Chapter 15: Lipids Flashcards
Lipids are ______ and ______. Which one can be hydrolyzed?
Esters; steroids. Esters can be hydrolyzed.
Do steroids (lipids) contain fatty acids?
No
Do esters contain fatty acids and other molecules?
Yes
_____ are characterized by the steroid nucleus of four fused carbon rings
steroids
Waxes fats, oils, and phospholipids are _________ that can be hydrolyzed to give fatty acids
lipids: esters
Lipids are naturally occurring biomolecules which are soluble in organic solvents but not in ______
water
“Long unbranched carbon chains with a carboxylic acid group at the end” what am I?
Fatty acids
How long are the chains of fatty acids?
12-18 carbon atoms
Why are fatty acids insoluble in water?
Because of the long carbon chains
Fatty acids can be __________, with only one double C=C bond in the carbon chain
monounsaturated
Fatty acids can be monounsaturated, with only one double _____ bond in the carbon chain
C=C
Which fatty acids can be drawn as cis and trans isomers?
Unsaturated fatty acids
True or false: almost all naturally occurring unsaturated fatty acids have one or more cis double bonds?
Very, very true
Humans can or cannot synthesized sufficient amounts of polyunsaturated fatty acids?
Cannot
Saturated fatty acids have double c=c bonds. True or false?
False, saturated fatty acids contain only single C-C bonds
______ fatty acids have higher melting points and are usually solids at room temperature
saturated
______ fatty acids have strong dispersion forces (non-polar/non-polar interactions) between long carbon chains
saturated
In _______ fatty acids, the ___ double bonds cause the carbon chain to kink or bend, giving the molecules an irregular shape
Unsaturated fatty acids; the cis double bonds
The reduced interactions in fatty acids with cis bonds _____ the melting point of the molecules
reduces
In unsaturated fatty acids, the cis double bonds cause what?
Causes the carbon chain to bend or kink, giving the molecules an irregular shape and allowing fewer interactions between molecules
______ are hormone-like substances produced in cells
Prostaglandins
Prostaglandins are also known as _____
eicosanoids, formed from arachidonic acids
when tissue is injured, _______ acid is converted to prostaglandins that produce inflammation and pain in the area
arachidonic
waxes are ______ of saturated fatty acids and long-chain alcohols, each containing from 14-30 carbon atoms
esters
What are waxes
Esters of saturated fatty acids, and create coats on many plants to help them be waterproof
________ are the major form of energy storage for animals
Triacylglycerols
Recognize the condensed structural formula of a triacylglycerol….google it or look through the lecture
:)
Do saturated or unsaturated fatty acids have higher melting points? Why?
saturated because they pack together more tightly
Saturated acids are usually found in _____ fat and in coconut and palm oils
animal
In ________ reactions, double bonds in unsaturated fatty acids react with hydrogen gas to produce c-c single bonds
Hydrogenation
Unsaturated fatty acids, unlike saturated, can be ____ and ____
cis and trans
Lipids with multiple hexane structures and one pentane structure are _______
steroids
What are the four sub-types under fatty acids?
Waxes, Triacylglycerols, glycerophospholipids, and sphingolipids
Triacylglycerols contain one long vertical _______ attached to three horizontal _____ _____
glycerol and three horizontal fatty acids’s (/\/\/\/\/=O\OH)
Waxes contain one long chained _____ and one ____ _____
alcohol and one fatty acid
Glycerophospholipids contain one long vertical ______, two horizontal ____ ______, and one horizontal _____ connected to an amino alcohol
glycerol, two fatty acids, and one PO4-amino alcohol
Which fatty acids have regular shapes, saturated or unsaturated?
Saturated
_____ ______ are long, unbranched carbon chains with a carboxylic group at the end
fatty acids
Which fatty acid contains C=C bonds?
Unsaturated
What does it mean when a fatty acid is monounsaturated?
When there is only one double C=C bond.
What does it mean when a fatty acid is polyunsaturated?
When there are at least two C=C bonds
Which fatty acids can be drawn as both cis and trans isomers?
Unsaturated (think…unfinished, out of order. Saturated fatty acids have only cis and are regularly shaped, normal, cis = normal/average)
Essential fatty acids are saturated or unsaturated? Why?
Polyunsaturated. We cannot synthesize sufficient amounts of polyunsaturated fatty acids.
Saturated fatty acids fit closely together in an irregular pattern. True or false?
False; fit together in a regular pattern
Which fatty acids have higher melting points and are usually solids at room temperature? Sat or unsat?
Saturated fatty acids
In _______, the C=C bonds cause the carbon chain to bend or kink
unsaturated fatty acids
Hormone-like substances produced in cells are called _________
prostaglandins
Prostaglandins are also known as_______
eicosanoids
eicosanoids (prostaglandins) are formed from _______ acid, which is a Mono or poly unsaturated fatty acid with 20 carbon atoms?
Arachidonic; polyunsaturated
_______ differ by the substituents attached to the five carbon ring
prostaglandins
List the common functions of prostaglandins
Lowering/raising blood pressure, and stimulating the contraction/relaxation of the smooth muscle of the uterus
When tissues are injured, arachidonic acid is converted to _______ that produce inflammation and pain in the area. NSAIDS block the production of this acid.
Prostaglandins
List common NSAIDS that block the production of prostaglandins
naproxen(aleve), ibuprofen(Advil), aspirin, and nabumetone(Relafen)
Unsaturated fats such as those in fish and _____ ___ are recognized as more beneficial to health than saturated fats
vegetable oils
Which omegas do vegetables contain? Where does the first double bond occur?
