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 3. Steroids 2. Phospholipids Animal fat (solid @ room temp) Plant oils (liquid @ 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

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

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

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

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

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

Types of Fatty Acids Fewer hydrogens – “unsaturated”

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

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

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

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

Phospholipids Fat derivatives in which one fatty acid has been replaced by a phosphate group and one of several nitrogen-containing molecules.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)

Phospholipids Nitrogen-containing group

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)

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