1. Building Blocks of Life
Chemistry of Carbon
Building Blocks of Life

2. Why study Carbon? All of life is built on carbon Cells ~72% H2O
~25% carbon compounds
carbohydrates
lipids
proteins
nucleic acids
~3% salts
Na, Cl, K…
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

3. Chemistry of Life Organic chemistry is the study of carbon compounds.
All living things have carbon in it! Therefore…all living things are organic!
C atoms are versatile building blocks
Very reactive atom.
Outer most shell needs four more electrons to be full or stable.
Can form up to 4 stable covalent bonds
Carbon chemistry = organic chemistry
Why is it a foundational atom?
What makes it so important?
Can’t be a good building block if you only form 1 or 2 bonds.

4. Let’s review the hierarchy of life
Atom
Element
Molecule
Organelle
Cell
Tissue
Organ
Organ system
Organism
Population
Community
Ecosystem
Biosphere
Whew! Glad you didn’t forget that!
Did I mention this will be on your final exam in May?

5. We are adding 3 more! Atom Element Molecule Monomers Polymers
Macromolecule
Organelle
Cell
Tissue
Organ
Organ system
Organism
Population
Community
Ecosystem
Biosphere

6. What is a monomer? What does the prefix “mono” mean? ONE!
A single (one unit) that are building blocks of larger molecules.
LEGO?
LETTERS of the alphabet? B I O S F U N

7. MONO+MONO+MONO+MONO=POLY
What is a polymer?
MONO+MONO+MONO+MONO=POLY
What does the prefix “poly” mean?
MANY!
Polymers are many monomers joined together
LETTERS of the alphabet?
Consider the previous slide… B I O S F U N
BIO Is
fun

8. Dehydration synthesis
Polymers
Long molecules built by linking repeating building blocks in a chain
monomers
Think individual legos!
building blocks
repeated small units
Held together by
covalent bonds
H2O HO H
• great variety of polymers can be built from a small set of monomers
• monomers can be connected in many combinations like the 26 letters in the alphabet can be used to create a great diversity of words
• each cell has millions of different macromolecules
Dehydration synthesis

9. Dehydration Synthesis or Condensation Reaction.

10. You gotta be open to “bonding!
How to build a polymer
You gotta be open to “bonding!
Synthesis
joins monomers by “taking” H2O out
one monomer donates OH–
other monomer donates H+
together these form H2O
requires energy & enzymes
H2O HO H
enzyme
Dehydration synthesis
Condensation reaction

11. Hydrolysis or Digestion

12. How to break down a polymer
Breaking up is hard to do!
Digestion
use H2O to breakdown polymers
reverse of dehydration synthesis
cleave off one monomer at a time
H2O is split into H+ and OH–
H+ & OH– attach to ends
requires enzymes
releases energy
H2O HO H
enzyme
Most macromolecules are polymers
• build:
condensation (dehydration) reaction
• breakdown:
hydrolysis
An immense variety of polymers can be built from a small set of monomers
Hydrolysis
Digestion

13. What is a macromolecule?
What does the prefix “micro” mean?
SMALL
What does the prefix “macro” mean?
LARGE!
Macromolecules are many monomers and/or polymers joined together to form very LARGE molecules.

14. BIO + IS + FUN = BIO IS FUN
Letters of the alphabet represent monomers.
Letters combine to make words represent monomers combining to make polymers.
Combing words to make sentences represent combining polymers to make macromolecules!

15. Building Blocks of Life
The 4 Macromolecules
Building Blocks of Life

16. Macromolecules
Smaller organic molecules join together to form larger molecules
macromolecules
4 major classes of macromolecules:
carbohydrates
lipids
proteins
nucleic acids

17. Carbohydrates

18. OH H HO
CH2OH O
Carbohydrates
energy molecules

19. Carbohydrates are composed of C, H, O
(CH2O)x C6H12O6
Monomers: simple sugars (single sugars) or monosacharride (prefix mono=one & suffix saccharide = sugar ). 3 monosaccharides :
Glucose, fructose and galactose
(CH2O)x
C6H12O6
carb = carbon
hydr = hydrogen
ate = oxygen compound
sugar

20. ex: sugars, starches, cellulose
Function:
Dietary energy u energy storage
raw materials u structural materials
ex: sugars, starches, cellulose

21. 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

22. More sugars! Disaccharides = 2 sugars Polysaccharides = many sugars
Sucrose,
maltose,
lactose
Polysaccharides = many sugars
large polymers
Starch
Glycogen
Cellulose
Chitin

23. The bond that joins monosaccharides to create polysaccharides
Building sugars
Dehydration synthesis
monosaccharides
disaccharide
H2O
maltose |
glucose |
glucose |
maltose
glycosidic linkage
The bond that joins monosaccharides to create polysaccharides

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

25. 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)
Polysaccharides are polymers of hundreds to thousands of monosaccharides

26. Linear vs. branched polysaccharides
slow release
starch
(plant)
energy storage
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
glycogen
(animal)
fast release

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

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

29. 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
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.

30. 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
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

31. Helpful bacteria How can herbivores digest cellulose so well?
BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals

32. Let’s build some Carbohydrates!
EAT X
Let’s build some
Carbohydrates!