LIPIDS Flashcards
1
Q
Collective term for fixed oil, fats and waxes.
A
LIPIDS
2
Q
are biomolecules that are insoluble in water but readily soluble in organic solvents, such as chloroform or acetone
A
LIPIDS
3
Q
lipids are classified by their ____
A
miscibility/immiscibility in water
4
Q
lipids do not have any common ____
A
building blocks
5
Q
Lipids are not defined by a particular functional group, thus they have a ____ of structures and functions.
A
variety
6
Q
Lipids contain many ____ C—C and C—H bonds and few polar bonds resulting in their water insolubility.
A
nonpolar
7
Q
Are heterogeneous group of compounds (fats, oils, steroids, waxes and related compounds), that are related more by their physical than by their chemical properties.
A
Lipids
8
Q
Properties of Lipids
____ to touch, leaves a permanent oily stain on paper;
A
greasy
9
Q
Properties of Lipids
____ than water
A
lighter
10
Q
Properties of Lipids
When ____, colorless with bland odor and taste;
A
pure
11
Q
Properties of Lipids
____ color in fat is due to carotene
A
yellow
12
Q
Properties of Lipids
Yellow color in fat is due to
A
carotene
provitamin A
13
Q
Properties of Lipids
When ____ strongly, undergoes decomposition forming acrid flammable vapors
A
heated
14
Q
Properties of Lipids
whenignited, they burn with a ____ flame.
A
sooty
15
Q
- test conducted for lipids
- leaves a permament oily stain on paper
A
grease spot test
16
Q
acrid flammable vapors is called
A
acrolein (propenal)
17
Q
egg yolk contains, an emulsifying agent
A
lecitin
18
Q
lipid soluble vitamins
A
A D E K
19
Q
Major Roles of Biological Lipids
They serve as ____ of biological membranes.
A
structural components
20
Q
Major Roles of Biological Lipids
They provide energy reserves, predominantly in the form of ____.
A
triacylglycerols
21
Q
Major Roles of Biological Lipids
Both lipids and lipid derivatives serve as ____.
A
chemical messengers
22
Q
Major Roles of Biological Lipids
____ aid in lipid solubilization.
A
lipophilic bile acids
23
Q
Biomedical Importance
Fats are stored in ____
A
adipose tissue
24
Q
Biomedical Importance
Fat stored in adipose tissue serves as ____ in the subcutaneous tissues and around certain organs
A
thermal insulator
25
# Biomedical Importance
**Nonpolar lipids** act as ____, allowing **rapid propagation** of **depolarization waves** along **myelinated nerves**;
electrical insulator
26
# Biomedical Importance
**Lipoproteins** occur in both ____ and ____, and also serve to **transport lipid in the blood**.
cell membrane & mitochondria
27
# Biomedical Importance
stored in adipose tissue serves as **thermal insulator** in the subcutaneous tissues and around certain organs;
fats
28
# Biomedical Importance
act as **electrical insulator**, allowing rapid propagation of depolarization waves along myelinated nerves;
nonpolar lipids
29
# Biomedical Importance
occur in both **cell membrane** and **mitochondria**, and also serve to **transport lipid in the blood**.
lipoproteins
30
* Important **dietary constituents**
* **High energy value**
* Contains **fat-soluble vitamins** and **essential fatty acids**
lipids
31
* Are **necessary fats** that humans **cannot synthesize**, and must be **obtained through diet**.
* Are **long-chain polyunsaturated fatty acids** derived from linolenic, linoleic, and oleic acids.
essential fatty acids
32
# **Classification** of Based on the “alcohol component”
Ester of fatty acid and **low** MW **monohydric** alcohol
simple lipid
33
# **Classification** of Based on the “alcohol component”
* esters of **three molecules of fatty acids** plus **one molecule of glycerol**.