Omega-6 acids, and the first double bond occurs at the 6th carbon counting from the methyl end of the carbon chain (do not start at the alcohol)
Fish have high levels of omega-___
omega-3
linolenic acid, eicosapentaneoic acid, and docosahexaenoc acid are examples of which omega?
Omega-3 acids
Linoleic acid is an example of which omega?
Omega-6 (do not confuse with omega 3 acid “linolenic”
What is the function of omega-3 fatty acids in relation to blood clots?
Omega-3’s lower the tendency of blood platelets sticking together, reducing the possibility of clots
Waxes are _______ of saturated fatty acids and long-chain ______, each containing from 14-30 carbon atoms
esters; alcohols
Fatty acids are stored as _________ in the body
triacylglycerols
_________ are esters of glycerol and fatty acids
triacylglycerols
_________ are formed when three hydroxyl groups of glycerol reacts with the carboxyl group of three fatty acids
triacylglycerols
Which fatty acid is the major form of storage for animals?
Triacylglycerols
Which two oils are monounsaturated?
olive and peanut
Corn, cottonseed, safflower, and sunflower seed oils are _______ because they contain large amounts of fatty acids with 2+ C=C bonds
polyunsaturated
____ and _____ oil are solids at room temperature because they consist mostly of saturated fatty acids
palm and coconut
Why are soft margarines and stick margarines solid instead of liquid?
They are produced by partial hydrogenation of vegetable oils
In _______ reactions, double bonds in unsaturated fatty acids react with H+ to produce c-c bonds
hydrogenation
What is the most important result from hydrogenation?
C=C becomes c-c
What happens to a small number of cis double bonds during hydrogenation?
They become trans C=C, causing a change in the structure of the fatty acids
In the body, trans fatty acids behave like ______ fatty acids and do what to cholesterol?
Saturated; raise LDL-cholesterol(good kind) and lower HDL-cholesterol (bad kind)
Hydrolysis causes triacylglycerols to do what?
Split into glycerol and three fatty acids.
What is needed for hydrolysis of triacylglycerols to occur?
A strong acid(HCL or H2SO4) or digested enzymes called lipases
What is the reaction of a fat with a strong base such as NaOh in the presence of heat called?
Saponifiation
What does saponification do?
Splits triacylglycerols into glycerol and the sodium salts of fatty acids
________ is the process of forming “soaps” (salts of fatty acids)
Saponification
Which strong base gives soaps more solidity and the ability to mold into different shapes?
NaOH
Which strong base gives softer, liquid soaps?
KOH
___________ are similar to triacylglycerols
phospholipids
How many fatty acids do glycerophospholipids contain?
two
In glycerophospholipids, two fatty acids form ____ bonds with the first and second hydroxyl groups of glycerol
ester
Glycerophospholipids contain a ______ group that forms an ester with phosphoric acid, which forms another ______ bond with an amino alcohol
hydroxyl; phosphor-ester bond
Choline, erine, and ethanolamine are _____ _____ found in glycerophospholipids
amino alcohols
______ and _____ are two types of glycerophospholipids that are abundant in brain and nerve tissues, and found in egg yolk, wheat germs, and yeast
Lecithin and cephalin
Glyco-phos have both ____ and ____ regions, allowing them to interact with the similar substances
polar and non-plar
G-phospholipids have a _____ head containing the ionized amino alcohol.
polar
_______ are the most abundant lipids in cell membranes and play an important role in cellular permeability
g-phospholipids
High and low density ______ transport cholesterol between the tissues and the liver
lipoproteins
What does a steroid nucleus consist of?
Three cyclohexane rings and one cyclopentane ring
At what positions are the two methyl groups at in a steroid nucleus?
18 and 19
What is the most abundant and important steroid in the body?
Cholesterol
Where is the double bond in cholesterol?
Between carbons 5 and 6
Where is the hydroxyl group in cholesterol?
On carbon 3
The methyl groups in cholesterol are on what carbons?
10 and 13
Which cholesterol carbon has an alkyl chain?
carbon 17
Cholesterol is obtained from which items?
Eggs, meat, and milk
Cholesterol is synthesized in the ____
liver
What is cholesterol needed for?
cell membranes, brain and nerve tissue, steroid hormones ,and vitamin D
Bile salts are synthesized in the ____ from cholesterol but are found and stored in the ______
liver; gallbladder
Do bile salts have only polar regions?
No, they have polar and non polar regions that act like soaps to make fat soluble in water
What is the function of bile salt?
Helps absorb cholesterol
What is the predominant form of cholesterol in the blood called?
Cholesteryl esters
What do lipoproteins do?
Surround non-polar lipids with polar lipids and protein for transport to cells
Are lipoproteins soluble in water? Why or why not?
Yes, because the surface consists of polar lipids
What is the function of lipoproteins?
HDL and LDL transport nonpolar lipids and cholesterol to cells and liver
Steroid hormones are produced from ______
cholesterol
The two male hormones are:
testosterone and androsterone
The two female hormones are:
Estrogen and progesterone
Adrenal corticosteroids from the adrenal glands are considered _____ ______
steroid hormones
Adrenal corticosteroids include ____ and _____
aldosterone and cortisone
Function of cortisone:
increases blood glucose level and stimulates the synthesis of glycogen in the liver
Function of aldosterone:
Regulates electrolytes and water balance by the kidneys