1. Lipids (fats)
Main Function: long-term energy storage
Special Feature: contain more energy per gram than
any other biological molecule (9 cal/g)
Groupings: Mostly C and H atoms (hydrocarbons)
Types: 1. Fats and oils Steroids
2. Phospholipids
Animal fat room temp)
Plant oils room temp) 1 2 3 4
Which are made of
which contain
Carbohydrates
Fats/oils
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,
main function
main function
main function
main function
CATALYSIS
&
STRUCTURE
/SUPPORT
ENCODING
HEREDITARY
INFORMATION
ENERGY
STORAGE
ENERGY
STORAGE
short-term
long-term

2. Structure of Lipids (fats)1 2 3
Glycerol
Fatty acids

3. Courtesy of Dr. Ceddia – York UniversityFA
Glycerol FA
= TG (Triglyceride) FA
Lipid droplet TG TG TG TG TG TG
Adipocytes (rat)
Courtesy of Dr. Ceddia – York University

4. Making and Breaking Lipids (fats)
Fats and oils are called triglycerides because of their structure 1
What functional groups are present on the glycerol and fatty acid molecules?
Ester linkage
+ 3 H2O
Condensation
Synthesis
Hydrolysis
main function
ENERGY
STORAGE
short-term

5. Types of Fatty Acids Saturated Unsaturated Polyunsaturated
Saturated
Unsaturated
Polyunsaturated
# of double bonds between carbons
Orientation
State at Room Temp.
Origin
Which are better for you?
Example
Types of Fatty Acids

6. Types of Fatty Acids Saturated Unsaturated Poly - unsaturated
# of Double Bonds between Carbons
At least one double bond between carbon atoms
None
(contains maximum # of H atoms)
Several double bonds

7. Types of Fatty Acids
Fewer hydrogens – “unsaturated”

8. Types of Fatty Acids Saturated Unsaturated Poly - unsaturated
Orientation of Fatty Acids
Kinks / bends at the double bonds
Kinks / bends at the double bonds
Straight chains

9. Types of Fatty Acids
CH2-CH
=CH
BEND DUE TO DOUBLE BOND

10. olive oil, vegetable oil, peanut oil, canola oil
Types of Fatty Acids
Saturated
Unsaturated
Poly - unsaturated
Examples
butter,
lard
olive oil, vegetable oil, peanut oil, canola oil

11. Trans Fat Types of Fatty Acids
Taking a perfectly good fat and making it bad!
Addition of hydrogen atoms to the acid, causing double
bonds to become single ones.
(unsaturated becomes saturated) LDL HDL

12. Phospholipids
Fat derivatives in which one fatty acid has been replaced by a phosphate group and one of several nitrogen-containing molecules.
an important part of the cell membrane (phospholipid bilayer)

13. Phospholipids
Nitrogen-containing
group

14. The phospholipid can also be represented as:
Phospholipids
The phospholipid can also be represented as:
Polar Head – hydrophilic
(water-loving)
Non-Polar Tails (fatty acids) – hydrophobic (water-hating)

15. Steroids consist of 4 fused carbon rings
Testosterone
Cholesterol
Precursor for other steroids
Component of animal cell membranes
Contributes to atherosclerosis