Chapter 2.4 Lipids Flashcards
Lipid
Hydrophobic organic molecule made of carbon and a high ratio of hydrogen to oxygen
Lipids are less ______than carbohydrates and thus have more________
Less oxidized and have more calories per gram
Five primary types of lipids in humans
- Fatty acids
- Triglycerides
- Phospholipids
- Eicosanoids
- Steroids

Fatty acid
Chain of 4 to 24 carbons with a carboxyl group and a methyl group at either end. Saturated or unsaturated
Saturated fatty acid
Has as much hydrogen as it can carry
Unsaturated fatty acids
Hydrogen can be added to this molecule because some double covalent bonds
Polyunsaturated fatty acids
Multiple double carbon to carbon covalent bonds
Essential fatty acids
Obtain from diet, cannot synthesize them
Glycerol
A three carbon alcohol
Triglyceride
A glycerol linked to three fatty acids which makes it neutral; links formed by dehydration synthesis. 
Triglycerides are broken down by_____
Hydrolysis reactions
Triglycerides are also known as______
Neutral fats
Which fats contribute more to cardiovascular disease?
Saturated fats
Primary function of fat
Energy storage
Primary function of fat in adipose tissue
Thermal insulation and shock absorbing cushion for organs
Phospholipids are made of
Glycerol, two fatty acid tails, and a phosphate group which links to other functional groups
Nature of phospholipids
Clothespin: Tails are hydrophobic head is hydrophilic…so amphipathic
Most important function of phospholipid
Structural foundation of cell membranes
Eicosanoids structure
20 carbon compounds derived from arachidonic acid
Eicosanoids primary function
Hormone like chemical signals between cells
Prostaglandins function and shape
-Functionally diverse Eicosanoids (signaling in inflammation, blood clotting, hormone action, labor contractions, Control of blood vessel diameter, etc.)
-Five of the 20 carbon atoms arranged in a ring
Steroid
Lipid with 17 of its carbon atoms arranged in four rings
Cholesterol
Parents steroid from which other steroids are synthesized:
Cortisol, progesterone, estrogens, testosterone, and bile acids
We obtain dietary cholesterol from __________
Foods of animal origin
Cholesterol functions
Precursor of other steroids
Important component of cell membranes: required for proper nervous system function
Where is cholesterol primarily synthesized
the liver
Function of bile acids
Steroids that aid in fat digestion and nutrient absorption
Cholesterol function
Component of cell membranes and precursor of other steroids
Eicosanoids function
Chemical messenger between cells
Fat soluble vitamins A, D, E,K function
Blood clotting, wound healing, vision, calcium absorption, etc.
Fatty acids Function
Precursor of triglycerides; source of energy
Phospholipids Function
Major component of cell membranes; aid in fat digestion
Steroid hormones Function
Chemical messengers between cells
Triglycerides function
Energy storage
thermal insulation
filling space
binding organs together
cushioning organs
