plant & fish fats
vegetable oils
liquid at room temperature
the kinks made by double bonded C prevent the molecules from packing tightly together

22. Phospholipids Structure: glycerol + 2 fatty acids + PO4
PO4 negatively charged

23. Phospholipids Hydrophobic or hydrophilic?
fatty acid tails = hydrophobic
PO4 = hydrophilic head
dual “personality”
interaction with H2O is complex & very important!

24. Phospholipids in Water
Hydrophilic heads attracted to H2O
Hydrophobic tails “hide” from H2O
self-assemble into aggregates
“micelle”
bilayer
early evolutionary stage of cell?

25. So…why is this important?
Phospholipids create a barrier in water
define outside vs. inside
cell membranes

26. Phospholipids and Cells
Phospholipids of cell membrane
double layer = bilayer
hydrophilic heads on outside
in contact with aqueous solution
hydrophobic tails on inside
form core
forms barrier between cell & external environment

27. Steroids ex: cholesterol, sex hormones 4 fused C rings
different steroids created by attaching different functional groups to rings

28. Cholesterol Important cell component
animal cell membranes
precursor of all other steroids
including vertebrate sex hormones
high levels in blood may contribute to cardiovascular disease

29. Cholesterol
Helps keep membrane fluid and flexible

30. From Cholesterol → Sex Hormones
What a big difference a few atoms can make!