Carbohydrates

1
Carbohydrates
2
Carbohydrates
energymolecules
3
Carbohydrates

• Carbohydrates are composed of C, H, O
• carbo - hydr - ate
• CH2O
• (CH2O)x C6H12O6
• Function
• energy u energy storage
• raw materials u structural materials
• Monomer sugars
• ex sugars, starches, cellulose

C6H12O6
(CH2O)x
4
Sugars

• Most names for sugars end in -ose
• Classified by number of carbons
• 6C hexose (glucose)
• 5C pentose (ribose)
• 3C triose (glyceraldehyde)

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 solutionsin biology? In cells!
Carbons are numbered
7
Numbered carbons
C
6'
C
O
5'
C
C
1'
4'
energy stored in C-C bonds
C
C
2'
3'
8
Simple complex sugars

• Monosaccharides
• simple 1 monomer sugars
• glucose
• Disaccharides
• 2 monomers
• sucrose
• Polysaccharides
• large polymers
• starch

9
Building sugars

• Dehydration synthesis

monosaccharides
disaccharide
glucose
glucose
maltose
glycosidic linkage
10
Building sugars

• Dehydration synthesis

monosaccharides
disaccharide
fructose
glucose
sucrose (table sugar)
11
Polysaccharides

• Polymers of sugars
• 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 doesbranching do?
energystorage
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
starcheasy todigest
cellulosehard todigest
15
Cellulose

• Most abundant organic compound on Earth
• herbivores have evolved a mechanism to digest
  cellulose
• most carnivores have not
• thats why they eat meat to get their energy
  nutrients
• cellulose undigestible roughage

But it tasteslike hay!Who can liveon this
stuff?!
16

• Cow
• can digest cellulose well no need to eat other
  sugars
• Gorilla
• cant digest cellulose well must add another
  sugar source, like fruit to diet

17
Helpful bacteria

• How can herbivores digest cellulose so well?
• BACTERIA live in their digestive systems help
  digest cellulose-rich (grass) meals

Coprophage
Ruminants
18
EAT
X

• Lets build some
• Carbohydrates!