Physio march

Which of the following is the correct formula for calculation of the number of cycles which a fatty acid..... number of carbon atoms in the chain?

(n/2)-1

In bile acid synthesis, the following compounds are involved

7-a-hydroxylase, Taurine, Glycine

In bile acid synthesis the following components are involved

7-alpha-hydroxylase, taurine, glycine

The absorption in GI tract of which compound is NOT going to be impaired under conditions of bile acids deficiency: a) vitamin C b) Vitamin A c) cholesterol d) monoglycerol

?

Choose the false statement a) malonyl-CoA is used in other metabolic pathways in addition to fatty acid biosynthesis (used in FA biosynthesis and Polyketide biosynthesis) b) the formation of malonyl-CoA is the rate-limiting stage c) malonyl-CoA is formed from acetyl-CoA d) malonyl-CoA is an intermediate donor to C2 fragments in the de novo fatty acid synthesis

A

Deficiency of which phospholipid leads to respiratory distress a) Dipalmitoyl-phosphatidylcholine b) phosphatidylinositol c) phosphatidylserine d) phosphatidylethanolamine

A

Dipalmitoylphosphatidylcholine deficiency could lead to a) respiratory distress syndrome b) hyper cholesterol anemia c) dyslipidema d) ketoacidosis

A

Glycerol-3-phosphate, needed for the synthesis of TAGs is produced from dihydroxyacetone phosphate (DHAP) by the enzyme a) glycerol-3-phosphate dehydrogenase with cofactor NADH+H+ b) triode phosphate isomerase c) glycerol-3-phosphate dehydrogenase with cofactor NAD+ d) glycerol-3-phosphate dehydrogenase with cofactor NADPH+H+

A

In intestinal mucosal cells the initial substrate for TAG synthesis is a) 2-monoacylglycerol b) DHAF c) Glycerol-3-phosphate d) glucose

A

In which of the cases will the plasma cholesterol concentration rise a) decreased LDL receptors b) dietary intake of bile acids and enzymes c) inhibition of the enzyme HMG-CoA reductase d) increased production of bile acids

A

NADPH, that is necessary for the synthesis of fatty acids, is produced by the a) pentose phosphate pathway b) carnitine shuttle c) substrate phosphorylation d) ocidative phosphorylation

A

Order the following lipoproteins by increasing density a) CM-VLDL-LDL-HDL b) CM-HDL-VLDL-LDL c) HDL-LDL-VLDL-CM d) LDL-HDL-CM-VLDL

A

Palmitate regulates its own biosynthesis by inhibiting the enzyme a) Acetyl CoA carboxylase b) isocitrate dehydrogenase (cytosolic) c) glucose 6 phosphate dehydrogenase

A

Secretion of secretin is stimulated by a) low pH of chymus b) high pH of chymus c) carbohydrates from the food d) lipids from the food

A

TAGs in the lipoprotein particles are degraded by the enzyme a) capillary lipoprotein lipase b) cholesterol esterase c) pancreatic lipase d) Phospholipase C

A

The enzyme phospholipase A2 could be inhibited by a) steroidal anti-inflammatory drugs b) aspirin c) barbiturates d) antihistamines

A

The synthesis of TAGs proceeds rapidly a) after carbohydrate-rich meals b) during fasting c) at high physical activity d) at high glucagon levels in the blood

A

Which lipase enzyme catalyzes the hydrolysis of TAG in the duodenum a) Pancreatic lipase b) phospholipase c) hormone-sensitive lipase d) capillary lipoprotein lipase

A

Which of the following enzymes catalysed the activation of fatty acids into fatty acyl-CoA a) acyl-CoA synthetase b) acyl-CoA dehydrogenase c) acyltransferase d) Acryl-CoA transacylase

A

Which of the following is NOT an inhibitor for cholesterol biosynthesis a) Insulin b) Glucagon c) Cholesterol d) Lovastatin