* Found in adipose tissue, butterfat, lard, suet, fish oils, olive oil, corn oil
triglycerides
34
# **Classification** of Based on the “alcohol component”
ester of fatty acid and **glycerol**
fats/fixed oil
35
# **Classification** of Based on the “alcohol component”
ester of fatty acid and **high** MW **polyhydric** alcohol
waxes
36
# **Classification** of Based on the “alcohol component”
butterfat, lard, suet, fish oils, olive oil, corn oil
triglycerides
37
# **Classification** of Based on the “alcohol component”
beeswax, head oil of sperm whale, cerumen, carnauba oil, and lanolin
waxes
38
the **only** vegetable oil that is **solid** at room temp
cocoa butter
39
____ can be converted into smaller molecules by **hydrolysis**
hydrolyzable lipids
40
* **cannot be cleaved** into smaller molecules by aqueous hydrolysis
* **resistant** to hydrolysis
Nonhydrolyzable lipids
41
**head oil of sperm whale** contains
spermaciti
42
**expensive oil** coming from the **sperm whale**
ambergris
43
**Hydrolyzable** lipids are derived from
fatty acids
44
**Fatty acids** are ____ with **long** C chains of **4-36 (even number)** C atoms.
carboxylic acids (RCOOH)
45
**Naturally occurring fatty acids** have an ____ number of C atoms.
even
46
have **no double bonds** in their long hydrocarbon chains.
saturated fatty acids
47
have **1** or **more double bonds** (generally cis) in their long hydrocarbon chains.
unsaturated fatty acids
48
As the **number of double bonds** in the fatty acid **increases**, the **melting point** ____.
decreases
49
**nomenclature** used in **unsaturated** fatty acids
omega nomenclature
50
can act as **hormones**
prostaglandins
51
melting point of **stearic acid**
71C
52
melting point of **oleic acid**
16C
53
chemical formula of **saturated** fatty acids
CnH2nO2
54
chemical formula of **unsaturated** fatty acids
CnH2n - (2 no. of db) O2
55
**unsaturated** fatty acids with **1 double bond**
monounsaturated
56
**unsaturated** fatty acids with **more than 1 double bond**
polyunsaturated
57
**simplified** nomenclature
chain length : double bonds
58
# **NOMENCLATURE**
**carboxyl** (COOH) carbon will be labeled as
C1
59
# **NOMENCLATURE**
suffix - **unsaturated**
enoic acid
60
# **NOMENCLATURE**
the **terminal** CH3 is called
omega carbon
61
Humans require which fatty acid
| essential fatty acid
omega-3 linolenic acid
62
**Precursor** in the **synthesis** of **eicosapentaenoic acid (EPA)** and **docosahexaenoic acid (DHA)**
omega-3
linolenic acid
63
# PHYSICAL and PHYSIOLOGIC PROPERTIES OF FATTY ACIDS
____ of **even numbered** carbon fatty acids:
* **increases** with **chain length**
* **decreases** according to **unsaturation**
melting point
64
# PHYSICAL and PHYSIOLOGIC PROPERTIES OF FATTY ACIDS
containing **three saturated** fatty acids of 12 C or more is **solid** at body temperature
▫ **18:2 fatty residues** are **liquid** at **body temperature to below 0°C**
triacylglycerol
65
# PHYSICAL and PHYSIOLOGIC PROPERTIES OF FATTY ACIDS
must be **fluid** at **all environmental conditions**
▫ **More unsaturated** than storage lipids
membrane lipids
66
* Derived from **eicosa- (20 carbon)** polyenoic fatty acids
* **Arachidonic acid** is the **major precursors**
eicosanoids
67
* Are part of a family of **biologically active lipids** derived from the** twenty-carbon** essential fatty acids or **eicosanoids**;
* Relates to the products of the c**yclooxygenase pathway**
* **Prostanoic acid** as the **central structural element**
* **Three main groups**
▫ Prostaglandins (PGs)
▫ Prostacyclins (PGIs)
▫ Thromboxanes (TXs)
prostanoids
68
**central structural element** of prostanoids
prostanoic acid
69
* behave like lipids but acts as **local hormones**
* Synthesized from eicosanoic polyunsaturated fatty acids (arachidonic acid) to form **cyclopentane ring**
* PG1, PG2, and PG3– numbers are based on the **double bonds** in the side chain
* The **letter component** identifies the **functional groups** of the cyclopentane ring
prostaglandins
70
prostaglandin with **keto** group in 9th position
PGE
71
prostaglandin with **hydroxyl** group in 9th position
PGF
72
* Cyclopentane ring **interrupted** with an **oxygen atom**;
* Its role is in **clot formation (thrombosis)**
thromboxanes
73
two **major** thromboxanes
A2 & B2
74
* Formed via the **lipooxygenase pathway**
* Has **three** (leukotrienes) to **four** (lipoxins) **conjugated double bonds**
LEUKOTRIENES & LIPOXINS
75
a **proinflammatory agents** and causes **bronchoconstriction**, thus play a part in **asthma**
leukotrienes
76
are **esters** formed from a **fatty acid** and a **high** molecular weight alcohol.
