1. Lipids (fats)
Main Function: long-term energy storage
Special Feature: contain more energy per gram than any other biological molecule
Groupings: Mostly C and H atoms(hydrocarbons)
Types: 1. Triglycerides Steroids
2. Phospholipids
Animal fat room temp)
Plant oils room temp) 1 2 3 4
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,
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. 1. Triglycerides FA Glycerol FA = TG (Triglyceride) FA Structure
Triglycerides are composed of 1 glycerol + 3 fatty acids (16-18 Carbons long)
Formation and Breakdown
Triglycerides are formed through a condensation/dehydration reaction between the glycerol and each of the fatty acids.
Triglycerides are broken down into 1 glycerol and 3 fatty acids through hydrolysis
2 Types of Fatty Acids
Saturated
Unsaturated

4. Making and Breaking Lipids (fats)
Fats and oils are called triglycerides because of their structure 1
Ester linkage
+ 3 H2O
Condensation
Synthesis
Hydrolysis
main function
ENERGY
STORAGE
short-term

5. 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

6. Types of Fatty Acids: Saturated
Saturated Fats
Solid at room temperature
Contain only single C-C bonds (resulting in straight chains)
During digestion these are converted into “bad cholesterol” which can clog arteries
Ex. animal fats, butter

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

8. CH2-CH =CH Types of Fatty Acids BEND DUE TO DOUBLE BOND
How do you think this bend affects density???

9. Types of Fatty Acids: Unsaturated
Unsaturated Fats
Liquid at room temperature
Contain double C-C bonds (resulting in kinks in their chains)
Unsaturated fats with more than one double bond are called polyunsaturated fats
Ex. vegetable oils

10. Trans Fat Types of Fatty Acids
Taking a perfectly good fat and making it bad!
Unsaturated fat (contains double bonded carbons) that has the properties of a saturated fat
Often solid at room temperature
Bad for you! Also causes an increase in “bad cholesterol”

11. How Trans Fats Became out Enemy…
Fill out the question sheet while you watch this short YouTube clip

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 Structure:
Composed of glycerol, 2 fatty acids, and a phosphate-containing functional group
Phosphate head is hydrophillic (water-loving) and the fatty acid tails are hydrophobic (water-hating)
Why do you think the fatty acids are hydrophobic?
Why is the phosphate portion hydrophillic?

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 Testosterone Cholesterol
Very different structure to other lipids
Made of 4 fused carbon rings
Include hormones such as testosterone, estrogen, etc.