1. SBI4U BIOCHEMISTRY
Biological Macromolecules

2. Essential Questions:
What are the 4 main types of biological macromolecules and what is their function within cells?
How does the structure of each macromolecule contribute to their function within cells?

3. Carbon: The Central Atom
What’s so special about ?
The diversity of life relies on carbon!!!
Virtually all chemicals of life are carbon based – called organic compounds.
It can form four covalent bonds
C-C bonds enable carbon to form a variety of
geometrical structures (e.g., straight chains, branched chains, rings)
Methane
CH4
+ CH2
Ethane
C2H6
+ C4
Benzene
C6H6

4. Molecular Isomers: The same, yet different
What’s so special about ?
Carbon forms isomers!
Isomer – an organic compound with the same molecular formula, but different structure
Fructose
(fruit sugar)
Galactose
(milk sugar)
C6H12O6
Glucose
(simple sugar)
Example: C
Metabolized by cells differently due to structure
Structural isomers

6. Consider the following structures…
Are these structures atoms, compounds?

7. What is the relationship between atoms, bonding and macromolecules?
Bond together to form…
Molecules
Bond together to form…
Macromolecules

8. Macromolecules and their subunits
Monomer + =
Polymer
Macromolecule
glucose
glycogen
smaller subunits that make up a polymer
long chain
of monomers

9. Macromolecules and their subunits
Carbon
Compounds
include
Which are made of
which contain
Carbohydrates
Lipids
Nucleic acids
(e.g.,DNA/RNA)
Proteins
Simple sugars
(e.g., glucose)
Glycerol &
3 Fatty Acids
Nucleotides
Amino Acids
Carbon,
hydrogen,
oxygen
Carbon, hydrogen
oxygen, nitrogen,
phosphorus
hydrogen, oxygen,
nitrogen, 1 2 3 4
main function
main function
main function
main function
ENERGY
STORAGE
ENERGY
STORAGE
CATALYSIS
&
STRUCTURE
/SUPPORT
ENCODING
HEREDITARY
INFORMATION
short-term
long-term

10. Carbohydrates 1 2 3 4 Composition: C, H, and O atoms (1 : 2 : 1 ratio)
Main Function: quick and short-term energy storage
Composition: C, H, and O atoms (1 : 2 : 1 ratio)
Two types: 1. Simple Carbohydrates (monosaccharides and disaccharides)
2. Complex Carbohydrates (polysaccharides)
Carbon
Compounds
include
Which are made of
which contain
Carbohydrates
Lipids
Nucleic acids
Proteins
Simple sugars
(e.g., glucose)
Glycerol &
3 Fatty Acids
Nucleotides
Amino Acids
Carbon,
hydrogen,
oxygen
Carbon, hydrogen
oxygen, nitrogen,
phosphorus
hydrogen, oxygen,
nitrogen, 1 2 3 4
main function
ENERGY
STORAGE
short-term

11. Carbohydrates – Simple (glucose)
Monosaccharides
Carbohydrate molecule with 3-7 carbon atoms. (mono = one, saccharide = sugar)
Broken down quickly in the body to release energy.
e.g., GLUCOSE – hexose (six-carbon) sugar with 7
energy-storing C-H bonds
C6H12O6 1 2 3 4 5 6
Primary source of energy used by all cells

12. Disaccharides
Disaccharide: A compound composed of 2 monosaccharide subunits ex. lactose, maltose, sucrose
Condensation/Dehydration Reaction: Process by which disaccharides are formed
Hydrolysis Reaction: Process by which a disaccharide is split into 2 monosaccharides

13. Making & Breaking Carbohydrates
monosaccharide +
disaccharide (di = two)
Condensation (dehydration) synthesis
Hydrolysis
Two important
biochemical reactions

14. Carbohydrates – Complex (Polysaccharides)
Main Function: quick and short-term energy storage
Contain many units of glucose in long chains
Examples: Starch, glycogen, cellulose, chitin
Starch Granules (purple) in Potato Cells
Starch = energy storage in
plants

15. Carbohydrates – Complex (Polysaccharides)
Glycogen (polymer)
Glucose (monomer)
Glycogen = energy storage
in animals
muscle
liver
Glycogen (red) in Hepatocytes (liver cells)

16. Carbohydrates – Complex (Polysaccharides)
Cellulose fibers
Cellulose = polysaccharide
found in plant cell walls giving walls structure and strength
Macrofibril
Microfibril
Chains of
cellulose

17. Carbohydrates – Complex (Polysaccharides)
What is the difference between starch and cellulose?
Starch
Cellulose

18. Make a Venn Diagram!
Starch
Cellulose

19. Glucose repeat units are facing the same direction
Starch
Cellulose
Glucose repeat units are facing the same direction
Each successive glucose unit is upside-down in relation to each of the glucose molecules that it is connected to
Both polymers
Same monomer
(glucose)
Weaker Structure
Stronger (good for building)
Enzymes to digest
Cannot digest (no enzymes)
Insoluble (fiber / roughage)
Soluble