A

Which of the following statement is correct about LDL lipoprotein complexes a) they deliver cholesterol to peripheral tissues b) they are rich of TAGs c) they are produced in the liver and the intestines d) they are antiatherogenic

A

Which of the statements concerning the action of the enzyme phospholipase A2 is true a) hydrolysis of the ester bond on carbon 2 and obtaining of the products phosphorylcholine and arachnidoic acid b) hydrolysis of the ester bond on carbon 3 and obtaining of the products 1,2-DAG and phosphocholine c) hydrolysis of the ester bond between phosphatidate and Chopin obtaining of the products phosphatidate and choline d) hydrolysis of the ester bond on carbon 2 and obtaining of the products lysophosphatidylcholine and fatty acid

A

Secretion of cholecystokinin hormone is stimulated by a) HCL from stomach b) low pH from the chymus c) carbohydrates from the food d) lipids from the food

A (by google), D (from Lippincott)

Acetyl-CoA carboxylase contains as a prosthetic group a) thiamine pyrophosphate b) biotin c) methylcobalamin d) pyridoxal phosphate

B

Capillary lipoprotein lipase (LPL) is activated by a) Apo E b) Apo C2 c) it is always active d) Apo A

B

In which of the following combinations both compounds are ketone bodies synthesized during fasting from acetyl-CoA a) acetone and lactate b) 3-hydroxybutyrate and acetoacetate c) acetoacetate and succinate d) pyruvate and 3-hydroxybutyrate

B

Mark the INCORRECT statement about carnitine a) it is endogenously synthesized in liver and kidneys b) the only source of carnitine for the body is food c) the meat is rich in carnitine d) it's deficiency could cause muscle weakness

B

Monoacylglycerol pathway for synthesis of triacylglycerol from 2-monoacylglycerols (2-MAG) and fatty acids exists in the cells of: a) nerve tissue b) intestinal mucosa c) adipose tissue d) liver

B

One of the metabolic effects of cholesterol, received by receptor-mediated endocytosis in the peripheral cells is a) to activate the synthesis of new LDL receptors b) to activate the enzyme Acyl-CoA cholesterol Acryl transferase (ACAT) c) to activate the enzyme HMG-CoA reductase d) none of these statements

B

Point the intracellular localisation of the enzyme Acyl-CoA synthetase a) attached to the ER membrane b) attached to the outer mitochondrial membrane c) localized in the mitochondrial membrane d) attached to the inner mitochondrial membrane

B

The activation energy in the synthesis of glycerophospholipids is provided by a) ATP b) CTP c) CDP d) GTP

B

The biosynthesis of TAG is activated by a) fasting b) high levels of insulin c) high levels of glucagon d) fat-rich meal

B

The biosynthesis of fatty acids is carried out in the: a) mitochondria b)cytosol c)? d) Golgi system

B

The enzyme cyclooxygenase 1 (COX1) could be inhibited by: a) antihistamines b) nonsteroidal anti-inflammatory drugs (NSAIDs) c) barbiturates d)corticosteroids

B

The enzyme phospholipase A2 hydrolyzes the phosphorites term bond at carbon 2 in the molecule of lecithin. Which products could be obtained a) diacylglycerol and choline b) one fatty acid and lysolecithin c) two fatty acid and diacylglycerol d) two fatty acid and choline

B

The uncontrolled endocytosis of the oxidized LDL lipoproteins turns the macrophages into foam cells in arterial walls. This process can be inhibited by increased exit of a) vitamin B6 b) Vitamin E c) Vitamin D d) Vitamin K

B

What is TRUE for the enzyme capillary lipoprotein lipase (LPL) a) intracellular enzyme localized on the capillary wall b) it is a membrane bound enzyme with its active site oriented to the lumen of the capillary c) plasma enzyme, which acts only in the capillaries d)degrades lipoprotein complexes