waxes
77
scientific name of **sperm whale**
physeter macrocephalus
78
major component of **spermaceti wax**
cetyl palmitate
79
**synthetic form** of cetyl palmitate
cetyl ester wax
80
Because of their **long nonpolar** C chains, waxes are very ____
hydrophobic
81
beeswax is also known as
yellow wax
82
Like other esters, **waxes** are ____ with water in the **presence of acid or base** to **re-form the carboxylic acid** and **alcohol** they came from.
hydrolyzed
83
* are **three esters** formed from **glycerol** and **three molecules of fatty acids**
* **Main storage** forms of fatty acids.
triacylglycerol
84
have three **identical** fatty acid side chains.
simple triacylglycerols
85
have two or three **different** fatty acids.
mixed triacylglycerol
86
contain only **saturated** fatty acids; they make up most **animal fat** and are **solids** at **room temperature.** (no double bond)
saturated tricylglycerol
87
contain **at least one** unsaturated fatty acid; they make up most **vegetable oils** and are **liquids** at room temperature.
unsaturated triacylglycerol
88
have **1** C=C bond.
monounsaturated triacylglycerol
89
have **many** C=C bonds
polyunsaturated triacylglycerol
90
**Increasing** the **number of double bonds** in the fatty acid chain ____ the **melting point** of the **triacylglycerol**.
decreases
91
have **higher melting points**; they are **solids** at room temperature.
fats
92
**Fats** are derived from fatty acids with ____ double bonds.
few
93
have **lower melting points**; they are **liquids** at room temperature.
oils
94
**Oils** are derived from fatty acids having a ____ of double bonds
larger number
95
are used to **build cell membranes**, **insulate the body**, and **store energy** for later use.
fats
96
It is recommended that **no more than** ____% of a person’s caloric intake should come from lipids.
20 - 35%
97
A **high intake** of ____ is linked to **heart disease**.
saturated triacylglycerol
98
**Saturated** fats stimulate ____ synthesis, which can lead to **cholesterol plaques building up inside arteries**. (*atherosclerosis*)
cholesterol
99
**lower the risk of heart disease** by **decreasing the level of cholesterol** in the blood.
unsaturated triacylglycerol
100
Triglycerols formed from ____ are very helpful in **lowering the risk of heart attack**.
omega-3 fatty acids
101
if the **double bond** of the **unsaturated** triacylglycerol is ____, the beneficial effect is **lost**.
trans
102
* primarily **synthesized** instead of naturally occurring
* act like **saturated** fats and **increase** the **cholesterol levels** in the blood.
trans fats
103
**Triacylglycerols** are **hydrolyzed** with water in the **presence** of ____, ____, or ____ (in the body).
acid, base, or enzymes
104
Humans store ____ as **triacylglycerols** in **adipose cells** below the surface of the skin, in the breast area, and surrounding internal organs.
energy
105
The **number** of **adipose cells** is ____
constant
106
**weight gained** or **lost** causes adipose cells to ____ or ____, but **not decrease** or **increase** in **number**
swell or shrink
107
To **metabolize** triacylglycerols for energy, the esters are hydrolyzed by enzymes called
lipases
108
* Esters of fatty acid, alcohol and **another compound**.
