Lipids and Cell Membranes Flashcards
Lipid
Lipids are defined as molecules that are not soluble in water, but are soluble in organic solvents.
What are the five types of lipids
- Free fa)y acids: A common fuel.
- Triacylglycerols: Storage form of fa>y acids.
- Phospholipids: Membrane lipids.
- Glycolipids: Membrane lipids composed in part of carbohydrates.
- Steroids: Polycyclic hydrocarbons with a variety of functions
What are some characteristics of fatty acids?
Chains of hydrogen-bearing carbon atoms
* Contain a carboxylic acid at one end and a methyl group at the other end
* Fatty acids may be saturated or unsaturated
Cis polyunsaturated fa/y acids
Cis polyunsaturated fatty acids are essential components of our diets because we cannot synthesize them
Triacylglycerols
Fatty acids are stored as triacylglycerols in which three fatty acids are esterified to one molecule of glycerol
The common types of membrane lipids are:
- Phospholipids
- Glycolipids
- Cholesterol
Phospholipids are composed of four components:
- Fatty acids (2 or more)
- Platform(glycerol or sphingosine)
- Phosphate
- Alcohol
sphingolipids
Phospholipids built on a sphingosine platform
Glycolipids
carbohydrate-containing lipids
Steroids
built on a tetracyclic platorm,consisting of three cyclohexane rings and a cyclopentane ring fused together
amphipathic
molecules containing hydrophobic and hydrophilic properties
Enhancements in Fatty Acid Fluidity occurs when there are
- Short chain length
- cis double bonds
Cerebrosides
glycolipid with glucose or galactose
progeria
Failure to remove a farnesyl group from lamin (a nuclear protein) results in:
* deformed nuclear membrane
* impaired nuclear function.
What form are fatty acids usually in
Because fatty acids are ionized at physiological pH, they are usually referred to as their carboxylate form, rather than the unionized acid
