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Flashcards in 2.05 Lipids Deck (100)
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Groups of compounds related by certain physical properties

Lipids

1

Physical (rather than chemical) properties common to all lipids

Insoluble in water
Soluble in nonpolar solvents

2

Generally compartmentalized to protect themselves from watery environment of cells

Lipids

4

Functions of lipids

Major source of energy (triglycerides)
Provide hydrophobic barrier in cell membrane (phospholipid)
Coenzyme and regulators
Hormones (cholesterol, steroids)
Mediators of inflammation (prostaglandin, leukotriene)
Electrical insulators in myelinated nerves (sphingomyelin)

5

Classification of lipids

Simple
Complex
Derived Lipids

6

Fats/oils: esters of FA with alcohol
Waxes: esters of FA with higher MW monohydric alcohol

simple lipids

7

Phospholipids: FA + alochol + phosphoric acid residue
Glycolipids: FA + spingosine + carbohydrate
Sulfolipids, amino lipids,

complex lipids

8

Hormones, Ketone bodies, glycerol

Derived lipids

9

Long chains of carboxylic acids
Classified according to degree of saturation

Fatty acids

10

No double bond

Saturated FA

11

One double bond

Monounsaturated FA

12

More than one double bonds

Polysaturated FA

13

Most frequently used system
Unsystematic, conscise and often unambiguous

Trivial nomenclature

14

Mainly named after number of hydrocarbons
Technically clear
IUPAC

Systematic names

15

Double-bond indicated by delta x

Delta x nomenclature

16

Double bond located from the xth carbon-carbon bond starting from the terminal methyl carbon towards the carbonyl carbon

n-x Nomenclature

17

In the from C:D where C is the number of carbon atoms in the FA, and D is the number of double bonds

Lipid numbers

18

16:0

Palmitic acid

19

18:2; 9,12

Linoleic acid

20

18:3; 9,12,15

Linolenic acid

21

20:4; 5,8,11,14

Arachidonic acid

22

omega 3

Linolenic acid

23

omega 6

Linoleic acid

24

Linoleic acid and Linolenic acid are considered _____

Essential FA

25

Most common FA

Palmitic acid

26

Eicosanoids are derived

Arachidonic acid

27

Major end product of CHO fermentation by rumen organisms

Acetic acid

28

In certain fats in small amounts
An end product of CHO fermentation by rumen organisms

Butyric, valeric, caproic

29

Spermaceti, cinnamon, palm kernel, coconut oils, laurel, butter

Lauric acid

30

Nutmeg, palm kernel, coconut oils, myrtles, butter

Myristic acid

31

Common in all animal and plant fats

Palmitic acid, stearic acid

32

Geometric isomerism of unsaturated fatty acids

Cis
Trans fatty acid

33

Hydrocarbons are on the same side of the double bond

Cis FA

34

Hydrocarbons are on the opposite side of the double bond

trans

35

Being more liquid at room temperature

Fluidity

36

Temperature where solids change to liquids

Melting point

37

Relationship of fluidity and melting point

Inversely proportional

38

Increase chain length: fluidity ___, MP ____

Decreases; Increases

39

Decrease saturation; fluidity ____, MP ____

Increases; Decreases

40

Precursor of arachidonic acid

Linoleic acid

41

Deficiency of this essential FA results in decreased vision and altered learning behavior

Linolenic acid

42

Lowers thromboxane production
Reduced tendency of platelets to aggreagate

Omega fatty acids

43

Esters of the trihydric alcohol glycerol and fatty acids
Main storage forms of energy in the body

Triglycerides

44

Extremely potent compounds that elicit a wide range of responses, both physiologic and pathologic

Eicosanoids

45

Comprise prostaglandins, thromboxanes, leukotrienes and lipoxins

Eicosanoids

46

Dietary precursor of the eicosanoids

Linolenic acid

47

Immediate precursor of the eicosanoids
Released from membrane lipids by phospholipase A2

Arachidonic acid

48

Synthesized in platelets and cause vasocontriction and platelet aggregation

Thromboxane (TXA2)

49

Produced by blood vessel walls and are potent inhibitors of platelet aggregation

Prostacyclin (PGI2)

50

Mixture of leukotrienes C4, D4, E4
Potent constrictors of broncial airway musculature

Slow-reacting substances of anaphylaxis (SRS-A)

51

From arachidonic acid -> cyclooxygenase pathway

Prostaglandin
Thromboxane

52

From arachidonic acid -> lipoxygenase pathway

Leukotrienes

53

Amphipathic compounds composed of alcohol, diacylglycerol or sphingosine, phosphodiester bond