* has **more than 1** component
compound lipid
109
* Fatty acid and alcohol plus a **phosphoric acid residue**
* Frequently have **nitrogen-containing bases** and other substituents (glycerophospholipids, sphingophospholipids)
phospholipids
110
# PHOSPHOLIPIDS
the alcohol is **glycerol**
glycerophospholipids
111
# PHOSPHOLIPIDS
the alcohol is **sphingosine**
sphingophospholipids
112
**fatty acid** and **sphingosine** plus **carbohydrate**.
Glycosphingolipids
113
are lipids that contain a **P** atom
phospholipids
114
Two common types of phospholipids
phosphoacylglycerols
sphingomyelins
115
* **Main lipid constituents** of membrane
* Derivatives of phosphatidic acid
phospholipids
116
**Phosphate** is **esterified** with the ____ of a suitable alcohol
-OH
117
intermediate in the **synthesis** of **triacylglycerols**
Phosphatidic acid
118
* are the **main component** of most **cell membranes.**
* Structurally, they resemble a triacylglycerol, except the **third fatty acid** has been **replaced** with a **phosphodiester bonded to an alcohol**.
Phosphoacylglycerols
119
The **two fatty acid side chains** form____ that lie **parallel** to each other.
2 NONPOLAR TAILS
120
The **phosphodiester end** of the molecule is a
charged or polar head
121
One of the **main types** of **phosphoacylglycerols**
cephalin
122
**cephalin** is chemically known as
phosphatidylethanolamine
123
The **second** of the main types of phosphoacyl-glycerols
lecithin
124
**lecithin** is chemically known as
phosphatidylcholine
125
* Phosphoacylglycerol containing **choline**
* **Most abundant phospholipids of the cell membrane** and represent a large proportion of the body’s store of choline
* present in **egg yolks**
* can be used as **lipid lowering**
phosphatidylcholine
lecithin
126
important in **nervous transmission**, as **acetylcholine**, and as a **store of labile methyl group**
choline
127
* **Effective surface-active agent**
* Major constituent of the surfactant **preventing adherence**, due to surface tension, of the inner surfaces of the lungs.
* **Absence**: **Respiratory distress syndrome**
dipalmitoyl lecithin
128
phosphatidyl in **tissues**
phosphotidylserine
129
**inositol** has stereoisomer called
myoinositol
130
Precursor of **second messenger**
PHOSPHATIDYLINOSITOL
131
**important constituent of the cell membrane phospholipids** and cleaved into **diacylglycerol** and **inositol triphosphate** (internal signals or second messenger)
Phosphatidylinositol 4,5-biphosphate
132
* **bisphosphatidyl glycerol**
* Is an important component of the** inner mitochondrial membrane**, where it constitutes about **20%** of the total lipid
* It serves as an **insulator** and **stabilizes** the **activity of protein complexes** important to the **electron transport chain**
CARDIOLIPIN
133
* Are **intermediates** in the **metabolism of phosphoglycerols**
* Important in the **metabolism** and **interconversions** of phospholipids (lysophosphatidylcholine)
* Found in **oxidized lipoproteins** and can **promote atheroschlerosis**
LYSOPHOSPHOLIPIDS
134
* **do not** contain a **glycerol backbone**, they have a **sphingosine backbone instead**.
* **do not** contain an **ester**; their **single fatty acid** is **bonded** to the **backbone** by an **amide bond**.
Sphingomyelins
135
* **10%** of the phospholipids of the **brain** and **muscle**
* Resemble **phosphatidylethanolamine** (ether linked)
* **Alkyl radical** is an **unsaturated alcohol**
PLASMALOGENS
136
* Found in **large quantities** in **brain** and **nerve tissues**
* Yields fatty acid, phosphoric acid, choline, and a complex amino alcohol, sphingosine
SPHINGOMYELINS
137
the **coating** that **surrounds nerve cells**, is **rich in sphingomyelins**.
myelin sheath
138
* **Sphingosine** plus **amino acid**
* Structure **found** in **glycosphingolipids**
CERAMIDE
139
* **Distributed** in **every tissue** of the body
* Nervous tissues (brain)
* Plasma membrane – cell surface carbohydrates
glycolipids
140
glycolipids is also known as
GLYCOSPHINGOLIPIDS
141
* Major glycolipids in **animal tissues**
* **Ceramide + sugar**
Glycosphingolipids
142
Are **complex glycosphingolipids** derived from **glucosylceramide** that contain in addition one or more molecules of a **sialic acid**
