Lipids Flashcards
1
Q
Why do fatty acids provide a rich source of stored chemical energy for cells?
A
Because they are highly reduced
2
Q
What are some functions of lipids?
A
Storage of energy
Structure and function of cell membrane
Signalling
3
Q
Example of lipids in cellular membranes
A
Glycerophospholipids
Sterols
4
Q
Example of cellular messenger lipids
A
Hormones
Electron carriers
Pigments
5
Q
4 most common types of membrane lipids
A
Fatty acids
Glycerides
Non glyceride lipids
Complex lipids
6
Q
2 types of fatty acids
A
Saturated
Unsaturated
7
Q
2 types of glycerides
A
Phosphoglycerides
Neutralglycerides
8
Q
3 non glyceride lipids
A
Sphingolipids
Steroids
Wax
9
Q
2 types of complex lipids
A
Lipoproteins
Glycolipids
10
Q
2 classifications of fatty acid lipids
A
Storage lipids
Membrane lipids
11
Q
3 type of lipids that don’t contain fatty acids
A
Cholesterol
Vitamins
Pigments
12
Q
How do many carbons do fatty acids typically contain?
A
Between 4-36
13
Q
Which type of fatty acids have one double bond?
A
Mono saturated
14
Q
Which type of fatty acids typically have more than one double bond?
A
Polysaturated
15
Q
Which type of fatty acids have no double bonds?
A
Saturated
16
Q
Why is it called omega 3 fatty acids?
A
Because the double bond is at the 3rd carbon
17
Q
What is the omega classification used for?
A
Locating the double bond
18
Q
How do you read C14:0 ?
A
C14= 14 carbons
0= no double bonds
19
Q
Most common unsaturated fatty acid
A
Oleic acid (9-octadecacenoic)
20
Q
What does the precense of cis double bonds increase in fatty acids?
A
The fluidity
21
Q
What kinds of fatty acids cause a bend?
A
The cis
22
Q
Which type of fatty acids are present in our bodies?
A
Cis
23
Q
How is the solubility in water of fatty acids?
A
Poor
24
Q
What increases the solubility of fatty acids in water?
A
Increased chain length
25
What decreases the solubility of fatty acids?
Decreasing the number of double bonds
26
What is the carboxylic acid group at neutral pH?
Polar and ionized
27
What are saturated fatty acids at room temperature?
Solid
28
What are unsaturated fatty acids at room temperature?
Liquid
29
What are trans saturated fatty acids like and why?
Unsaturated fatty acids because the chain is straight due to the trans double bond
30
How are the saturated fatty acids packed?
In an orderly way
31
How are unsaturated cis fatty acids packed?
In an less orderly way due to the kink on the chain
32
Why type of fatty acids does it takes least thermal energy to disrupt?
Unsaturated fatty acids
33
When does solubility decrease?
When chain length increases
34
When does the melting point decrease?
When the chainlength decreases
When the number of double bonds increases
35
What happens to food when the double bond of unsaturated fatty acids are cleaved oxidatively to aldehydes and carboxylic acid
It becomes rancid
36
What is partial hydrogenation?
Profess that converts many of the cis double bonds in the fatty acid to single bonds and trans fatty acid bonds
37
Practical application of partial hydrogenation
Improve shelf life
Increase stability
Increase melting temperature
38
Why is it called partial hydrogenation?
Some cis bonds are not fully hydrogenated so they become trans fatty acids where some are fully hydrogenated into single bonds
39
What are LDL?
Low density lipoproteins
40
What are HDL?
High density lipoprotein
41
What negative effects do trans fatty acids have?
Raise the level of triaclyglycerols in the blood
Raise level of LDL (bad) cholesterol in the blood
Lower levels of HDL (good) cholesterol
Increases the body’s inflammatory response
42
Which conformation is most common in fatty acids?
Cis
43
What fatty acids are essential to human health but not produced in the body?
Unsaturated fatty acids
44
Which is the most common storage fat?
Triglyceride
45
What does triglyceride contain?
3 glycerol
3 fatty acids
46
Do fatty acids metabolism yield more carbon energy per carbon?
Yes because they are more reduce
47
Why do fatty acids carry less water per gram?