B

What is the fate of glycerol produced during lipolysis in the adipose tissue a) it is included in the glycolysis in muscle tissue b) it is phosphorylated to glycerol-3-phosphate in adipose tissue c) it is transported in the blood associated with albumin d) it is used as a substrate for glyconeigenesis in the liver

B

When the cholesterol is delivered to the cells, it has the following effect a) new production of LDL receptors b) activation of the enzyme ACAT c) activation of the enzyme HMG-CoA reductase d) none of the stated

B

Which are the main apoproteins found in VLDL? a) ApoD and ApoA2 b) Apo B100, ApoE, ApoC2 c) Apo B48, Apo E, ApoC2 d)ApoC2, Apo E

B

Which enzyme is NOT directly reduced to the arachidonic acid a) phospholipase A2 b) cholesterol esterase c) lipoxygenase d) cyclooxygenase

B

Which is the TRUE statement: a) nascent chylomicrons contain mainly cholesterol and cholesterol esters b) deficiency of capillary lipoprotein lipase leads to increased levels of serum triglycerides (TAG) c) APO C-2 is a ligand, recognized by the receptors on the surface of hepatocytes d) mature chylomicrons are derived from enterocytes

B

Which of the compounds are NOT re-esterified to give their derivative after they are absorbed in the enterocytes a) polyunsaturated fatty acid b) short- and medium-chain fatty acid c) long-chain fatty acid d) essential fatty acid

B

Which of the following enzymes catalysed the reversible reaction and is involved in both process, ketogenesis and ketolysis a) 3-hydroxy-3-methylglutaryl CoA lyase b) 3-hydroxybutyrate dehydrogenase c) succinyl CoA acetoacetate CoA transferase/thiophorase d) 3-hydroxy-3-methylglutaryl CoA synthase

B

Which of the following enzymes is responsible for acetoacetate activation during ketolysis? a) succinyl CoA acetoacetate CoA transferase (thiophorase) b) 3-OH butyrate dehydrogenase c) transketolase d) acyl-CoA acyktransferase

B

Which of the following hormones is NOT synthesized from cholesterol a) vitamin D3 hormone b) cholecystokinin and secretin c) sex hormones d) corticosteroids

B

Which of the following is NOT correct for bile acids a) they participate in the emulsification process in intestines b) they maintain the pH c) they eliminate the excess cholesterol d) they participate in fat soluble vitamin absorption

B

Which of the following is a secondary bile acid a) choline acid b) deoxycholic acid c) chenodeoxycholic acid d) glycochenodeoxycholic acid

B

Which of the following statements about TRUE about HDL a) transport of exogenous lipids from the intestines for the liver b) transport of cholesterol from the peripheral tissues to the liver c) transport of endogenous lipids from the liver to the peripheral tissues d) transport of cholesterol from the intestines to the peripheral tissues

B

Which tissue will produce high levels of ketone bodies during prolonged fasting a) muscles b) liver c) adipose tissue d) brain

B

Which of the following statements about the process lipolysis (right / wrong) a) localized in the cytosol b) takes place in the adipocytes c) the process is active under conditions of ... d) localized in the mitochondria

B is right and D is false

Cholesterol is NOT a substrate for synthesis of a) steroid hormones b) Vitamin D3 c) acetyl-CoA d) bile acid

C

Dipalmitoylphosphatidylcholine is a phospholipid, which is one of the predominant components is a) inflammatory biological response b)arachidonic acids pool c) lung surfactant d) blood-group antigens

C

Familial Hypercholesterolemiais NOT characterized by a) high LDL plasma levels b) high cholesterol levels in plasma c) Low LDL plasma levels due to delayed LDL lipoprotein metabolism and prolonged time in blood d) early development of atherosclerosis

C

Mark the CORRECT statement a) the carboxylation of acetyl-CoA to malonyl CoA is catalyzed by acetyl CoA decarboxylase b) the inner mitochondrial membrane is permeable for acetyl CoA c) the initial substrate for the biosynthesis of fatty acids is acetyl-CoA d) synthase of fatty acids is a heptamer in humans

