Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

LSCI 211 > Lipids/Cell Membrane > Flashcards

Lipids/Cell Membrane Flashcards

1
Q

Property of lipids

A

Heterogeneous group of compounds, share: 1. Insolubility in water based solutions. 2. Solubility in organic/non-polar solvent.s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Normal saturated fatty acids are generally more soluble in __?

A

Chloroform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

SA FA are generally less soluble in __ ?

A

Acetonitrile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

5 Biological Functions of Lipids?

A

Storage of Energy Membrane Structure Signalling Molecules Cofactors for enzymes Antioxidants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Branch 1 Classification of Lipid

A

Complex and Biologically Active Lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Difference between Complex and Biologically Active Lipids

A

Complex = FA Biologically active = NO FA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Branches of complex lipids (FA)?

A

Storage and Structural Lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Difference between storage and structural lipids?

A

Storage = non-polar Structural = polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

examples of storage (non-polar) lipids

A

Triglycerides Waxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

examples of structural (polar) lipids

A

Phospholipids Sphingolipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Examples of biologically active lipids (No FA)

A

Prostaglandins Steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define fatty acid

A

Amphipathic molecules with hydrocarbon chains containing 3 to 35 carbons plus carboxylic group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

pKa of COOH groups?

A

<5 … therefore will be fully ionized after this time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Almost all natural FA have ____

A

an even # of carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

FA can be ___

A

saturated or unsaturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are FA physical properties based on?

A

1) Length of hydrocarbon chain 2) Degree of saturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

All naturally occurring double bonds have __

A

CIS configuration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Most common FA length?

A

C14 to C18

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is interesting about the 4 carbon FA, or butanoic acid?

A

-infinitely water soluble -solubility decreases w/ increased hydrocarbon chain length.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Solubility of Lauric acid? (12 carbon FA?)

A

partially soluble to the extent of 0.06g per gram of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Fatty acids with C10 or greater form ___ at room temp

A

Waxy solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Fatty acids with C9 or lower saturates or unsaturated HC chains form ___ at room temperature?

A

Oily solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the prefix “alpha” indicate?

A

Normal or unbranched structure. i.e alpha-linolenic acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Double bonds in FA chains produce what?

A

kinks and bends

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Due to kinks and bends in unsaturated FA … this causes what?

A

1) Unsaturated FA are LESS packed VS saturated 2) LESS ordered packing = WEAKER intermolecular interactions (vanderwall forces) 3) LOWER melting points for unsaturated fatty acids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which fatty acids can humans not synthesize? Why do we need them?

A

LinoLEIC acid, Omega 6. LinoLENIC acid, Omega 3. Need them to synthesize other needed FA, such as AA, DHA, EPA and n-3 and n-6 eicosanoids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Importance of omega 3?

A

-inhibit formation of thromboxane A2 (eicosanoids) -> associated with platelet aggregation + clot formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Omega 3 FA are associated with decrease risk of what disease?

A

Coronary diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

3 major typed of omega 3 fatty acids?

A

-alpha linolenic cid (ALA) -EPA -DHA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the effective PUFA’s?

A

EPA DHA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Characteristics of Trans Fatty Acids?

A

-partially hydrogenated - trans double bond -> adapt an extended conformation -more regularly packed -higher melting points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Formation of trans fatty acids?

A

partial hydrogenation on unsaturated fatty acids + cis-double bond Isomerization to trans double bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Example of hydrogenation?

A

Peanut butter from peanut oil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Why is high sat fat (animals) and trans fat (animals/plant) bad for health?

A

-SFA increase blood cholesterol by providing proper packing domains for cholesterol. -TF do the same, due to increase rigidity around the double bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Correlation between high cholesterol and higher incidence of heart disease, why?

A

Reduced membrane Fluidity Reduced membrane Flexibility Reduced membrane protein Functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is Anandamide?

A

Signalling molecule, found in brain + chocolate and turns on same receptor as marijuana. May explain cravings for some individuals for chocolate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How are triglycerides formed?

A

-condensation reaction, where H is lost from glycerol, OH is lost from fatty acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Acylglycerides are linked by __ ?

A

ester linkages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What increases solubility of a FA? Why?

A

shorter hydrocarbon chain increases solubility, more easily interacts with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What increases melting point of a FA? Why?

A

Increased degree pf saturation. Allows for more ordered packing + more inter molecular vanderwaals forces .. . therefore melting point increases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

fatty acids found in complex lipids are responsible for what?