GANGLIOSIDES
143
**Major sphingolipid** of **brain** & other **nervous tissue**, **C24** fatty acids
GALACTOSYLCERAMIDE
144
**principal sialic acid** found in **human tissues**.
NEURAMINIC ACID
145
* contains **ceramide**, **one** molecule of **glucose**, **one** molecule of **galactose** and **one** molecule of **NeuAc** (neuraminic acid)
* The **simplest** gangliosides in tissues
GM3
146
**product** of **simple** and **compound** lipid upon **hydrolysis**.
derived lipid
147
* occur in **plant** and **animal** foods
* also **exhibit in complex forms** with other substances
* obtained from **hydrolysis of fats**
* usually contains an **even number** of carbon atoms and are **straight chain** derivatives
fatty acids
148
Acylglycerols, cholesterol, and cholesteryl ester are **uncharged**, so are termed
neutral lipids
149
are a group of lipids whose carbon skeletons contain several **fused rings**
steroids
150
the **most prominent steroid**, is **synthesized** in the **liver** and **found** in **almost all body tissues**.
cholesterol
151
It is **obtained** in the **diet** from many sources, including **meat**, **cheese**, **butter**, and **eggs**.
cholesterol
152
a molecule that is **synthesized** in **one part of an organism**, which then **elicits a response at a different site**.
hormone
153
Two important classes of **steroid hormones**
sex hormones
adrenal cortical steroids
154
**female** sex hormones
estrogen & progestins
155
**male** sex hormones
androgen
156
estrogens that **control development** of **secondary sex characteristics**, **regulate** the **menstrual cycle**, and are **made in the ovaries**.
estradiol
estrone
157
* called the “**pregnancy hormone**”
* it is responsible for the **preparation** of the **uterus** for **implantation of a fertilized egg**.
progesterone
158
* are **androgens** made in the **testes**.
* They control the development of **secondary sex characteristics** in **males**.
testosterone
androsterone
159
* **Synthetic androgen** analogues that **promote muscle growth**
* They have the **same effect as testosterone**, but are **more stable**, so they are n**ot metabolized as quickly**.
* They have come to be used by **athletes** and **body builders**, but are **not permitted in competitive sports**.
* Prolonged use can cause **physical** and **psychological problems**.
anabolic steroids
160
Three examples of **adrenal cortical steroids**
aldosterone
cortisone
cortisol
161
**regulates blood pressure** and **volume** by **controlling** the **concentration** of **Na+** and **K+** in body fluids.
aldosterone
162
serve as **anti-inflammatory agents**, which also **regulate carbohydrate metabolism**.
cortisone
cortisol
163
Prolonged use of these steroids can have undesired side effects, including **bone loss** and **high blood pressure**.
adrenal cortical steroids
164
# Adrenal Cortical Steroids
a **synthetic** alternative, has **similar
anti-inflammatory properties**
prednisone
165
are organic compounds required in **small quantities** for normal metabolism and **must be obtained from the diet**.
vitamins
166
Vitamins are either ____ solube or ____ soluble
water or fat
167
four **fat-soluble vitamins** that are found in fruits, vegetables, fish, liver, and dairy products.
A D E K
168
**fat soluble vitamins** are stored in
adipose cells
169
* found in liver, fish, and dairy products, and is made from **β-carotene**.
* It is needed for **vision** and for **healthy mucous membranes**.
* **deficiency** causes **night blindness** and **dry eyes** and **skin**.
vitamin A
170
* can be **synthesized** from **cholesterol**.
* It can be obtained in the diet from many foods, especially milk, and **helps regulate Ca and K metabolism**.
* **deficiency** causes **rickets** (bone malformation).
vitamin D
171
* **Precursor** of **vitamin D2**
* Occurs in **plants** and **yeast**
* It is turned into **viosterol** by UV light, and is then converted into **ergocalciferol** (a form of Vitamin D)
* Acquires **antirachitic properties** when irradiated with UV light
* A component of **fungal cell membranes**, serving the same function that cholesterol serves in animal cells
ERGOSTEROL
172
* an **antioxidant**, protecting unsaturated side chains in fatty acids from **unwanted oxidation**.