C

Mark the CORRECT statement a) the rate fatty acid biosynthesis is much lower after a carbohydrates rich meal b) very low, intermediate and low density lipoproteins are a dynamic interaction and... c) apolipoprotein B-100 is synthesized in the small intestine and is one of the longest known polypeptide chains d) adipocytes can't synthesize triacylglycerol at high plasma levels of glucose and insulin

C

Nascent Chylomicrons have a) Apo E b) Apo C2 c) Apo B48 d) Apo B100

C

One of the main mechanisms for cholesterol elimination from the body is a) package and export by lipoproteins b) conversion in bilirubin that is secreted in the intestines c) bile acid synthesis and secretion in the intestines d) hydrolysis to CO2 and H2O

C

Point the WRONG statement about capillary lipoprotein lipase a) it's active side faces the lumen of the capillaries b) it hydrolyzes triacyl glycerols (TAG) included in the composition of chylomicrones to produce fatty acids and glycerols c) it is synthesized and secreted in nerve tissue d) it is bound with heparin sulphate to the epithelial cells of capillary well

C

Point the characteristic which is NOT typical for Chylomicrons: a) lipoprotein complexes with lowest density b) they contain mainly triacyglycerols c) structural apolipoprotein is apo B-100 d)?

C

The enzyme hormone-sensitive lipase a) is active in dephosphorylated state b) gets activated mainly by insulin c) gets activated mainly by epinephrine (adrenaline) d) it's most powerful activator is glucagon

C

What is the cell localisation of the process ketogenenesis a) Golgi apparatus b) ER c) mitochondria d) cytosol

C

What is the cell localisation of the process ketolysis a) Golgi apparatus b) EPR c) Mitochondria d) cytosol

C

Which of the following conditions would not cause ketoacidosis a) diabetes b) ketonemia c) increased plasma volume d) enhanced lipid metabolism and slow carbohydrates metabolism

C

Which of the following enzymes for achidonic acid metabolism is involved in the synthesis of prostaglandins a) phospholipase A2 b) cyclooxygenase c) lipoxygenase d) cytochrome P450 Monooxygenase

C

Which of the following functions does NOT belong to the bile acids? a) their synthesis is related to cholesterol elimination b) they are responsible for emulsification of fat droplets c) they have bactericide activity due to their acidic properties d) they are involved in the formation for micelles for the absorption process of the products of lipid digestion

C

Which of the following metabolites is not part of cholesterol biosynthesis a) squalane b) lanosterole c) progesterone d) mevalonate

C

Which of the following sentences is true a) secondary bile acids have more effective functional activity compared with primary conjugated bile acids b) secondary bile acids are synthesized in the liver c) conjugated bile acids have more effective functional activity compared with non-conjugated d) primary bile acids are synthesized in gallbladder

C

Which of the following statements does NOT ? (Bile acids) a) they are amphipathic molecules b) they activate some pancreatic enzymes which.... c) facilitate the conversion of nascent Chylomicrons d) they emulsify the lipids and participate in formation of...

C

Which of the following statements is INCORRECT for HDL lipoproteins a) they have high density and low size b) they are a storage form of Apo II c) they have Apo B100 d) they take from the peripheral tissues non-esterified cholesterol using the enzyme LCAT

C

Which of the following statements is TRUE for VLDL a) transport of cholesterol from the intestines to the liver b) transport of cholesterol from the peripheral to the liver c) transport of endogenous lipids from the liver to the peripheral tissues d) transport of exogenous lipids from the intestines to...