A

Formation of micelles in aqueous solutions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

The glycerol moiety of a TG has a centre of ?? at the second carbon atom?

A

Asymmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Triglycerides can be assembled with what?

A

Acyl transferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Triglycerides can be disassembled with what?

A

Lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Where are TGs store in animals? Plants?

A

Fat cells, and seeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the most abundant form of metabolic storage lipids?

A

Tri-acylglycerols

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Most defining characteristic of triglycerides?

A

Both plant and animal format are insoluble.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Animal triglycerides are __

A

solid at room temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Plant triglycerides are____

A

liquids (oil) at room temp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What important aspect does fat and oil differ?

A

Degree of unsaturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How can a TG be simple?

A

if all fatty acids are of the same length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

How can a TG be complex/mixed?

A

If all 3 FA are of different lengths and saturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

TG are considered what compared to sugar?

A

A light source of energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Advantage of fats over polysaccharides

A

-Acylglycerides carry more energy per carbon because they are more reduced. -FA carry less water along because they are non polar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Glucose + glycogen are

A

short term energy needs and allow for quick delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Acylglycerides are for

A

long term (months) energy needs, good storage and long delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Where are TGs digested?

A

Small intestine by pancreatic lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Monoacylglycerides are absorbed where?

A

Into intestinal cells, and are converted in TG and packaged into lipoproteins (chylomicrons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Treatment of TG with what leads to the hydrolysis of ester bond linkage?

A

Strong Acids or bases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Formation of soaps?

A

Hydrolysis w/strong acids/bases leads to fatty acid salts and glycerol (amphipathic) molecules that can be used.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How are waxes formed?

A

Condensation reaction between long FA and alcohol carbon chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Defining of property of waxes?

A

Do NOT contain glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What do waxes act as?

A

-metabolic fule -water impermeable coating

64
Q

Melting temp of waxes?

A

-60-100 degrees C HIGHER THAN TG

65
Q

Waxes are broken down with what?

A

Strong acids and bases

66
Q

What are the two structural lipids?

A

Phospholipid Sphingolipids

67
Q

2 other names for phospholipids?

A

Phosopho-acylglycerols Glycerophopholipids

68
Q

Which carbon is the head phosphate group / located on?

A

C3

69
Q

When are phosphatidic acids - charged?

A

ph 7

70
Q

What is a phophatidic acid?

A

basic unit of phospholipid made up of 1,2-diacylglyecerol and linked to phosphoric acid

71
Q

Which carbon are fatty acids linked to?

A

C1 and c2

72
Q

where is phosphoric acid linked to?

A

3rd hydroxyl glycerol

73
Q

what kind of bond attaches phosphoric acid and glycerol?

A

Phospho-ester bond

74
Q

Fatty acids attached the C1 of carbon are usually?

A

Saturated

75
Q

Fatty acids attached to C2 of carbon are often?

A

Unsaturated

76
Q

Alcohol based compounds linked to phophatidic acids are known as?

A

head groups

77
Q

Glycerol 3-phosphate is ___

A

the CHIRAL backbone of phospholipids

78
Q

When can the C3 phosphate be considered phosphatidic acid? What will the net charge be?

A

when the head group = H -1

79
Q

Which Head groups create a neutral phospholipid?

A

Ethanolamine Choline

80
Q

Which her groups createa negative phospholipid?

A

-Serine -Glycerol -myo-Inositiol 4,5-bisphosphate -Phosphatidyl-glycerol

81
Q

Diacylglycerol + Phosphoric Acid =

A

Glyecrophospholipid

82
Q

what determines surface properties of glycerophospholipids?

A

Properties of head groups!

83
Q

Different organisms have different ____ lipid head group compositions

A

Membrane

84
Q

Different tissues have different ____ lipid head group compositions

A

Membrane

85
Q

Major component of most eukaryotic cell membranes?

A

Phosphatidylcholine Net Charge of zero Head group = choline

86
Q

Why can’t many prokaryotes synthesize phosphatidylcholine?

A

because it does not appear within their membranes

87
Q

How are glycerophospholipids similar? different

A

Similar: all are amphiphatic with charged head groups BUT they will differ in net charge!

88
Q

Structure of Sphingosine

A

Sphingosine (C3 + backbone) attached to a fatty acid (C2) and a head group (C1)

89
Q

Phophocholine at attached where on sphingolipid, what is the bond called?

