MMSC 407 lipids

Which of the following lipids plays a major role in the formation of myelin sheaths in neurons?

A. Cholesterol

B. Triglycerides

C. Sphingolipids

D. Phosphatidylcholine

Sphinogolipids

In clinical diagnostics, elevated levels of which lipid are most strongly associated with atherosclerosis?

A. HDL cholesterol

B. Phospholipids

C. LDL cholesterol

D. Triglycerides

LDL cholesterol

Lipids are essential in the body for all of the following EXCEPT:

A. Cell membrane structure

B. Hormone synthesis

C. Long-term energy storage

D. Enzyme catalysis

Enzyme catalysis

Which of the following is classified as a simple lipid?

A. Triglyceride

B. Phospholipid

C. Cholesterol

D. Sphingolipid

Triglyceride

Compound lipids are characterized by the presence of:

A. Only carbon and hydrogen

B. Additional groups such as phosphate or carbohydrate

C. Single fatty acid chains only

D. Sterol rings

additional groups such as phosphate or carbohydrate

Which of the following best describes derived lipids?

A. Lipids that are hydrolyzed into fatty acids and alcohol

B. Lipids that contain nitrogen groups

C. Lipids obtained by hydrolysis of simple and compound lipids

D. Lipids that contain multiple double bonds

Lipids obtained by hydrolysis of simple and compound lipids

A lipid consisting of glycerol and three fatty acids is best classified as a:

A. Compound lipid

B. Derived lipid

C. Simple lipid

D. Steroid

simple lipid

Which of the following best describes saturated fatty acids?

A. Contain one or more double bonds

B. Have only single bonds between carbon atoms

C. Are liquid at room temperature

D. Are always essential in the human diet

have single bonds between carbon atoms

Linoleic acid is an example of a:

A. Saturated fatty acid

B. Polyunsaturated fatty acid

C. Monounsaturated fatty acid

D. Trans fatty acid

polyunsaturated fatty acid

Which type of fatty acid has more than one double bond in its carbon chain?

A. Saturated fatty acid

B. Monounsaturated fatty acid

C. Polyunsaturated fatty acid

D. Trans fatty acid

polyunsaturated fatty acid

Trans fatty acids are formed primarily through:

A. Fermentation

B. Hydrogenation of unsaturated fats

C. Oxidation of cholesterol

D. Natural metabolic processes in the liver

hydrogenation of unsaturated fats

Fatty acids can be classified by all the following criteria EXCEPT:

A. Number of carbon atoms

B. Presence and type of double bonds

C. Type of ester linkage

D. Chain length

type of ester linkage

Which of the following is a characteristic of omega-3 fatty acids?

A. The first double bond is at the 6th carbon from the carboxyl end

B. They are synthesized in large amounts in the body

C. The first double bond is at the 3rd carbon from the methyl end

D. They are fully saturated fatty acids

the first double bond is at the 3rd carbon from the methyl end

Short-chain fatty acids typically have:

A. 4-6 carbon atoms

B. 10-14 carbon atoms

C. More than 20 carbon atoms

D. No carboxyl group

4-6 carbon atoms

According to the Dietary Guidelines for Americans, 2020-2025, saturated fat intake should be limited to what percentage of total daily calories?

A. Less than 5%

B. Less than 10%

C. Less than 15%

D. Less than 20%

less than 10%

Which of the following is a primary clinical benefit associated with omega-3 fatty acid consumption?

A. Increased LDL cholesterol

B. Reduced inflammation and lower risk of cardiovascular disease

C. Enhanced glucose absorption in the intestine

D. Increased platelet aggregation

reduced inflammation and lower risk of cardiovascular disease

Which of the following is a rich dietary source of omega-3 fatty acids?

A. Red meat

B. Olive oil

C. Fatty fish (e.g., salmon, mackerel)

D. Whole milk

fatty fish

Which omega-3 fatty acid is most involved in neural and retinal development?

A. Linoleic acid

B. Arachidonic acid

C. Docosahexaenoic acid (DHA)

D. Eicosapentaenoic acid (EPA)

docosahexaenoic acid (DHA)

Which omega-6 fatty acid is a precursor to pro-inflammatory eicosanoids?

