Chapter 25: Fatty Acid Structure and Function Flashcards
1
Q
Class of heterogenous biomolecules (includes fatty acids)
A
- Lipids
2
Q
Fatty acids are
A
- The simplest of all lipids
- Over 100 different types
3
Q
Components of complex lipids
A
- Triacylglycerols
- Glycerophospholipids
- Sphingolipids
4
Q
Fatty acids are _____ in water
A
- Insoluble
5
Q
FAs circulate in the blood bound to
A
- Albumin
6
Q
Generally, albumin is a
A
- High capacity, low specificity carrier
7
Q
FAs are _____ at physiological pH
A
- Anionic
8
Q
FAs are composed of a
A
- Hydrophilic carboxylic acid group
- Hydrophobic hydrocarbon chain
9
Q
Chains are straight and contain
A
- An even number of carbon atoms
10
Q
Many of the biologically important FAs are
A
- Unsaturated
11
Q
The arrangement of atoms about the C = C double bond in nature is _____
A
- cis
- Introduces a kink into the hydrophobic side chain
12
Q
FAs are the simplest lipids, with the general structural formula
A
- R - COOH
13
Q
Most of the C = C double bonds are in the _____ configuration
A
- cis
14
Q
Trans fats are the _____ form of FAs
A
- Unnatural
15
Q
With longer chains, the non-polar part of the molecule
A
- Outweighs polarity
- Reduces solubility in water
16
Q
Essential fatty acids need to be
A
- Found in the diet
- Body cannot make them
17
Q
The body cannot make FAs with
A
- C = C double bonds close to the methyl end
18
Q
Omega-6 FAs tend to be
A
- Easier to over consume
19
Q
Saturated fatty acids
A
- More solid at room temperature
- Highly ordered
- All bonds between carbon atoms are single
20
Q
Unsaturated fatty acids
A
- Contain -cis double bond between carbons
21
Q
Diets high in saturated fats
A
- Will cause cell membranes to be high in saturated fat
22
Q
FA composition in membranes mirrors
A
- FA composition in diet
23
Q
The -cis double bond in oleate introduces
A
- A kink
24
Q
Presence of unsaturated fats in membranes impacts
A
- The permeability barrier
25
Kinks in the cell membrane will make it
- Easier for things to break through
26
Saturated fats are more
- Organized
| - Highly ordered
27
Polyunsaturated fats contain
- More than one double bond in the fatty acid tails
28
Double bonds of polyunsaturated fats cause
- Kinks in the FA tail
| - Prevent the molecules from tightly packing together
29
Unsaturated bonds have a _____ melting temperature
- Lower
30
Essential fatty acids (the body cannot make them) include
- Omega-3
| - Omega-6
31
Omega-3 fatty acid
- Linolenic acid
| - Cardioprotective
32
Omega-6 fatty acid
- Linoleic acid processed to arachidonic acid
| - Pro-inflammatory (pro-athrogenic)
33
Cardioprotective omega-3's can be found in
- Cod liver oil
| - Fish oil
34
Animal products are high in
- Saturated fat
| - Want to avoid overconsumption of these
35
Anti-inflammatory (Omega-3) FAs are
- Cardioprotective
36
Omega-6 FAs are
- Pro-inflammatory
37
Omega-6 is also known as
- Linoleic acid
38
Omega-3 is also known as
- alpha-Linolenic acids
39
EP A and DHA are fatty acids found in
- Milk products
| - Important in brain health
40
Arachidonic acid is a precursor to
- Prostaglandin
41
Most fatty acids exist as
- Triesters of glycerol
42
Glycerol is an
- Alcohol with three carbons
| - Each carbon bears a hydroxyl/alcohol group (triacylglycerides)
43
Triacylglycerols
- Three fatty acids linked to one glycerol molecule
44
TAG's that are solid at 25 degrees C are
- Fats
| - Largely saturated fatty acids
45
TAG is produced from
- Glycerol 3 phosphate
46
Glycerol-3-phosphate originates from either
- Glycerol (kinase)
| - Dihydroxyacetone phosphate (dehydrogenase)
47
Glycerol kinase enzyme is used to
- Phosphorylate the glycerol to activate TAGs
48
Synthesis of triacylglycerol from glycerol-3-phopshate occurs via
- Phosphatidic acid
49
Phosphatidic acid is
- Intermediate in FA synthesis
| - Activates the glycerol molecule during FA synthesis
50
Functions of FAs
- Energy storage
- Insulation
- Structural
- Chemical mediators
51
Fatty acids store energy in the form of
- Adipose tissue
52
Structural importance of FAs
- FAs found in glycerolphospholipids
| - FAs found in sphingolipids
53
Chemical mediation
- Linoleic > arachidonic acid > eicosanoids
| - PGE2 (cytoprotection)
54