C

Which of the following statements is incorrect for LCAT a) participates in the mechanism for extraction of non-esterified cholesterol in the peripheral tissue b) it's a plasma enzyme c) the enzyme is produced in the extrahepatic tissue d) the enzyme esterifies cholesterol in the HDL lipoproteins

C

Which one is NOT a function of apoproteins a) they have a structural function b) they bind to receptor on the cell surface c) they have enzymatic activity d) they activate enzymes

C

Which one is NOT correct for bile acids a) they provide transport of exogenous lipids in enterocytes and their absorption b) they participate in emulsification of lipids in duodenum c) absolute deficiency of bile acids lead to improper absorption of Vitamin C d) they activate some pancreatic enzymes

C

A lipid that does NOT have a sphingosine backbone is a) ganglioside GM b) sphingomyelin c) phosphatidylinosil d) ceramide e) cerebroside

C (?)

Carboxylation of acetyl-CoA to malonyl-CoA requires

CO2 and ATP

An infant, born prematurely at 28 weeks of gestation, has clinical signs for respiratory distress syndrome. Which of the following statements about this syndrome is true? a) the marker for the condition is the level of sphingomyelin in the amniotic fluid b) the treatment of the condition includes surfactant administration to the mother just before she gives birth c) it is unrelated to the baby's premature birth d) the concentration of dipalmitoylphosphatidylcholine in the amniotic fluid would be expected to be lower than that of a full-term baby

D

Choose the correct combination of substrate for cholesterol biosynthesis a) Acetyl CoA and NAD+ b) Pyruvate and NAD+ c) Glucose and NADP+ d) Acetyl CoA and NADPH

D

Choose the correct statement a) ATPr is 4-phosphopancetin Derivate of lipoic acid b) free -OH group of ATPr binds malone from malonyl CoA c) ATPr carries only acetyl but not acyl group d) fatty acid synthase contains 7 enzymatic activities and one acyl-transporting protein (ATPr)

D

Choose the correct statement: a) the cytosolic citrate is cleaved by the enzyme citrate ligament b) in the cytosol citrate is cleaved to acetyl CoA and maleate c) the fatty acids synthase is composed of 4 polypeptide chains d) the carbon atoms of malonyl-CoA are used in the elongation step in the de novo synthesis of saturated fatty acids

D

Cofactor of the enzyme acetyl-CoA carboxylase is a) methylcobalamin b) deoxy adrenal cobalamin c) thiamine pyrophosphate d) biotin

D

How many ATP molecules could be yielded after one cycle of beta-oxidation of fatty acids? a) 131 b) 4 c) 129 d) 5

D

How many molecules of malonyl-CoA are required to synthesize one molecule palmitate a) 1 b) 18 c) 16 d) 7

D

Mark the INCORRECT statement about carnitine a) it is endogenously synthesized in liver and kidney b) it's deficiency could cause muscle weakness c) the meat is rich in carnitine d) the only source of carnitine for the body is food

D

Phosphatidic acid is an intermediate in glycophospholipids synthesis. Choose the correct combination which describes the structure of phosphatidic acid a) fatty acid residue at carbon 1 and carbon 2, and one phosphate group and one serine at carbon 3 b) amino alcohol, phosphate group and choline at carbon 1 c) fatty acid residue at carbon 1 and 2 and one phosphate group and one choline at carbon 3 d) fatty acyl residues at carbon 1 and 2 and phosphate group at carbon 3

D

Products obtained by the action of the enzyme phospholipase C and the lectin structure are a) cholesterol and choline b) one fatty acid and lysolecithin c) two fatty acids and diacylglycerol d) diacylglycerol and phosphocholine

D

Products obtained by the action of the enzyme phospholipase C on the lecithin structure are a) two fatty acids and diacylglycerol b) one fatty acid and lysolecithin c) cholesterol and choline d) diacylglycerol and phosphocholine

D

Secretin a) activates pancreatic lipase b) it's secretion is stimulated by cholecystokinin c) increase pH in duodenum, by stimulation of the secretion of H2CO3 d) increase in pH in the duodenum, by stimulation of the secretion of HCO3

D

The effect of secretion action is: a) release of bile acids b) release of pancreatic enzymes c) decrease of pH in the duodenum d) release of HCO3- from pancreas