Because they are nonpolar
48
6 lipid droplet functions
Protection against lipotoxicity
Energy and redox homeostasis
Fatty acid channeling to mitochondria
ER and membrane homeostasis
Regulation of autophagy
Lipid mediator production
Protection against lipotoxicity
49
What are the properties of membrane lipids?
Amphiphatic
Hydrophobic regions
Hydrophilic regions
50
What do glycolipids contain as the polar end?
Sugars
51
What are glycerophospholipids the derivative of?
Phosphatidic acid
52
Which is the most simple phospholipid?
Phosphatidic
53
Where are structural lipid degraded?
In the lysosome
54
What kind of lipids are gangliosides?
Glycolipids
55
What happens when lipids are cut down?
They are recycled
56
What is lysosomal storage disorder?
When you’re missing an enzyme that cuts down lipids (gangliosides) or it is not working the lipids in the lysosome are not cut down and recycled properly causing a build-up of lipids in the lysosomes
57
What contributes to neurodegeneration ?
Inhibition of lysosome membrane recycling as it causes accumulation of gangliosides
58
What is cholesterol blades on?
Steroid nucleus
59
General structure of cholesterol
4 hydrophobic rings (steroid nucleus)
Polar head (OH)
Alkyl side chsin
60
What is a steroid nucleus?
Four fused rings
61
General structure of sterols ?
Steroid nucleus
Hydroxyl group (polar head) in the a-ring
Various non polar side chains
62
What do steroid hormones do?
Regulate gene expression
63
What kind of structure does bile acid have?
Sterol
64
Where is cholesterol vey important and why?
In the membrane
Because it.creates fluidity
65
Do we synthesize ass the cholesterol we need?
No we need to obtain it from food
66
Hare steroid hormones more polar than cholesterol?
Yes
67
Where do steroid hormones oxidise from?
Sterols
68
In lipid storage/Droplets what is form of cholesterol are present?
Cholesteryl ester
69
What is found in lipids droplets?
Cholesteryl ethers
Triaglucerol
70
What is VLDL?
Very low density lipoprotein
71
3 types og lipoprotein particles
HDL, LDL AND VLDL
72
What kind of linkage is are the two actors chains attached to glycerol with in ether lipids?
Ether linkage
73
What proteins compose the lipid protein?
Apoprotein
74
What are the functions of membranes?
It defined the boundaries of the cell
Allow import and export
Retain metabolites and ions within the cell
Signal relieving and sending
Provide compartmentalisation within the cell
Produce and transmit nerve signal
Store energy as a proton gradient
Support synthesis of ATP
75
Is the distribution of lipids in membranes symmetric?
No
76
What kind of molecules are membrane lipids?
Small amphipathic molecules
77
What kind of interactions are between lipids in membranes?
Noncovalent
78
What are micelles?
Spherical structures containing amphipathic molecules arranged with hydrophobic regions in the interior and hydrophilic head groups on the exterior
79
When are micelle formation favoured?
When the cross-sectional area of the head group is greater than that of the acts side chains
80
3 type of lipid formation
Belayer
Micelle
Vesicle (liposome)
81
When does vesicle formation happen?
Spontaneously when a belayer sheet folds back on itself to form a hollow sphere
82
What kind of movement does the fluid mosaic model allow for?
Lateral but not rotation
83
Is transverse diffusion of lipids slow or rapid?
Very slow
84
Is lateral diffusion of lipids rapid or slow?
Rapid
85
What are eicosanoid?
Paracrine hormones, act in the area of where they are produced
86
How many carbons does arachidonic acid have?
20 carbon acid
87
What is linoleum acid?
An essential fatty acid (we can not synthesise it)
88
What are sterols?
Structural lipids present in the membranes of most eukaryotic cells
89
What kind of lipids are cholesterol?
Sterol
90
What do steroid hormones regulate?
Gene expression
91
Can we synthesise cholesterol?
Yes (mainly in liver)
92
Which vitamins are hormone precursors?
A and D
93
What does vitamin D deficiency leads to?
Defective bone formation
Disease Rickets
94
What is lipolysis?
Breaking of ester bonds making triglyceride into glycerol and fatty acids
95
What is lipogenesis?
The formation of ester bonds making glycerol and fatty acids combine to triglyceride
96
How many carbons in glycerol
3
97
How are unsaturated fatty acids named?
Carbons are numbered from the omega (methyl) end and then they are named accordingly: "omega 3"
