SERUM TRIGLYCERIDE TEST

Question 1

______ are ubiquitous in the body tissue and have an important role in virtually all aspects of life-serving as

hormones or hormone precursors

aiding in digestion

providing energy storage and metabolic fuels

acting as functional and structural components in cell membranes

forming insulation to allow nerve conduction or to prevent heat loss

Answer 1

Lipids

Question 2

The term lipid applies to a class of compounds that are soluble in _____ and nearly insoluble in____.

Answer 2

organic solvents

water

Question 3

lipids are either compound that yields_____ on hydrolysis or

complex alcohols that combine with fatty acids to form_____.

Answer 3

fatty acid

esters

Question 4

Some lipids are more complex, containing non-lipid groups, such as (4).

The presence of these groups gives them the property (_____) of having an affinity for both water and organic solvents, which is important in the formation of membranes.

Answer 4

sialic, phosphoryl, amino, or sulfate groups

amphipathic

Question 5

CLASSIFICATION OF CLINICALLY IMPORTANT LIPIDS

Answer 5

Sterol derivatives
Fatty acids
Glycerol esters
Sphingosine derivatives
Terpenes

Question 6

Sterol Derivatives

Answer 6

• Cholesterol and cholesteryl esters
• Steroid hormones
• Bile acids
• Vitamin D

Question 7

Fatty Acids

Answer 7

• Short chain (2 - 4 carbon atoms;
• Medium chain (6 - 10 carbon atoms)
• Long chain (12 - 26 carbon atoms)
• Prostaglandins

Question 8

Fatty acids

• Short chain
• Medium chain
• Long chain
• Prostaglandins

Answer 8

2 - 4 carbon atoms

6 - 10 carbon atoms

12 - 26 carbon atoms

Question 9

Glycerol Esters

Answer 9

• Tri-, Di-, and Monoglycerides (acylglycerols)
• Phosphoglycerides

Question 10

Sphingosine Derivatives

Answer 10

• Sphingomyelin
• Glycosphingolipids

Question 11

Terpenes (Isoprene Polymers)

Answer 11

• Vitamin A
• Vitamin E
• Vitamin K

Question 12

GLYCEROL ESTERS also known as

Answer 12

ACYLGLYCEROLS

Question 13

Virtually all the complex lipids are fatty acid derivatives, and in most cases, they are covalently linked to an alcohol.

One of the most common alcohols found in human metabolism is____, a three-carbon molecule containing three______

Answer 13

glycerol

hydroxyl groups

Question 14

The two terminal carbon atoms in the molecule are chemically equivalent and are designated a and a’.

The center a carbon is labeled B.

Answer 14

Glycerol esters

Question 15

The class of acylglycerol (glyceride) is determined by the number of_______ present;

one fatty acid, monoacylglycerols (monoglycerides)

two fatty acids, diacylglycerols (diglycerides)

three fatty acids, triacylglycerols (triglycerides)

Answer 15

fatty acyl groups

Question 16

In human nutrition,______ are the most prevalent glycerol esters encountered and constitute____% of tissue storage fat and are the predominant form of glyceryl ester found in plasma.

Answer 16

triglycerides

95%

Question 17

Triglycerides from _____ tend to have large amounts of C18:2 or_____ residues and are liquid at room temperature.

Answer 17

plants (e.g., com, sunflower seed, and safflower oils)

linoleic

Question 18

Triglycerides from_____, especially ruminants, tend to have C12:0 through C18:0 fatty acid residues (saturated fats) and are solids at room temperature.

Answer 18

animals

Question 19

Some plant triglycerides, such as_______, are highly saturated and may be solid at room temperature.

Answer 19

coconut oil

Question 20

Triglycerides are digested in the

Answer 20

duodenum and proximal ileum

Question 21

Through the action of _____and _____ and in the presence of_____, they are hydrolyzed to glycerol, monoglycerides, and fatty acids.

Answer 21

pancreatic and intestinal lipases

bile acids

Question 22

After absorption, triglycerides are resynthesized in the______ and combined with cholesterol and apo B-48 to form_______.

Answer 22

intestinal epithelial cells

chylomicrons

Question 23

(2) are important indicators of CHD (coronary heart disease) risk, which is a major reason for their measurement in research, as well as in clinical practice.

Answer 23

Lipids and lipoproteins

Question 24

The triglyceride value is also commonly used in the estimation of LDL cholesterol by the_____

Answer 24

Friedewald equation

Question 25

1

Several enzymatic reaction sequences are available for triglyceride measurement, all including_____ to cleave fatty acids from the glycerol backbone.

The freed glycerol participates in any one of several enzymatic sequences.

One of the more common earlier reactions, ending in a product measured in the ultraviolet (UV) region, used glycerol kinase and pyruvate kinase, culminating in the conversion of NADH to NAD+ with an associated decrease in absorbance.

Answer 25

lipases

Question 26

2

This reaction #1 is susceptible to interference and side reactions. The UV endpoint is also less convenient for modern analyzers, so this and other UV reaction sequences have been replaced by a second sequence, involving glycerol kinase and glycerol-phosphate oxidase coupled to the same peroxidase ____ reaction described for cholesterol.

Answer 26

color

Question 27

In most specimens, the endogenous free glycerol contributes a _____ overestimation of triglycerides.

Answer 27

10 - 20 mg/dL

Question 28

About_____% of specimens will have higher glycerol, with levels increased in certain conditions, such as diabetes and liver disease or from glycerol containing medications.

Answer 28

20%

Question 29

Reagents are available that correct for______ and are used by many research laboratories, but such methods are less efficient, and hence uncommon in clinical laboratories

Answer 29

endogenous free glycerol

Question 30

The triglyceride reference method involves (3) an assay that is tedious, poorly characterized, and only applied in the lipid standardization laboratory at the Centers for Disease Control and Prevention (CDC) and a few other standardization laboratories.

Answer 30

alkaline hydrolysis
solvent extraction
a color reaction with chromotropic acid