A

C1 Phosphoester bond

90
Q

Sphingomyelin, has what C1 group?

A

Phosphocholine

91
Q

neutral Glycolipids -> glucosylcerebroside has what C1 group?

A

Glucose

92
Q

Glucose is attached where on sphingolipid, what s the bond called?

A

Glycosidic bond

93
Q

Lactosylceramid (globoside), has what c1 group?

A

Di-tri or tetrasaccharide

94
Q

Ganglioside GM2 has what c1 group?

A

Complex oligosaccharide

95
Q

What is the backbone of sphingolipids?

A

Long-chain amino alcohol -> sphingosine

96
Q

What kind of linkage joins FA to sphingosine on C2?

A

Amide linkage

97
Q

Joining of one FA via amide linkage on C2 to sphingosine gives what? What is it structurally similar to?

A

Ceramide, structurally similar to a diacylglycerol

98
Q

Addition of phosphoric choline group =

A

sphingosine -> sphingomyelin

99
Q

Addition of sugar group =

A

sphingosine -> cerebroside

100
Q

Addition of combination of sugars (oligosaccharides)=

A

sphingosine -> ganglioside

101
Q

cerebrosides and gangliosides are largely doubt where? What is the downside of this?

A

-outer face of plasma membranes, consequently detectable by the immune system.

102
Q

Glycosphingolipids blood groups are determined by what?

A

-type of sugars located on the head groups

103
Q

Structure of sugar on head group of glycosphingolipids are determined by what?

A

expression of specific glyocosyltransferases

104
Q

individuals with inactive glycosyltransferase will have the :

A

O antigen

105
Q

Individuals with glycosyltransferase that transfers N-acetylgalactosamine will have:

A

A blood group

106
Q

Individuals with the glycosyltransferase that transfers a galactose group will have the:

A

B blood group

107
Q

what do all blood groups have in common?

A

Galactose Fucose N-acetly-glucosamine Red Blood cell

108
Q

What do biologically active lipids not contain? How can they be generated?

A

Fatty acids or glycerol back bone. Can become generated by fatty acids

109
Q

What is the major physiologic role of BAL?

A

-recruiting the activities of proteins and receptors

110
Q

Importance of steroids?

A

-metabolically for digestions, bile salts. -hormones (sex hormones)

111
Q

What are the major classes of BAL?

A

Prostaglandins Sterols

112
Q

How are prostaglandins generated?

A

Modification of fatty acids

113
Q

how are sterols generated?

A

From two carbon acids (acetate) and from modification of other sterols.

114
Q

How do cells turnover their lipids in lysosomes?

A

By cleavage of ester linkages by 4 phospholipase

115
Q

Name the 4 phospholipase

A

A1 A2 C D

116
Q

Phospholipase A1 cleaves what bond?

A

C1 ester linked FA

117
Q

Phospholipase A2 cleaves what bond?

A

C2 ester linked FA

118
Q

Phospholipase C cleaves what bond?

A

C3 phophoester linked phosphoric acid

119
Q

Phospholipase D cleaves what bond?

A

Phosphoeter linked X or head groups

120
Q

What are the two classes of Phospholipases?

A

-Phospholipid-specific lipase -Broad substrate phosphoplipases

121
Q

Which specific phospholipase hydrolysis is important in Protein Kinase C pathway ?

A

Phosphatidylinosital 4,5-bisphosphate

122
Q

describe the sequence that occurs with protein kinase C pathway

A

All driven by kinases .. Signal will come into receptor, binds to receptor and will activate lipase. this lipase will then continue to cleave head group + generate lipids.

123
Q

PMA is a dietster of what and what does it promote?

A

Phorbol, a tumor promotor by activating the signal transduction enzyme of protein kinase C

124
Q

What are paracrine lipid hormones?

A

hormones which are present in small amount and play vital roles as singling molecules between nearby cells.

125
Q

Enzymatic oxidation of arachidonic acid yields:

A

-Prostaglandins -Thromboxanes -Leukotrienes (PLT)

126
Q

What does NSAID stand for, what do they do?

A

Non steroidal Anti Inflammatory drugs (aspirin, ibuprofen) Block cycloxygenase and prevents production of PLT

127
Q

What do prostaglandins do?

A

Involved in inflammation + fever smooth muscle contraction in uterus

128
Q

What do thromboxanes do?

A

Vasoconstrictor and facilitates platelet aggregation (heart disease link?)

129
Q

What do Leukotrienes do?

