Lipids Flashcards
What is the main purpose of lipids? (mainly triglycerides)
To serve as a reserve supply of energy during periods of low food consumption.
Pre-cursors to triglycerides. A source of energy
Fatty acids
Triglycerides role
Energy storage, thermal insulation, filling space, binding organs together and cushioning them
Role of phospholipids
Structural component of cell and organelle membranes. Aids in fat digestion.
Role of sphingolipids
Structural component of cell membranes (especially in nerve cells) chemical messengers
Cholesterol role
Component of cell membranes. Precursor of other steroids such as hormones and bile salts.
Role of bile fats
Aid in digestion and nutrient absorption. A form of steroid.
Fat soluble vitamins
ADEK.
Involved in a variety of functions including blood clotting, wound healing, vision, calcium absorption.
The 4 fat soluble vitamins
ADEK
Eicosanoids role
Chemical messengers
What do lipids mainly consist of?
Carbon, hydrogen and some oxygen.
Lipids are classified based on what
Their structure.
- Simple lipids (esters of fatty acids)
- Complex lipids (Esters of fatty acids + additional groups)
- Derived lipids (derived from hydrolysis of simple/complex lipids)
What is a fatty acid?
A hydrocarbon chain with a carboxyl group at one end (COOH). Typically has an even number of carbons (10-30)
Saturated and unsaturated fatty acids
Saturated fatty acids have all single bonds and are completely saturated with hydrogen.
Unsaturated fatty acids have at least 1 double bond (can be either trans or cis) and therefore, cannot be completely saturated.
What is the most naturally occurring unsaturated fatty acid
The Cis unsaturated fatty acid. This type of fat is bent, and therefore not tightly packed. This results in it being a liquid at room temperature such as vegetable oil.
Trans unsaturated fat
2 hydrogens attached to the double bond on opposite sides. Most are created in an industrial process that was recently banned by the FDA. Hydrocarbon chain is straight/linear and is therefore able to pack together closely to make a solid at room temperature
Saturated fatty acid qualities
Linear molecule that is solid at room temperature.
What is an ester of a fatty acid?
Alcohol + fatty acid.
An alcohol compound contains a hydroxyl group (OH) attached to carbon.
Examples of alcohol include Glycerol and sphingosine.
2 types of alcohol
Glycerol and sphingosine
Triglycerides are which type of lipids?
Simple. They have 3 fatty acid chains (carboxylic acid and hydrocarbon chain) + glycerol (alcohol). This is the storage form of fatty acids.
What is the most common saturated fat in plants and animals?
Palmitic acid. This acid may compromise over half of the total saturated fat intake in the united states. Makes up approx a quarter of the fat in red meat and dairy.
What are complex lipids and give 2 examples
Esters of fatty acids + additional groups.
Phospholipids and sphingolipids
What is an ester
An chemical compound derived from alcohol
What are phospholipids composed of?
Phospholipids are a form of complex lipids. Contains 2 fatty acids + glycerol (ester of fatty acid) + phosphate + 1 polar group.
Polar groups include- Ethanolamine Choline Serine Inositol
4 polar groups possible to create a phospholipid
Ethanolamine, choline, serine, and inositol
Eyes cause some issues
What are sphingolipids composed of
Fatty acid + sphingosine + head group
Possible head groups:
Hydrogen (Ceramide)
Phosphocholine (sphingomyelin)
Sugar (glycolipid, 1 sugar= cerebroside. more than 1 sugar = ganglioside)
3 groups of derived lipids
- Steroids
- Isoprenoids
- Eicosanoids
Examples of steroids
Sterols, steroid hormones and bile salts
Types of steroid hormones
mineralocorticoids (corticosterone, aldosterone) glucocorticoids (cortisol) Progesterone, testosterone, estrogen, vita D
Isoprene subunits
Unsaturated pentahydrocarbon
Examples of isoprenoids
Fat soluble A E K
Eicosanoids
Derived from arachidonic acid.
Examples- Prostoglandins, leukotrienes, thromboxanes
How do steroids bind to receptors
They bind to receptors inside of cells
