1. Modified from Kim FogliaOH H HO
CH2OH O
Carbohydrates
Modified from Kim Foglia

2. Carbohydrates are composed of C, H, O carbo - hydr - ate
(CH2O)x C6H12O6
Function:
energy u energy storage
raw materials u structural materials
Monomer: sugars
ex: sugars & starches
carb = caron
hydr = hydrogen
ate = oxygen compound

3. Sugars 6 5 3 Most names for sugars end in -ose
Classified by number of carbons
6C = hexose (glucose)
5C = pentose (fructose, ribose)
3C = triose (glyceraldehyde)
Glyceraldehyde H OH O C OH H HO
CH2OH O
Glucose
CH2 OH HO O H
Fructose
CH2OH 6 5 3

4. What functional groups?
carbonyl
aldehyde
carbonyl
ketone

5. Sugar structure 5C & 6C sugars form rings in aqueous solutions
Carbons are numbered

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

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

8. Building sugars Dehydration synthesis monosaccharides disaccharide |
glucose |
glucose |
maltose
maltose
glycosidic linkage

9. Building sugars Dehydration synthesis monosaccharides disaccharide |
glucose |
fructose |
sucrose
sucrose = table sugar
structural isomers
glycosidic linkage

10. 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)
Polysaccharides are polymers of hundreds to thousands of monosaccharides

11. Branched vs. linear polysaccharides
Can you see the difference between starch & glycogen?
Which is easier to digest?
Glycogen = many branches = many ends
Enzyme can digest at multiple ends. Animals use glycogen for energy storage == want rapid release.
Form follows function.
APBio/TOPICS/Biochemistry/MoviesAP/05_07Polysaccharides_A.swf

12. Polysaccharide diversity
Molecular structure determines function
isomers of glucose
how does structure influence function…

13. Digesting starch vs. cellulose
enzyme
starch easy to digest
Starch = all the glycosidic linkage are on same side = molecule lies flat
Cellulose = cross linking between OH (H bonds) = rigid structure
enzyme
cellulose hard to digest

14. Cellulose Most abundant organic compound on Earth
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 (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.

15. Cow
can digest cellulose well; no need to eat supplemental sugars
Gorilla
can’t digest cellulose well; must supplement with sugar source, like fruit
The digestion of cellulose governs the life strategy of herbivores.
Either you do it really well and you’re a cow or an elephant (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.
APBioTOPICS/20Biochemistry/MoviesAP/Macromolecule-Lifewire.swf

16. Glycemic index Which food will get into your blood more quickly? apple
rice cakes
corn flakes
bagel
peanut M&M

17. Glycemic index
Ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar) levels
Carbohydrate foods that breakdown quickly during digestion have the highest glycemic index. Their blood sugar response is fast & high.

18. Glycemic index Which food will get into your blood more quickly?
apple 36
rice cakes 82
corn flakes 84
bagel 72
peanut M&M 33
Why do we find sweet foods pleasurable to eat?
Why are we attracted to sweet food?