Prostaglandins are chemical mediators that are
- Fatty acid derivatives
| - Important in blood flow
55
Adipose tissue in humans stores
- Triacylglycerides
56
Fats store more energy (~37kj/g) than
- Carbohydrates and proteins
57
Lipases cleave
- Triacylglycerides
58
Fats stored in adipose tissue serve as
- Insulation
59
Fat serves as padding to
- Protect sensitive organs
60
FAs play a structural role as
- Constituents of membrane ingredients
61
Biological membranes exist as a
- Phospholipid bilayer
62
General molecular formula of glycerophospholipids
- R1 & R2 = Fatty acid chains
63
Phospholipids (glycerophospholipids) are found in
- Biological membranes
64
Amphipathic
- Means that molecule has a polar and a non-polar group
| - Has a water-liking and water-hating moiety
65
Polar group of phospholipid usually will be
- Charged
66
Saturated fatty acid chains are esterified to
- C1
67
Unsaturated fatty acid chains are esterified to
- C2
68
Sphingolipids predominate in the
- Nervous system
69
Fatty acids attached to a sphingosine form a
- Ceramide
70
Sphingolipids posses the amino alcohol sphingosine made from
- Palmitate and serine
71
When a saturated or unsaturated fatty acyl group is attached to the amino group of a sphingosine molecule
- A ceramide is formed
72
Sphingosine is found in
- Nerves
| - Cell membrane
73
Ceramides are derivatives of
- Sphingosines
74
Ceramides, cerebrosides, and gangliosides possess a
- Sphingosine backbone
75
Ceramides possess a sphingosine molecule attached to
- A fatty acyl group
| - They are precursors of sphingomyelin and cerebrosides
76
Cerebrosides have a monosaccharide attached at
- C1 or ceramide
77
Gangliosides have
- A polysaccharide attached
78
Sphingomyelin
- Produced upon addition of phosphotidylcholine at C1
79
Sphingolipids are degraded to
- Hydrolytic reactions of lysosomal enzymes
80
Gangliosides are
- Important cell surface markers
| - Recognized by immune cells
81
Gangliosides are made from
- Ceramides
82
Gangliosides contain sphingosine plus
- Fatty acid
| - Variable carbohydrate components
83
Defective lysosomal enzymes lead to
- Sphingolipid storage diseases
| - Sphingolipids accumulate and these diseases can be fatal at an early age
84
Sphingolipid accumulation damages
- Neural function
85
In Tay-Sachs Disease
- Lysosomal hexosaminidase A is defective
| - Gm2 accumulates
86
Hexosaminidase A is defective in
- Tay-Sachs Disease (lysosomal storage disease)
87
In lysosomal storage diseases
- Sphingolipids accumulate in the brain
| - Lead to various neurological problems
88
Prostaglandins are
- FA derivatives of arachidonic acid
| - Multiple roles
89
Prostaglandin E2 is important in
- Cytoprotection
- Protects cells in the stomach from acid
- Too much aspirin can cause GI bleeding
90
Prostacyclin is important in
- Vasodilation
- Maintaining blood flow
- Take a mini aspirin daily
91
Fatty acid nomenclature
- Numbers separated by colon (18;0)
92
The number before the colon in naming FAs signifies
- Number of carbon atoms
93
The number after the colon in naming FAs indicates
- The number of C = C double bonds
94
If double bonds are present, they are indicated (naming FAs) by
- c (cis)
- t (trans)
- Followed by a delta symbol
- Additional numbers signify position of the double bonds
95
Triacylglycerols that are liquid at 25 degrees C are
- Oils
| - Largely unsaturated fatty acids
96
Two types of eicosanoids
- Prostaglandins
| - Lleukotrienes
97
PGE2 function
- Cytoprotection
98
The remaining OH group of glycerol is linked to a
- Phosphate group
99
A polar group is attached to an amphipathic phospholipid's
- Phosphate group
100
Fatty acid derivatives function as
- Chemical mediators
101
Eicosanoids are _____ formed from _____
- Oxygenated derivatives
| - Arachidonate (C20)
102
Chemical messengers that act locally experience
- Rapid degradation
103
(Summary ) Fatty acids are
- Monocarboxylic weak acids
- Insoluble in water
- Ionized at physiological pH
104
(Summary ) Fatty acids are classified by
- Number of carbon atoms
| - Degree of unsaturation
105
(Summary) Fatty acids are important components of
- Monoacylglycerols
- Diacylglycerols
- Triacylglycerols
- Membrane glycerophospholipids and sphingolipids
