Lipids
the reaction of corn oil and hydrogen (H2) with a nickel catalyst
Hydrogenation
CH3-(CH2)12-COOH
Mystic acid
CH3-(CH2)7-CH=CH-(CH2)7-COOH
Oleic acid
CH3−(CH2)14−COOH
Palmitic acid
CH3−(CH2)5−CH=CH (CH2)7−COOH
Palmitoleic acid
Name the Monounsaturated fatty acids
Palmitoleic acid Oleic acid
Name all the unsaturated fats
Palmitoleic acid Oleic acid Linoleic acid Linolenic acid Arachidonic acid
A polyunsaturated fatty acid contains more than one
carbon-carbon double bond
Lipids are compounds that are soluble in
chloroform or ether
T or F Vegetable oils have higher melting points than fats
false
A triacylglycerol that is solid at room temperature is called a(n)
fat
Name all the lipids
fats (saturated fatty acids) oils (unsaturated fatty acids) glycerophospholipids triacylglycerols waxes steroids cholesterol
The products of the acid catalyzed hydrolysis of a fat are
fatty acids and glycerol
What are the products of saponification?
glycerol salts of fatty acids
What are the products of hydrolysis reaction in lipids?
glycerol and three fatty acids
the reaction of glyceryl trilinoleate from safflower oil with water and HCl
hydrolysis
the reaction of glyceryl tristearate with water in the presence of lipase enzyme
hydrolysis
Which of the following compounds is a glycerophospholipid?
lecithin
Name the omega 3 fatty acids.
linolenic acid
Compared to saturated fatty acids, unsaturated fatty acids have
lower melting points
The name of the reaction that occurs when a fat reacts with sodium hydroxide and water is
saponification
the reaction of palm oil with KOH
saponification
What is the product of hydrogenation reaction in lipids?
saturated fat (single bonds)
Which fatty acid are usually solids at room temperature?
saturated fatty acids
Cholesterol belongs to the ________ group of lipids.
steroids
Unsaturated fatty acids have lower melting points than saturated fatty acids because
the cis double bonds give them an irregular shape
T or F Hydrogenation of oils coverts some cis double bonds to trans double bonds
true
T or F There are more unsaturated fats in vegetable oils
true
Which of the following lipids will give a single molecule of fatty acid when hydrolyzed?
wax
CH3-(CH2)3-(CH2-CH=CH)4-(CH2)3-COOH
Arachidonic acid
Why does stearic acid melt at 69 ∘C but linoleic acid melts at −5∘C?
Because the molecules of A SATURATED FATTY ACID (like STEARIC ACID) fit closer together than the molecules of A POLYUNSATURATED FATTY ACID (like LINOLEIC ACID), there are STRONGER attractions between saturated fatty acid molecules, requiring MORE energy (HIGHER melting points) to break them apart and form liquid.
Lauric Acid
12 carbon saturated fatty acid no double bond
Mystic Acid
14 C saturated fatty acid no double bond
Palmitic acid
16 C Saturated fatty acid no double bond
Palmitoleic acid
16 C monounsaturated fatty acid 1 double bond starting at Carbon 9
Oleic acid
18 C monounsaturated fatty acid one double bond starting at Carbon 9
linoleic acid
18 C polyunsaturated fatty acid 2 double bonds at Carbon 9, 12
linolenic acid
18 C polyunsaturated fatty acid 3 double bonds on Carbon 9, 12, 15
stearic acid
18 C saturated fatty acid no double bonds
Describe some similarities and differences in the structures of a saturated fatty acid and an unsaturated fatty acid.
All fatty acids contain a LONG chain of carbon atoms with a CARBOXYLIC ACID GROUP. Saturated fatty acids contain ONLY CARBON-CARBON SINGLE BONDS; unsaturated fatty acids contain ONE OR MORE DOUBLE BONDS.
How does the structure of a fatty acid with a cis double bond differ from the structure of a fatty acid with a trans double bond?
In a CIS fatty acid, the hydrogen atoms are ON THE SAME SIDE of the double bond, which produces a kink in the carbon chain. In a TRANS fatty acid, the hydrogen atoms are ON OPPOSITE SIDES of the double bond, which gives a carbon chain without any kink.
How does the double bond influence the dispersion forces that can form between the hydrocarbon chains of fatty acids?
In unsaturated fatty acids, the cis double bonds cause the carbon chain to bend or "kink", which gives the molecules an irregular shape. As a result, unsaturated fatty acids cannot stack as closely as saturated fatty acids and thus have fewer dispersion forces between their carbon chains.
CH3-(CH2)10-COOH
Lauric acid
Name all the saturated fatty acid
Lauric acid Mystic acid Palmitic acid Stearic acid
CH3-(CH2)4-CH=CH-CH2-CH=CH-(CH2)7-COOH
Linoleic acid
CH3−(CH2)4−CH=CH−CH2−CH=CH−(CH2)7−COOH
Linoleic acid
Name the Omega-6 fatty acids
Linoleic acid Arachidonic acid
CH3-(CH2)16-COOH
Stearic acid
T or F Animal fats have more saturated fats
True
Waxes are lipids derived from
a long-chain alcohol and a long-chain fatty acid
arachidonic
20 C polyunsaturated fatty acid 4 double bonds on Carbon 5, 8, 11, 14
arachidic acid
20 C saturated fatty acid
Name the polyunsaturated fatty acid
Linoleic acid Linolenic acid Arachidonic acid
CH3-CH2-CH=CH-CH2-CH=CH-CH2-CH=CH-(CH2)7-COOH
Linolenic acid
Commercially, liquid vegetable oils are converted to solid fats such as margarine by
hydrogenation