CHAPTER FIFTEEN: LIPIDS Flashcards
What are LIPIDS?
What does the Greek word “lipid” mean?
A family of biomolecules that have the common property of being soluble in organic solvents but not in water.
Lipid (Greek)= fat, lard
What are the characteristics of these types of lipids?
* waxes, fats, oils and glycerophospholipids
* steroids
*
- fatty acids: esters that can be hydrolyzed to give fatty acids and other products including an alcohol (tail)
- steroids: the steroid nucleus of four fused carbon rings. Do not contain fatty acids and cannot be hydrolyzed.
What are the function of LIPIDS in the body?
they provide energy and protection and insulation for the organs
What is a FATTY ACID?
The simplest type of lipids and found as components in more complex lipids. Contains a long, unbranched carbon chain attached to a carboxylic acid group at one end.
The long chain makes them insoluble in water.
Naturally occurring fatty acids have an ____ (even or odd) number of carbon atoms, usually between ___ and ___.
Even; 10 and 20
What is a SATURATED FATTY ACID?
What is the difference between a MONOUNSATURATED and a POLYUNSATURATED FATTY ACID?
Saturated: the long carbon chain is like an alkane because there are only single carbon-carbon bonds.
Mono: one double bond (properties similar to alkene)
Poly: at least 2 C-C bonds
What are ESSENTIAL FATTY ACIDS?
The polyunsaturated fatty acids that must be obtained from the diet.
Most SATURATED fats are ______ at room temperature.
Most UNSATURATED fats are ______ at room temperature.
solids
liquid oils
What are PROSTAGLANDINS?
How are they formed?
What other name are they known by?
hormone-like substances produced in small amounts in most cells in the body.
Formed from arachidonic acid, the polyunsatured fatty acid with 20 carbon atoms.
Eicosanoids (Greek word for 20)
What is the difference between between PROSTAGLANDIN E and F?
E= soluble in ether
F= soluble in phosphate buffer, starts with an F in Swedish
The various kind of PROSTAGLANDINS differ by the substituents attached to the 5-carbon ring. What are the differences between:
- PGE
- PGF
The number of double bonds is shown as a subscript _____ or ______.
PGE= has a ketone group on carbon 9
PGF= has a hydroxyl group on carbon 9
1 or 2
PROSTAGLANDINS are broken down quickly , but have ________ physiological effects.
Name some of these.
potent
Raise/lower blood pressure, stimulate contraction and relaxation of smooth muscle, may cause inflammation and pain.
What is a WAX?
an ester of a saturated fatty acid and a long-chain alcohol, each containing from 14-30 carbon atoms.
What are TRIACYLGLYCEROLS?
They are also known as _______.
In a TRIACYLGLYCEROL, ____ hydroxyl groups on glycerol form ester bonds with the ________ groups of ____ fatty acids.
fatty acids are stored as fats and oils known as TRIACYLGLYCEROLS. They are trimesters of glycerol (a trihydroxy alcohol) and fatty acids.
TRIGLYCERIDES
3, carboxyl groups, 3
__________ are the major form of energy storage for animals.
TRIACYLGLYCEROLS
What is a FAT?
What is an OIL?
Fat= a TRIACYLGLYCEROL that is solid at room temperature and usually comes from animal sources.
Oil= a TRIACYLGLYCEROL that is usually a liquid at room temperature and is obtained from a plant source.
Which has a higher melting point and why?
- Saturated fatty acids
- Unsaturated fatty acids
Saturated because they pack together more tightly.
Animal fats usually contain more ______ fatty acids than do vegetable oils.
saturated
In the HYDROGENATION of an unsaturated fat, hydrogen is added to one or more carbon-carbon _______ bonds to form carbon-carbon _______ bonds.
double, single
What are LIPASES?
What are the products of hydrolysis of the ester bonds?
TRIACYLGLYCEROLS are hydrolyzed (split by water) in the presence of strong acids or digestive enzymes called LIPASES.
glycerol and 3 fatty acids.