Chapter 6: Lipids Flashcards
1
Q
most widely occuring types of lipids
A
- fats
- oils
2
Q
thick layers of fat help __ polar bears against the effect of low temperatures
A
insulate
3
Q
where is the characterization of lipids based on
A
solubility characteristics
4
Q
oranic compound found in living organisms that is insoluble (or only sparingly soluble) in water but soluble in nonpolar solvents
A
lipids
5
Q
where is the word lipd from
A
Greek lipos = fat or lard
6
Q
where is lipids soluble
A
nonpolar organic solvents
7
Q
Four main types of lipids
A
- fatty acids
- glycerides
- nonglyceride lipids
- complex lipids
8
Q
fatty acids
A
- saturated
- unsaturated
9
Q
glycerides
A
- neutral glycerides
- phosphoglycerides
10
Q
nonglyceride lipids
A
- sphingolipids
- steroids
- waxes
11
Q
sphingolipids
A
- sphingomyelins
- glycolipids
12
Q
complex lipids
A
lipoproteins
13
Q
are found in many types of lipids
A
fatty acids
14
Q
Biological functions of lipids
A
- energy source
- cell membrane structural components
- hormones
- vitamins and vitamin absorption
- protection
- insulation
15
Q
energy source
A
triacylglycerols
16
Q
when oxidized, how many kilocalories of energy do lipids release
A
9 kilocalories
17
Q
kilocalories of energy released by carbohydrate
A
4 kcal
18
Q
fat cells
A
adipocytes
19
Q
make up the basic structure of all cell membranes
A
- phospholgycerides
- sphingolipids
- steroids
20
Q
- play an important role in clotting of blood and in structure of a membrane
- allow transport of enzymes and is a major component of membrane
A
Phosphoglycerides
21
Q
- enriched in the Central Nervous System (CNS) and display multiple biological functions
- participate in tissue development, cell recognition and adhesion, and act as receptors for toxins
A
Sphingolipids
22
Q
- dominant sphingolipid in membranes of mammalian cells
- specifically enriched in the plasma membrane, the endocytic recycling compartment, and the trans Golgi network
A
Sphingomyelin (SM)
23
Q
- reduce the fluidity of the cell membrane
- function as signaling molecules within the cell
A
Steroids
24
Q
combination of phospholipids and proteins that reduces surface tension in the alveoli of the lungs
A
pulmonary surfactant
25
small, thin-walled air sacs in the lungs
alveoli
26
what do pulmonary surfactants allow
- efficient gas exchange across membranes
- oxygen and carbon dioxide can easily diffuse
27
pulmonary surfactant is not produced until early in the __ __ of pregnancy
6th month
28
what do premature babies born before they have begun secretion of natural surfactant suffer from
respiratory distress syndrome (RDS)
29
administered directly into the trachea of babies with respiratory distress syndrome (RDS)
artificial surfactant
30
critical chemical messengers that allow tissues of the body to communcate with each other
steroid hormones
31
exert strong biological effects on both the cells that produce them and other cells of the body
prostaglandins
32
can reduce pain, fever and other types of inflammation by inhibiting the COX enzymes
Non-steroidal anti-inflammatory drugs (NSAIDs)
33
precursor of prostaglandins
arachidonic acid
34
physiological stimuli
COX1
35
infection, injury
COX2
36
COX1
protective prostaglandins
37
COX2
inflammatory prostaglandins
38
protective prostaglandins
- stomach mucosa
- platelet stickiness
39
inflammatory prostaglandins
- pain
- fever
- inflammation
40
lipid-soluble vitamins
- A
- D
- E
- K
41
- important for normal vision, the immune system, reproduction, and growth and development
- helps your heart, lungs, and other organs work properly
Vitamin A
42
- essential for bone strength and may be good for supporting the immune system and other functions
Vitamin D
43
- main role is to act as an antioxidant, scavenging loose electrons—so-called “free radicals”—that can damage cells
- enhances immune function and prevents clots from forming in heart arteries
Vitamin E
44
- group of vitamins that the body needs for blood clotting, helping wounds to heal
- may help keep bones healthy
Vitamin K
45
fat serve as a __ __, or protective layer for the vital organs
shock absorber
46
percent of body fat reserved for protection
4%
47
hormones
- steroid hormones
- eicosanoids
48
- signaling molecules that play a unique role in innate immune responses
- allow the innate immune cells to respond rapidly to bacterial invaders
Eicosanoids
49
serves to insulate the body from extremes of cold temperatures
subcutaneous fat
50
Two categories of lipids based on hydrolysis
1. Saponifiable lipids
2. Nonsaponifiable lipids
51
hydrolysis reaction that occurs in basic solution
saponification reaction
52
saponifialbe lipids
1. triacylglycerols
2. phospholipids
3. sphingoglycolipids
4. biological waxes
53
nonsaponifiable lipids
1. cholesterol
2. steroid hormones
3. bile acids
4. eicosanoids
54
a lipid is any substance that is __ in water and __ in nonpolar solvents
- insoluble (water)
- soluble (nonpolar solvents)
55
the saponification/nonsaponification classification system for lipids is based on
lipid behavior in basic solution
56
- long-chain monocarboxylic acids
- generally contain an even number of carbon atoms as a consequence for their biosynthesis
- rarely found in nature but rather part of more complex lipid structure
fatty acids
57
one that contains at least one carbon-to-carbon double bond
unsaturated fatty acid
58
18-carbon unsaturated fatty acid
oleic acid
59
the double bonds found in almost all naturally occuring lipids is __ __
cis-configuration
60
cis-configuration puts a rigid __ __ in the chain
30° bend
61
fatty acid with a carbon chain with one carbon-carbon double bond present
monounsaturated fatty acid (MUFA)
62
fatty acid with a carbon chain in which two or more carbon-carbon double bond
polyunsaturated fatty acid (PUFA)
63
up to __ double bonds are found in biochemically important PUFAs
six
64
MUFAs are usually __ acids and first two additional double bonds in PUFAs are generally at __ and __ locations
- Δ9
- Δ12
- Δ15
65
PUFA of arachidonic acid
20:4(Δ5,8,11,14)
66
exist when double-bond position is specified relative to the methyl (noncarboxyl) end of the fatty acid carbon chain
families of unsaturated fatty acids
67
families of unsaturated fatty acids exist when double-bond position is specified relative to the __ __ of fatty acid carbon chain
methyl (noncarboxyl) end
68
an unsaturated fatty acid with its endmost double bond three atoms away from methyl end
Omega-3 FA
69
unsaturated fatty acid with its endmost double bond six carbon atoms away from its methyl end
Omega-6 FA
70
statement regarding fatty acids
rarely found in free state in nature
71
example of members of pair polyunsaturated fatty acids
- 18:2 acid
- 18:3 acid
72
example of omega-6 fatty acid
CH3 -- (CH2)4 -- CH==CH -- (CH2)8 -- COOH
73
double bond present in monounsaturated fatty acid almost always in
cis-configuration