D

The enzyme hormone-sensitive lipase a) it's active in dephosphorylated statements most powerful activator is glucagon b) gets activated mainly by the insulin c) it's most powerful activator is glucagon d) gets activated mainly by epinephrine (adrenaline)

D

What is the cell localisation of the process beta-oxidation of fatty acid a) cytosol b) Golgi apparatus c) EPR d) mitochondria

D

Which is the correct statement about HDL? a) they transport cholesterol as transforming it to cholesterol esters by the help of ACAT enzyme b) they have an atherogenic effect c) they contain ApoB100 d) they transport cholesterol and cholesterol esters from peripheral tissues to the liver

D

Which of the following lipoprotein complexes has highest atherogenic properties? a) CM b) HDL c) VLDL d) LDL

D

Which of the following lipoprotein particles has the lowest density a) mature Chylomicrons b) remnant Chylomicrons c) HDL d) nascent Chylomicrons

D

Which of the following metabolites.... a) mevalonate (HMG-CoA with enzyme HMG-CoA reductase) b) HMG-CoA ( acetoacetyl-CoA with enzyme HMG-Synthase) c) Acetyl CoA ( Krebs cycle) d) Acetoacetyl CoA ( Acetyl-CoA with enzyme thiolase)

D

Which of the following statements about acetone is FALSE a) has a role in pH regulation of blood b) can be degraded in acetyl-CoA c) it is excreted with urine d) it is metabolized into hydroxymetabolites

D

Which of the following statements about carnitine palmitoyl transferase (CPT-1) is INCORRECT a) it is a rate-limiting enzyme from the carnitine shuttle b) it is inhibited by high levels of malonyl-CoA and insulin c) it is localized in the outer mitochondrial membrane d) it is localized in the inner mitochondrial membrane

D

Which of the following statements about the process lipolysis is FALSE a) localized in the cytosol b) takes place in the adipocytes c) the process is active under condition of starvation d) localized in the mitochondria

D

Which of the following tissues CAN NOT use keton bodies as energy source during prolonged fasting a) adipose tissue b) brain c) muscles d) liver

D

Which of the listed compounds participates in transport of fatty acids for beta-oxidation a) Malonyl CoA b) acetyl CoA c) citrate d) carnitine

D

Mark the incorrect statement. The enzyme HMG-CoA ? Inhibitor ? a) statin drugs b) Glucagon ( activator for HMG-CoA reductase) c) cholesterol (HMG-CoA reductase is the regulatory enzyme) d) Insulin ( inhibitor for HMG-CoA reductase)

D (?)

Point the correct statement of lipids digestion: a) lipid digestion starts in the mouth b) formation of mixed micelles is an important step in lipid digestion c)all lipids are digested in the stomach d) the pancreatic lipase degrades triacylglycerols to fatty acids and glycerol

D (a?)

Which of the combination below is the correct order of reactions in one cycle of Beta-oxidation of the fatty acid

Dehydrogenase => hydratase => dehydrogenase => thiolase

Eicosanoids are a) derived from arachidonic acid b) exert their effect at very low concentrations c) usually act very near their site of synthesis d) include prostaglandins, thromboxanes and leukotrienes e) all of the above

E

What is the fate of the products received by the action of capillary lipoprotein lipase

Free fatty acid, bound with albumin are transported to other tissues, where they can undergo beta-oxidation

Simvastatine is a competitive inhibitor which inhibits the regulatory steps of the cholesterol biosynthesis. The product of the inhibited reaction is

Mevalonate ( product of HMg-CoA reductase)

Which of the following reactions/processes is catalysed by the enzyme carnitine-acylcarnitine translocase

Transportation of acyetylcarnitine from inter membrane space to the mitochondrial matrix

Which of the following reactions is catalysed by the malic enzyme

malate + NADP => pyruvate + CO2 + NADPH + NAD+