A. Alpha-linolenic acid

B. Linoleic acid

C. Arachidonic acid

D. DHA

Arachidonic acid

Which specimen type is typically preferred for free fatty acid analysis?

A. Whole blood

B. Serum or plasma collected after fasting

C. Urine

D. Cerebrospinal fluid

serum or plasma collected after fasting

Which of the following is a gold standard method used for the quantitative determination of free fatty acids in plasma?

A. Enzyme-linked immunosorbent assay (ELISA)

B. Gas Chromatography-Mass Spectrometry (GC-MS)

C. Western blotting

D. Coagulation assay

Gas Chromatography-Mass Spectrometry (GC-MS)

Cholesterol is classified as what type of molecule?

A. Protein

B. Carbohydrate

C. Steroid (Sterol)

D. Phospholipid

steriod(sterol)

The characteristic structural feature of cholesterol includes:

A. A straight-chain hydrocarbon

B. Four fused hydrocarbon rings

C. A glycerol backbone

D. A long-chain polysaccharide

Four fused hydrocarbon rings

Which organ is primarily responsible for endogenous cholesterol synthesis?

A. Kidney

B. Small intestine

C. Liver

D. Pancreas

liver

Cholesterol serves as a precursor for all of the following EXCEPT:

A. Bile acids

B. Steroid hormones

C. Vitamin D

D. Amino acids

Amino acids

In the cell membrane, cholesterol functions to:

A. Synthesize ATP

B. Increase membrane permeability

C. Maintain membrane fluidity and stability

D. Promote protein degradation

maintain membrane fluidity and stability

Which enzyme catalyzes the rate-limiting step in cholesterol biosynthesis?

A. Cholesterol oxidase

B. HMG-CoA reductase

C. Lipoprotein lipase

D. Acetyl-CoA carboxylase

HMG-CoA reductase

Elevated blood cholesterol is most closely associated with which health condition?

A. Diabetes insipidus

B. Hypertension

C. Atherosclerosis

D. Anemia

Atherosclerosis

Which lipoprotein is primarily responsible for transporting cholesterol from the liver to peripheral tissues?

A. HDL

B. VLDL

C. LDL

D. Chylomicron

LDL

The majority of cholesterol in the bloodstream is carried as:

A. Free cholesterol in plasma

B. HDL-bound cholesterol

C. LDL-bound cholesterol

D. Unesterified cholesterol

LDL bound cholesterol

In the intestine, dietary cholesterol is absorbed with the help of:

A. Digestive enzymes only

B. Water-soluble vitamins

C. Bile salts and micelles

D. Chylomicrons directly

bile salts and micelles

Statin drugs primarily lower cholesterol levels by inhibiting which enzyme?

A. Lipoprotein lipase

B. Acetyl-CoA carboxylase

C. HMG-CoA reductase

D. Cholesterol esterase

HMG-CoA reductase

Choleslithiasis refers to the formation of:

A. Kidney stones

B. Pancreatic cysts

C. Cholesterol gallstones in the gallbladder

D. Fatty liver deposits

cholesterol gallstones in the gallbladder

Which of the following is essential to prevent cholesterol precipitation in bile?

A. High blood glucose levels

B. Simultaneous secretion of phospholipids and bile salts

C. Increased absorption of dietary fats

D. Elevated triglyceride synthesis

Simultaneous secretion of phospholipids and bile salts

A deficiency in bile salts may result in which of the following?

A. Hypoglycemia

B. Reduced urea excretion

C. Cholesterol crystallization and gallstone formation

D. Elevated bilirubin conjugation

Cholesterol crystallization and gallstone formation

The phospholipid most commonly involved in solubilizing cholesterol in bile is:

A. Sphingomyelin

B. Phosphatidylinositol

C. Lecithin (phosphatidylcholine)

D. Cardiolipin

Lecithin (phosphatidylcholine)

What condition most likely contributes to the development of cholesterol gallstones?

A. Increased bile salt concentration

B. Decreased cholesterol secretion into bile

C. Decreased bile salt and lecithin secretion relative to cholesterol

D. Enhanced intestinal motility

Decreased bile salt and lecithin secretion relative to cholesterol

Which of the following lipoproteins has the lowest density and the highest lipid content?

A. HDL

B. LDL

C. VLDL

D. Chylomicrons

Chylomicrons

What primarily determines the density of a lipoprotein?

A. Enzyme content

B. Protein to lipid ratio

C. Size of the particle

D. Cholesterol only

protein to lipid ratio

Which lipoprotein is known as "good cholesterol" due to its role in reverse cholesterol transport?

A. VLDL

B. LDL

C. HDL

D. Chylomicrons

HDL

Which lipoprotein is most associated with atherogenic risk when elevated in blood?

A. HDL

B. Chylomicrons

C. VLDL

D. LDL

LDL

The primary function of chylomicrons is to:

A. Transport cholesterol to peripheral tissues

B. Remove excess cholesterol from cells

C. Transport dietary triglycerides from the intestine

D. Deliver fatty acids to the liver

Transport dietary triglycerides from the intestine

Which lipoprotein is produced in the liver and is rich in endogenous triglycerides?

A. HDL

B. Chylomicrons

C. LDL

D. VLDL

VLDL

As VLDL is metabolized in circulation, it is converted to:

A. HDL

B. Chylomicrons

C. LDL

D. Apolipoproteins

LDL

Which of the following lipoproteins contains the highest percentage of protein?

A. HDL

B. LDL

C. VLDL

D. Chylomicrons

HDL

Which lipoprotein is primarily responsible for delivering cholesterol to peripheral tissues?

A. VLDL

B. LDL

C. HDL

D. IDL

LDL

What is the correct order of lipoproteins from lowest to highest density?

A. Chylomicrons → VLDL → LDL → HDL

B. HDL → LDL → VLDL → Chylomicrons

C. LDL → HDL → Chylomicrons → VLDL

D. VLDL → HDL → LDL → Chylomicrons

Chylomicrons --> VLDL --> LDL --> HDL

What is the primary function of high-density lipoprotein (HDL) in lipid metabolism?

A. Transport dietary triglycerides

B. Deliver cholesterol to peripheral tissues

C. Remove excess cholesterol from tissues and return it to the liver

D. Synthesize fatty acids in the liver

Remove excess cholesterol from tissues and return it to the liver

Where are HDL particles primarily synthesized?

A. Pancreas and spleen

B. Adipose tissue and bone marrow

C. Liver and intestine

D. Muscle and kidney

Liver and intestine

Which enzyme is involved in the esterification of cholesterol within HDL particles during reverse cholesterol transport?

A. Lipoprotein lipase (LPL)

B. Lecithin-cholesterol acyltransferase (LCAT)

C. HMG-CoA reductase

D. Acetyl-CoA carboxylase

Lecithin-cholesterol acyltransferase (LCAT)

The cholesterol collected by HDL from peripheral tissues is primarily delivered to the liver for:

A. Triglyceride synthesis

B. Excretion as bile acids or free cholesterol

C. Storage in adipose tissue

D. Conversion into glucose

Excretion as bile acids or free cholesterol

Hypercholesterolemia is primarily characterized by elevated levels of which lipid component in the blood?

A. Triglycerides

B. High-density lipoprotein (HDL)

C. Low-density lipoprotein (LDL)

D. Free fatty acids

Low-density lipoprotein (LDL)

Hypertriglyceridemia is defined by elevated levels of:

A. Cholesterol esters

B. Triglycerides

C. HDL cholesterol

D. Phospholipids

triglycerides

Mixed hyperlipidemia is a condition characterized by elevation of:

A. Only HDL and VLDL

B. Only total cholesterol

C. Both cholesterol and triglycerides

D. Free fatty acids and bile salts

both cholesterol and triglycerides

Which of the following conditions is most commonly associated with secondary hypertriglyceridemia?

A. Iron-deficiency anemia

B. Chronic pancreatitis

C. Diabetes mellitus

D. Osteoporosis

diabeteres mellitus

Which laboratory method is most commonly used for routine screening of hyperlipidemia?

A. Thin-layer chromatography

B. Enzymatic colorimetric assays

C. Western blot

D. Immunofluorescence

enzymatic colorimetric assays

Atherosclerosis is characterized by:

A. Calcium buildup in bones

B. Fibrous tissue formation in the lungs

C. Plaque formation within arterial walls

D. Excessive blood clotting in veins

p;aque formation within arterial walls

Peripheral artery disease (PAD) is most commonly caused by:

A. Muscle fatigue

B. Atherosclerosis narrowing peripheral arteries

C. Vitamin B12 deficiency

D. Kidney infection

atherosclerosis narrowing peripheral arteries

Which lipoprotein is considered most atherogenic?

A. HDL

B. VLDL

C. LDL

D. IDL

LDL

Atherosclerotic plaques may lead to which of the following complications?

A. Hemophilia

B. Aneurysm and thrombosis

C. Increased bone density

D. Hypoglycemia

aneurysm and thrombosis

. A common symptom of peripheral artery disease (PAD) in the legs is:

A. Chest pain

B. Intermittent claudication (pain with walking)

C. Skin rash

D. Headache

Intermittent claudication (pain with walking)

Which of the following lab values is most indicative of atherosclerosis risk?

A. High HDL

B. Low total cholesterol

C. High LDL to HDL ratio

D. High bilirubin

High LDL to HDL ratio

Which intervention is most effective in reducing atherosclerotic risk in patients with hypercholesterolemia?

A. High-protein diet

B. Statin therapy

C. Antibiotics

D. Iron supplements

statin therapy

A lipid panel is primarily used to assess a patient's risk for:

A. Liver disease

B. Cardiovascular disease

C. Anemia

D. Kidney stones

Cardiobascular disease

Which of the following is not typically included in a basic lipid panel?

A. Triglycerides

B. HDL cholesterol

C. Apolipoprotein B

D. LDL cholesterol

Apolipoprotein B

How should a patient typically prepare before a lipid panel blood test?

A. Take a diuretic

B. Eat a high-fat meal

C. Fast for 9-12 hours

D. Exercise vigorously

fast for 9-12 hrs

Elevated levels of which lipid are most associated with pancreatitis?

A. HDL cholesterol

B. Total cholesterol

C. Triglycerides

D. LDL cholesterol

triglycerides

The Friedewald equation is commonly used to calculate:

A. HDL levels

B. Total cholesterol

C. VLDL levels

D. LDL cholesterol

LDL cholesterol

What is the recommended reference range for total cholesterol in adults?

A. <100 mg/dL

B. <200 mg/dL

C. <300 mg/dL

D. <400 mg/dL

<200 mg/dL

A lipid panel result showing high LDL and low HDL levels would indicate:

A. Low cardiovascular risk

B. Normal lipid metabolism

C. Increased risk of atherosclerosis

D. Dehydration

increased risk of atherosclerosis

Non-HDL cholesterol is calculated using which formula?

A. Total cholesterol - Triglycerides

B. LDL cholesterol + HDL cholesterol

C. Total cholesterol - HDL cholesterol

D. LDL cholesterol - HDL cholesterol

total cholesterol - HDL cholesterol

Why is Non-HDL cholesterol considered a better predictor of cardiovascular risk than LDL alone?

A. It includes only triglycerides

B. It accounts for all atherogenic lipoproteins

C. It excludes VLDL

D. It measures HDL levels directly

It accounts for all atherogenic lipoproteins

The CHOD-PAP method for cholesterol measurement is based on:

A. Electrophoresis of lipoproteins

B. Immunoassay detection

C. Enzymatic colorimetric reactions

D. Gas chromatography

Enzymatic colorimetric reactions

Which reagent reacts with hydrogen peroxide in the CHOD-PAP method to produce a color change?

A. Hemoglobin

B. 4-aminophenazone and phenol

C. Ferric chloride

D. Sulfanilic acid

4-aminophenazone and phenol

What does the GPO-PAP method primarily measure to estimate triglyceride concentration?

A. Cholesterol esters

B. Free fatty acids

C. Glycerol

D. Phospholipids

glycerol

At what wavelength range is the absorbance of the quinoneimine dye typically measured in the GPO-PAP method?

A. 300-350 nm

B. 400-450 nm

C. 500-550 nm

D. 600-650 nm

500-550nm