Phospholipid

54

Predominant lipids of cell membranes
Degraded by phospholipases

Phospholipid

55

Most abundant phospholipid
Found in cell membranes

Phosphatidylcholine
Lecithin

56

Ehanolamine replaces choline
Also found in cell membranes

Phosphatidylethanolamine
Cephalin

57

Serine replaces choline
Found in most tissues, cell membrane
Plays a role in apoptosis

Phosphatidylserine

58

Active lipid component of lung surfactant
Inadequate levels lead to Newborn Respiratory Distress Syndrome
Decreases the surface tension of alveoli, enabling them to expand again

Dipalmitoylphosphatidylcholine
Dipalmitoyllecithin
DPPC

59

3 phospholipids in cell membrane

Phosphatidylcholine
Phosphatidylethanolamine
Phosphatidylserine

60

Reservoir for arachidonic acid in the cell membranes
Source of 2nd messengers

Phospatidylinositol 4,5 BP

61

Degraded by phospholipase C to produce inositol triphosphate and diacylglycerol
IP3 and DAG mediate the release of intracellular calcium and activation of protein kinase C

Phospatidylinositol 4,5 bisphosphate

62

2 molecules of phosphatidic acid esterified through their phosphate groups to an additional molecule of glycerol
Found only in the mitochondria and is essential for its proper function
Only non-protein substance that is considered as antigen

Cardiolipin

63

Part of the glycocalyx located on the outer layer of the cell membrane and functions in cell recognition and cell adhesion
Found in high concentrations in nervous tissue

Glycolipid

64

Sphingosine + fatty acid

Ceramide

65

Ceramide + glucose/galactose

Cerebroside

66

Ceramide + oligosaccharide

Globoside

67

Ceramide + N-acetylneuramic acid

Ganglioside

68

Ceramide + sulfated galactose

Sulfatide

69

Major glycoshingolipid of the brain and the nervous tissue
Can be converted to sulfogalatosylceramide

Galactosylceramide

70

Present in nervous tissue
Parts of receptors

Ganglioside

71

Receptor in the human intestine of cholera toxin

GM1

72

Only significant sphingophospholipid in humans where it is an important constituent of the myelin sheath of nerves

Sphingomyelin

73

Similar cyclic nucleus resembling phenanthrene to which cyclopentane ring is attached (4 rings)
Methyl side chains at position 10, 13, and a side chain usually at position 17

Steroid

74

More common and more stable form

chair form

75

Best known steroid
Very hydrophobic compound composed of 4 fused hydrocarbon rings and 8-membered branched hydrocarbon chain

Cholesterol

76

Cholesterol has a single hydroxyl group located at _____ of the __ ring to which a FA can be attached to form _____

C-3; A; Cholesteryl ester

77

Cholesterol is the precursor of ______

Cell membrane
Vitamin D
Adrenocortical Hormones, Sex Hormones
Bile Acids

78

Active form of vitamin D

1,25-dihydroxycholecalciferol

79

Two primary bile acids

Cholic acid, chenodeoxycholic acid

80

Peroxidation of lipids exposed to oxygen produces ____
Highly-charged, unstable oxygen molecules with an unpaired electron

Oxygen free radicals

81

Peroxidation of lipids is triggered by _____

Existing free radical
Light
Metal ions

82

Peroxidation of lipids is catalyzed by _____

Heme compounds
Leukotrienes

83

Oxygen free radicals are counteracted by ____

Anti-oxidants

84

Auto-oxidation

Peroxidation

85

Types of Antioxidants

Preventive antioxidants
Chain-breaking antioxidants

86

Include catalase and glutathione peroxidase that reacts with ROOH, selenium, chelators

Preventive antioxidants

87

Activates glutathione peroxidase

Selenium

88

Chelators of metal ions

EDTA and DTPA

89

Include superoxide dismutase (SOD) and vitamin E

Chain-breaking antioxidant

90

Partly hydrophilic, party hydrophobic

Amphipathic lipids

91

Examples of amphipathic lipids

FA, phospholipids, sphingolipids, bile salts

92

Nomenclature
The carbon atoms are numbered, beginning with the _____ as carbon 1

Carbonyl carbon

93

Two classes of phospholipids

Glycerophospholipids (those that contain glycerol)
Sphingophospholipids (those that contain sphingosine)

94

Simplest phosphoglyceride and the precursor of the other members of the glycerophospholipids

Phosphatidic acid

95

A long chain fatty acid is attached to the amino group of sphingosine though an amide linkage, producing a ______

Ceramide

96

Alcohol group at C-1 of sphingosine is esterified to phosphorylcholine, producing ______

Sphingomyelin

97

Structural component of all cell membranes, modulating their fluidity and, in specialized tissues, precursor of hormones

Cholesterol

98

Ring A of cholesterol has a hydroxyl group at ___

Carbon-3

99

Branched hydrocarbon chain of cholesterol is attached to ____ of the D ring

Carbon-17

100

Ring B has a double bond between ____

C-5 and C-6