QE CC1 Lipids

C

Which of the following is a core physical characteristic of all lipids?

• a. Soluble in water

• b. Insoluble in organic solvents

• c. Insoluble in water

• d. Highly polar molecules

B

Lipids are transported through the bloodstream by binding to specific proteins, forming macromolecular complexes called:

• a. Apolipoproteins

• b. Lipoproteins

• c. Glycoproteins

• d. Phospholipids

D

Which of the following is NOT classified as one of the five main lipids found in human plasma?

• a. Cholesterol

• b. Triglycerides

• c. Non-esterified fatty acids

• d. Nucleic acids

C

Which lipid function involves serving as insulation and a highly concentrated structural element within the nervous system?

• a. Fuel source

• b. Energy storage

• c. Nerve conduction

• d. Aid in digestion

C

Structurally, cholesterol is a large molecule characterized by having how many rings?

• a. Two rings

• b. Three rings

• c. Four rings

• d. Five rings

B

Total cholesterol in the human body originates from hepatic synthesis, cell destruction, intestinal secretions, and what other major source?

• a. Muscle catabolism

• b. Diet

• c. Renal filtration

• d. Adipose breakdown

C

Reused by the liver, cholesterol is highly critical for the formation of which digestive components?

• a. Lipase and amylase

• b. Insulin and glucagon

• c. Bile and bile salts

• d. Cortisol and epinephrine

C

What is the most common routine clinical laboratory method used to measure total cholesterol?

• a. Abell reaction

• b. Ultracentrifugation

• c. Enzymatic end point

• d. Electrophoresis

A

In the chemical extraction reference method for cholesterol (CDC modified Abell reaction), which reaction is used to measure total cholesterol after chemical hydrolysis (saponification)?

• a. Lieberman-Burchard reaction

• b. Sudan Black stain

• c. Glycerol kinase reaction

• d. Oil-Red-O dye

B

According to the National Cholesterol Education Program (NCEP) guidelines, what is the desirable blood cholesterol level for adults over 20 years of age?

• a. < 150 mg/dL

• b. < 200 mg/dL

• c. 200–239 mg/dL

• d. ≥ 240 mg/dL

B

According to the NCEP guidelines, a total cholesterol value of 225 mg/dL is classified as:

• a. Desirable blood cholesterol

• b. Borderline high blood cholesterol

• c. High blood cholesterol

• d. Optimal blood cholesterol

C

A total serum cholesterol level of 250 mg/dL falls into which NCEP clinical category?

• a. Desirable blood cholesterol

• b. Borderline high blood cholesterol

• c. High blood cholesterol

• d. Normal blood cholesterol

C

Chemically, triglycerides are defined as esters consisting of glycerol and how many fatty acids?

• a. One fatty acid

• b. Two fatty acids

• c. Three fatty acids

• d. Four fatty acids

A

Triglycerides serve as the main source of energy and represent the primary ______ form of lipids in humans.

• a. Storage

• b. Transport

• c. Structural

• d. Excretory

B

Which of the following sets of hormones and enzymes are responsible for breaking down triglycerides?

• a. Amylase, insulin, and thyroxine

• b. Lipase, cortisol, and epinephrine

• c. Protease, glucagon, and estrogen

• d. Cholesterol oxidase, aldosterone, and lipase

A

What is the desirable fasting serum triglyceride reference range for adult males?

• a. 40–160 mg/dL

• b. 35–135 mg/dL

• c. < 100 mg/dL

• d. 150–200 mg/dL

B

What is the desirable fasting serum triglyceride reference range for adult females?

• a. 40–160 mg/dL

• b. 35–135 mg/dL

• c. < 50 mg/dL

• d. 200–239 mg/dL

B

In the most common enzymatic methods for measuring triglycerides, what occurs during the first step of the reaction?

• a. Conversion of glycerol to glycerol-1-phosphate by glycerol kinase

• b. Hydrolysis of triglycerides to glycerol and fatty acids by lipase

• c. Consumption of NADH by pyruvate kinase

• d. Formazan color development by glycerol phosphate dehydrogenase

C

Which of the following is NOT classified as a major lipoprotein class?

• a. Chylomicrons

• b. Very low density lipoprotein (VLDL)

• c. Intermediate density lipoprotein (IDL)

• d. High density lipoprotein (HDL)

D

Which of the following is classified as a minor lipoprotein?

• a. Low density lipoprotein (LDL)

• b. Very low density lipoprotein (VLDL)

• c. Chylomicrons

• d. Lipoprotein (a)

D

Which is the largest of all lipoprotein particles?

• a. VLDL

• b. LDL

• c. HDL

• d. Chylomicrons

B

Where do chylomicrons primarily arise and get absorbed into circulation?

• a. Liver

• b. Intestine

• c. Pancreas

• d. Adipose tissue

C

What distinct visual appearance characterizes a fasting plasma specimen containing elevated chylomicrons after it has been refrigerated overnight?

• a. A completely clear and green tint

• b. A uniform dark red precipitate

• c. A "milky" layer on the top of the plasma

• d. A bright yellow crystalline sediment

C

Which major lipoprotein is produced in the liver, possesses a high triglyceride content, and transports endogenous triglycerides to adipose and muscle tissue?

• a. Chylomicrons

• b. Low-density lipoprotein (LDL)

• c. Very low-density lipoprotein (VLDL)

• d. High-density lipoprotein (HDL)

B

Which lipoprotein is exceptionally high in cholesterol content and arises directly from the lipolysis of VLDL?

• a. Chylomicrons

• b. Low-density lipoprotein (LDL)

• c. High-density lipoprotein (HDL)

• d. Lipoprotein (x)

B

An increased clinical fraction of which lipoprotein cholesterol is directly associated with an increased risk for atherosclerosis?

• a. HDL

• b. LDL

• c. Chylomicrons

• d. LP x

D

Which lipoprotein is the smallest and most dense, binds excess cholesterol, and transports it back to the liver?

• a. Chylomicrons

• b. VLDL

• c. LDL

• d. HDL

D

Based on chemical compositions, which major lipoprotein has the highest percentage of triglycerides (80% to 95%)?

• a. VLDL

• b. LDL

• c. HDL

• d. Chylomicrons

D

Which major lipoprotein features the highest percentage of total protein content (45% to 55%)?

• a. Chylomicrons

• b. VLDL

• c. LDL

• d. HDL

B

Which abnormal lipoprotein is characteristically found in the serum of patients suffering from obstructive biliary disease?

• a. Lipoprotein (a)

• b. Lipoprotein x (LP x)

• c. Beta-VLDL

• d. Intermediate density lipoprotein (IDL)

C

Beta-VLD, also called floating beta-lipoprotein, is absent in healthy individuals but accumulates in which metabolic disorder?

• a. Type I hyperlipoproteinemia

• b. Type II(a) hyperlipoproteinemia

• c. Type III hyperlipoproteinemia

• d. Type IV hyperlipoproteinemia

C

Based on physical characteristics during separation, what is the electrophoretic mobility designation of Very Low Density Lipoprotein (VLDL)?

• a. Origin / Cathode

• b. Beta

• c. Pre-beta

• d. Alpha

D

When performing lipoprotein electrophoresis, which fraction remains stationary at the origin (cathode)?

• a. LDL

• b. VLDL

• c. HDL

• d. Chylomicrons

B

What is the electrophoretic mobility classification of Low Density Lipoprotein (LDL)?

• a. Origin

• b. Beta

• c. Pre-beta

• d. Alpha

D

Which major lipoprotein carries the highest relative rate of charge migration and migrates the fastest toward the anode?

• a. Chylomicrons

• b. LDL

• c. VLDL

• d. HDL

C

Which formula is commonly utilized in laboratories to calculate low-density lipoprotein cholesterol (LDLc)?

• a. Abell formula

• b. Frederickson formula

• c. Friedewald formula

• d. Levy formula

A

What is the equation used to estimate VLDL cholesterol (VLDLc) in mg/dL using the Friedewald formula if the triglyceride level is lower than 400 mg/dL?

• a. VLDL = TG / 5

• b. VLDL = TG x 0.16

• c. VLDL = TG / 2.175

• d. VLDL = TG - HDL

D

The Friedewald calculation formula is completely unreliable if fasting triglyceride levels are above _____?

• a. 150 mg/dL

• b. 200 mg/dL

• c. 250 mg/dL

• d. 400 mg/dL

C

Direct (homogeneous) LDL methods are highly useful in clinical settings because they avoid triglyceride interference up to at least what value?

• a. 200 mg/dL

• b. 400 mg/dL

• c. 600 mg/dL

• d. 1000 mg/dL

B

What terminology refers to the specific proteins that comprise the protein portion of a lipoprotein molecule?

• a. Glycoproteins

• b. Apolipoproteins

• c. Lipids

• d. Fatty acids

C

Which apolipoprotein is the major protein component of HDL and is responsible for activating lecithin-cholesterol acyltransferase (LCAT)?

• a. Apo B

• b. Apo C

• c. Apo A

• d. Apo E

B

What is the major protein constituent of LDL, as well as 40% of VLDL and chylomicrons?

• a. Apo A

• b. Apo B

• c. Apo C

• d. Apo D

A

Which specific form of Apolipoprotein B is the most common form and serves as the ligand for LDL receptor binding?

• a. Apo B-100

• b. Apo B-48

• c. Apo B-75

• d. Apo B-20

D

Which apolipoprotein is clinically noted for its significant association with Alzheimer's disease?

• a. Apo A-I

• b. Apo B-48

• c. Apo C-II

• d. Apo E

C

According to apolipoprotein function classifications, which apolipoprotein serves to activate Lipoprotein Lipase (LpL)?

• a. Apo A-I

• b. Apo B-100

• c. Apo C-II

• d. Apo C-III

C

Which classification system is used to categorize hyperlipoproteinemias based on visual inspection of serum patterns and lipoprotein electrophoresis?

• a. National Cholesterol Education Program system

• b. Friedewald-Levy system

• c. Frederickson Levy classification system

• d. Abell-Kendall system

D

Type I hyperlipoproteinemia is characterized by an elevation of which specific lipoprotein class?

• a. LDL

• b. VLDL

• c. IDL

• d. Chylomicrons

B

Type II(a) hyperlipoproteinemia is characterized by an increase in which lipoprotein?

• a. Chylomicrons

• b. LDL

• c. VLDL

• d. IDL

C

What term describes the formation of arterial lesions containing lipid material including cholesterol, which serves as the leading cause of coronary heart disease?

• a. Hyperlipoproteinemia

• b. Saponification

• c. Atherosclerosis

• d. Dysbetalipoproteinemia

A

According to the major risk factors for Coronary Heart Disease (CHD) listed in the guidelines, an HDL cholesterol level below what value is designated as an independent major risk factor?

• a. < 35 mg/dL

• b. < 50 mg/dL

• c. < 60 mg/dL

• d. < 100 mg/dL