A

Smooth muscle contraction in the lungs

130
Q

What are the building blocks of cholesterol?

A

-Vitamins (KEA) -Cartenoids -Plant Hormones (Abscisic, Gibborelic acid) -Rubber -Phytol Chain of Chlorophyll -Quinone Electron Carriers (Ubiquinone, Plastiquinone) -Isoprene

131
Q

What does Cholesterol give rise to?

A

Steroid Hormones Bile Acids Vitamin D

132
Q

What steroid hormones does cholesterol give rise to?

A

-Testosterone -estradiol -Cortisol -Aldosterone (TECA)

133
Q

Properties of sterol?

A

-Steroid nucleus: 4 fused rings -Hydroxyl group (polar head) on the A-ring. -Various non-polar side chains. -Steroid nucleus is almost planar.

134
Q

Describe Cholesterol

A

-steroid w/ hydrophobic tail in two parts: -rigid planar rings and flexible/branched hydrocarbon chain.

135
Q

What is the hydrophilic part of cholesterol?

A

Hydroxyl (head) group.

136
Q

Since cholesterol is an amphipathic molecule, what is its function>=?

A

Often a structural lipid within the cell membrane.

137
Q

What does the structure of cholesterol prevent?

A

Promotes tight packing of UPPER ends of the fatty acids hydrocarbon tails, therefore INCREASING the melting point of the lipid bilayer.

138
Q

Why is cholesterol known as the fluidity buffer?

A

because is will increase the melting point of the lipid bilayer due to its dense packing up upper ends of FA hydrocarbon tails

139
Q

The fluidity buffer does what?

A

decreases the sharpness of the Gel to liquid crystalline transition.

140
Q

The rigid structure of cholesterol favours what?

A

-interaction w/ saturated or tran fat unsaturated lipid … these fats enhance cholesterol accumulation within the membrane!!

141
Q

Describe Lipid Micelles

A

-small spherical structures -water is EXCLUDED from interior -Free FA and some detergents assume this conformation because the size of the head to tail ratio is MORE than 1

142
Q

Describe lipid bilayer

A

-Sheet like structure with two monolayer -water is EXCLUDED from interior -Phosphoacylglyceride + Sphingolipids favour this lipid aggregates because the size of the head to tail ration is EQUAL to 1

143
Q

describe Liposomes

A

-Hollow sphere of lipid bilayer folded back onto itself -Aggregates ENCLOSE water, thus act as barriers between two environments.

144
Q

How does cholesterol maintain integrity of membrane as temp increases?

A

As temp increase, FA moves too much, rigidity of cholesterol helps keep them in place and maintain integrity.

145
Q

How does cholesterol maintain integrity of membrane as temp decreases?

A

As temp decreases, FA will have tendency to crystallize. Cholesterol blocks the intermolecular interaction (vanderwall forces) between adjacent FA and maintains integrity.

146
Q

If we decrease membrane temp, what do we add?

A

Increase amount of Unsaturated fat. unsaturated fat has a lower melting point, therefore counteracting the crystallization effect within the membrane.

147
Q

If we increase membrane temp, what do we add?

A

increase amount of saturated fat. Saturated fat has a higher melting point, therefore counteracting the liquid effect.

148
Q

What can we find within the cell membrane?

A

Glycolipids Peripheral Proteins Integral Proteins Glycoproteins Cholesterol Phospholipids

149
Q

Cell membrane is permeable to: (WHN)

A

hydrophobic molecules neutral gases water

150
Q

Cell membrane is impermeable to: (PLC)

A

Proteins Large Molecules Charged Ions

151
Q

Lipids can diffuse through the cell membrane ..

A

LATERALLY only

152
Q

Describe Uncatalyzed membrane diffusion

A

-Lipids only FAST! (~1um/s)

153
Q

Describe Uncatalyzed transbilayer (Flip Flop)

A

-Very Slow No Lipids (t1/2 in days0

154
Q

List the 3 kinds of catalyzed trans membrane translocations

A

Flippase Floppies Scramblase

155
Q

What is required for Flippase? Where does the phospholipid flip?

A

-Ptype ATPase Moves from outside to INSIDE

156
Q

What is required for Floppies? Where does the phospholipid flip?

A

-ABC transporter moves from inside to OUTSIDE

157
Q

What is required for Scramblase? Where does the phospholipid flip?

A

Will flip in both directions to establish equilibrium.

LSCI 211 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions