Lesson 14 Module 1

The lipids are transported by lipoproteins in the blood. Specify the lipoproteins that are formed in the small intestine wall after high lipids intake:

A. HDL

B. Chylomicrons*

C. LDL

D. VLDL

E. IDL

Point out the lipoprotein class transporting cholesterol from peripheral tissues to the liver:

1. VLDL

2. LDL

3. HDL*

4. Chylomicrones

5. Cholesterol-albumin complex

Certain drugs -caffeine and theophylline- inhibit phosphodiesterase activity catalyzing reaction cAMP→AMP. How will free fatty acid levels are altered in the blood after the drugs injection:

1. Will be increased*

2. Will be decreased

3. Will be not altered

4. Will be increased simultaneously with galactose

5. Will be decreased simultaneously with glucose

The liver requires a mechanism for producing phosphatidylcholine (PC) because it exports significant amounts of PC in the bile and as component of serum lipoproteins. This mechanism includes three methylation steps to produce PC from phosphatidylethanolamine. What is the methyl group donor for methylation:

1. S-adenosylmethionine (SAM)*

2. N-guanosylmethionine (NGM)

3. Cytidine diphosphate-choline (CDP-choline)

4. Uridine diphosphate-methionine (UDP-methionine)

5. Homosycteine

Choose the organs or tissues where lipogenesis proceeds most intensively:

A. Skeletal Muscle

B. Brain, pancreas gland

C. Kidneys, adrenal gland

D. Liver, Mammary gland*

E. Myocardium

Which one of the following properties is not characteristic of LDL?

A. LDL is smaller than both VLDL and chylomicrones

B. LDL contains more cholesteryl esters than triacylglycerols

C. The major protein component of LDL is apoB-48 *

D. LDL are more dense than chylomicrons

E. LDL have specific high affinity receptors in most cells

Which statement is incorrect about phosphatidylcholine (PC)?

A. PC may be synthesized from phosphatidylserine or from diacylglycerol and CDP-choline.

B. PC together with phosphatidylethanolamine and phosphatidylserine are major phospholipid components of cell membranes.

C. PC participates in signal transmission via activated phospholipase C*

D. PC is an important component of the surface shell of plasma lipoproteins.

E. PC can be hydrolyzed by phospholipase A₂ into lysolecithin and a fatty acid.

What substance is not a component of lipoprotein:

1. Cholesterol

2. Triacylglycerol

3. Phospholipid

4. Apoprotein

5. Transferrin*

Choose the separation method for lipoproteins of the blood plasm:

A. Radioimmunal Assay

B. Extraction

C. Electrophoresis*

D. Salting-out

E. Photocolorimetry method

Name the condition in the liver cell causing the triacylglycerol synthesis:

A. The decrease of ATP/ADP ratio

B. The accumulation of high fatty acids *

C. The accumulation of carbon dioxide

D. The ketone bodies accumulation

E. The stimulation of protein degradation

Which statement is a true for the comparison of phospholipids (PL) and triacylglycerols (TAG)?

1. Both molecules contain a phosphate group.

2. TAG may be saturated or unsaturated, but all fatty acids in PL structure are saturated

3. Both TAG and PL are the primary storage form for fats in our bodies.

4. PL contein a cyclic steroid ring, whilst triglycerides maintain a straight-chain form.

5. PL molecules have a distinctly polar 'head' and a distinctly non-polar 'tail,' whilst triglycerides are predominantly non-polar*

Point out the enzyme used for lysophospholipid formation during lipolysis of glycerophospholipid:

A. Diacylglycerol lipase

B. Monoacylglycerol lipase

C. Triacylglycerol lipase

D. Phospholipase A_2*

E. Phospholipase D

Synthesis of phospholipids is disordered under the liver fat infiltration. Indicate which of the following substances can enhance the process of methylation during phospholipids synthesis?

1. Glucose

2. Citrate

3. Methionine*

4. Glycerol

5. Ascorbic acid

Vitamin F is recommended in order to prevent the cholesterol deposition inside the blood vessels at atherosclerosis. What lipid is the component of this vitamin?

A. Linoleic acid*

B. Stearic acid

C. Sphingomyelin

D. Cholesterol

E. Cardiolipid

Hormone-sensitive triacylglycerol lipase is activated in adipocytes under the emotional stress. Choose the substance, whose concentration is increased in adipose tissue in this state:

A. cAMP*

B. cGMP

C. AMP

D. Diacylglycerol

E. Ca²⁺

Blood plasma of patient with hyperlipoproteinemia type I remains milky even after a long fast due to markedly elevated and persistent chylomicrons. What abnormality is possible in these patients?

A. Obstruction of the bile duct

B. Deficient pancreatic lipase

C. Defective synthesis of apoB-48

D. Deficient lecithin cholesterol acyltransferase (LCAT)

E. Deficient lipoprotein lipase*

If choline moiety is replaced by ethanolamine in glycerophospholipid the net product is:

1. Cerebroside

2. Sphingomyelin

3. Cephalin*

4. Plasmalogen

5. Cardiolipin

Which is a lipotropic factor:

1. Glycerol

2. Insulin

3. Choline*

4. Carnitine

5. Alanine

Which of the following is an activator of LCAT (Lecithin Cholesterol Acyltransferase)

1. Apo B 100

2. Apo B 48

3. Apo E

4. Apo AI*

5. Apo CII

Free fatty acids are transported in circulation via:

1. Albumins*

2. Globulins

3. Triacylglycerols

4. Chylomicrons

5. HDL

In man the serum lipoprotein fraction with the highest free cholesterol content is:

1. Prealbumin

2. Beta-lipoprotein*

3. Alpha-lipoprotein

4. Chylomicrons

5. Pre-beta-lipoprotein

All of the following statements about LDL are true except:

1. It delivers cholesterol to cells

2. It contains only one apoprotein*

3. It is a marker for cardiovascular disease

4. It contains apo B-100

5. 25% of its content is utilized in the liver

In electrophoresis which class of lipoproteins will least migrate from start-line:

A. Chylomicrons*

B. VLDL

C. LDL

D. IDL

E. HDL

The largest reserve of energy in body is stored as:

A. Liver glycogen

B. Muscle glycogen

C. Triacylglycerols in adipose tissue*

D. Blood glucose

E. Muscle protein

Hormone sensitive triacylglycerol lipase is not activated by one hormone from following list. Point out it.

A. Insulin*

B. Glucagon

C. Epinephrine

D. Norepinephrine

E. None of above