* Deficiency causes numerous **neurological problems**, although it is rare.
vitamin E
173
regulates the **synthesis** of **clotting proteins (prothrombin)**, and **deficiency** of this leads to **excessive or fatal bleeding**.
vitamin K
174
two types of **eicosanoids**
prostaglandins
leukotrienes
175
are **very potent** compounds, which are **not stored in cells**, but rather** synthesized in response to external stimulus**.
eicosanoids
176
Unlike hormones they are **local mediators**, performing their function **in the environment in which they are synthesized**.
Prostaglandins and Leukotrienes
177
are carboxylic acids that contain a **five-membered ring** and have a **wide range of biological activities**.
prostaglandins
178
* are responsible for **inflammation**
* also **decrease gastric secretions**, **inhibit blood platelet aggregation**, **stimulate uterine contractions**, and **relax smooth muscles**.
prostaglandins
179
# PROSTAGLANDINS
**relieve pain** and **inflammation** by **blocking the synthesis** of these molecules.
Aspirin and ibuprofen
180
two different **cylcooxygenase enzymes** responsible for **prostaglandin synthesis** called
COX-1 & COX-2
181
involved in the **usual production** of prostaglandins.
COX-1
182
responsible for **additional prostaglandins** in **inflammatory diseases** like **arthritis**.
COX-2
183
**inactivate** both COX-1 and -2, but **increase risk** for **stomach ulcer formation**.
NSAIDS
184
Drugs sold as **Vioxx**, **Bextra**, and **Celebrex** block **only** the____ enzyme** without affecting gastric secretions**.
COX-2
185
**Asthma** is characterized by **chronic inflammation**, so ____ to **reduce** this **inflammation** are **commonly used**.
INHALED STEROIDS
186
are molecules that **contribute** to the **asthmatic response** by **constricting** smooth muscle of the lung.
LEUKOTRIENES
187
**New** asthma drugs act by blocking the synthesis of ____, which **treat the disease** instead of just the inflammation symptoms.
LEUKOTRIENE C4
188
**Not** steroids, but **synthesized** like **cholesterol**
POLYPRENOIDS
189
participates in **respiratory chain** in
mitochondrion
UBIQUINONE
190
takes part in **glycoprotein synthesis** by transferring carbohydrate residues to asparagine residues of polypeptide
DOLICHOL
191
rubber, camphor, fat soluble- Vit A, D, E & K and -carotene (provitamin A).
ISOPRENOID
192
* Lipids **exposed to oxygen** (Auto-oxidation).
* A **chain reaction** providing a **continuous supply of free radicals**.
* Effects of iclude:
– **deterioration** of food (rancidity)
– **damage of tissue** (cancer, inflammation, atheroschlerosis and aging) **caused by free radicals** containing **methylene-interrupted double bonds**
LIPID PEROXIDATION
193
Catalyzed in **vivo** by **heme compounds** and by **lipoxygenases** (platelets and leukocytes)
PEROXIDATION
194
# products of auto-oxidation
formed from **cholesterol**
OXYSTEROLS
195
# products of auto-oxidation
prostanoids
Isoprostanes
196
* **Control** and **reduce lipid peroxidation**
* for food are propyl gallate, BHA, BHT
ANTIOXIDANTS
197
# ANTIOXIDANT
**lipid** soluble
VIT E
198
# ANTIOXIDANT
**water** soluble
VIT C
URATE
199
**reduce the rate of chain initiation**.
* Catalases and Peroxidases
* glutathione peroxidase (reacts with ROOH)
* Selenium
* EDTA, DTPA (Chelators of metal ions)
PREVENTIVE ANTIOXIDANTS
200
# ANTIOXIDANTS
trap **superoxide free radicals**
SUPEROXIDE DISMUTASE
201
# ANTIOXIDANTS
lipid phase trap **ROO radicals**
VIT E
202
Contain predominantly **nonpolar groups plus a polar
group**.
* Molecule is **partly** hydrophobic and hydrophilic.
* Include fatty acids, phospholipids, sphingolipids, bile
salts, and cholesterol.
* **Oriented at oil**: water interfaces with the polar group
in water phase and the nonpolar group in the oil
phase.
* **Basic structure of biologic membranes (bilayer).**
AMPHIPHATIC LIPIDS
