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Which of the following is responsible for down regulation of fatty acid synthesis under low energy conditions?

AMP activation of AMP activated protein kinase (AMPK)

Human can convert cholesterol to each of the following except

CO2+H2O

What is the role of Carnitine acyltransferase-I?

Reacts with acyl-CoA and L-carnitine to transfer the acyl chain to make acyl-carnitine

The E2 stage of the pyruvate dehydrogenase cascade involves the cofactors TPP and lipoamide. In the illustrated figure below what reaction is going to occur?

The hydroxyethyl-TPP carbanion will attack then lipoamide disulfide bond leading to a covalent intermediate

What is the role of biotin in the beta-oxidation of ODD chain fatty acids

biotin takes part in the addition of a CO2 from propionyl CoA

The fate of acetate, the product of ethanol metabolism in which of the following?

is taken up by other tissues and activated to acetyl CoA

What happens when fumarate is reduced?

it gains 2H+ and 2e- to make succinate

Tangier disease is characterized by a severe plasma deficiency or absences of HDL by accumulation of cholesterol esters in many tissues throughout the body. Which of the following proteins or enzymes is deficient in this condition?

ABCA1 (ATP binding cassette protein 1)

Which is TRUE of the reciprocal regulation of glycolysis and gluconeogenesis?

ADP inhibits pyruvate carboxylase and activates pyruvate kinase, ATP inhibits phosphofructokinase and ATP activates fructose 1,6-biphosphatase

Triacylglycerol synthesis in adipose tissue occurs only in the fed state. Why?

Adipose tissue lacks glycerol kinase to make glycerol-3-posphate from glycerol. Therefore, glycerol-3-phosphate can only be obtained from the glycolytic pathway (fed state), and the reduction of dihydroxyacetone phosphate (DHAP)

Lovastatin is sued to lower cholesterol by inhibiting the function of which protein?

HMG-CoA reductase

When fatty acid biosynthesis is stimulated, beta oxidation of fatty acids is inhibited. This inhibition occurs mainly because

Malonyl-CoA inhibits carnitine acyltransferase I

A female is admitted to the Emergency department, suffering from nausea and vomiting. Her blood work shows elevated liver enzymes in the blood and highly elevated acetaminophen overdose. In acetaminophen toxicity, which of the following compounds is a toxic intermediate?

N-acetyl-p-benzoquinoeimine (NAPQI)

Odd chain fatty acids and some amino acids produce propionyl CoA. Which of the following is NOT required for the metabolism of propionyl CoA to succinyl CoA

NADH

Suppose 14-C labeled CO2 is used to form malonyl CoA from acetyl CoA. It this labeled malonyl CoA is used for palmitate synthesis, which carbons in the fatty acid would be radiolabeled?

None of the carbons

Bile salts are amphipathic. How does this help emulsify dietary fats?

The epoxide of bile salts face the aqueous environment while the hydrophobic methyl groups interact with insoluble fats

Which of the following statements about chylomicrons in incorrect?

The main role of chylomicrons is to deliver cholesterol to the tissues and fatty acids to the liver

Alcohol abuse is a frequent cause of liver disease in the USA. In recent years, many attempt have been made to help alcoholics stop drinking. Disulfiram is one of the potential pharmacological approaches for preventing alcoholics from drinking. What is the name of the enzyme that is targeted by disulfiram?

acetaldehyde dehydrogenase

Which of the following coenzymes are used by alpha ketoglutarate dehydrogenase complex?

all of the above

How does arsenite poisioning take effect?

arsenite covalently attached to dihydrolipoamide and prevents pyruvate processing to acetyl-CoA

What is the role of biotin in beta oxidation of ODD chain carbon fatty acids

biotin takes part in the addition of a CO2 to propionyl-CoA

Beta-oxidation of fatty acids with even numbers of carbons will produce all of the following expect

butyryl CoA

Beta oxidation of fatty acids with even numbers of carbons will produce all of the following EXCEPT

butyryl-CoA

Which of the following compounds is a potent stimulator of palmitate synthesis, an allosteric activator of acetyl-CoA carboxylase, and a source of both cytoplasmic acetyl-CoA and NADPH for lipogenesis?

citrate

Coenzyme A and acyl carrier protein (ACP) resemble one another since both

contain 4'-phosphopantetheine

In gluconeogenesis the role of pyruvate kinase (in glycolysis) is replaced by what activities?

conversion of pyruvate to oxaloacetate by pyruvate carboxylase and production of phosphoenolypyruvate from oxaloacetate

What is the role of adenylate cyclase in gluconeogenesis?

converts ATP to cAMP, which activates PKA

A patient with a genetic defect in lipoprotein lipase would be expected to exhibit which of the following?

elevated chylomicrons in fasting blood samples

Which of the following is NOT true about fatty acid synthesis?

fatty acids synthesis occurs in the mitochondria

How can excess bile acids be reduced

increase dietary fiber in diet and taking cholestyramine

What is the effect of protein kinase A phosphorylation of fructose 2,6-bisphosphate

inhibits fructose 2,6 bisphosphatase kinase domain

Triacylglycerol synthesis in adipose tissue occurs only in the fed state. It is due to

lack of glycerol kinases in adipose tissue that generates glycerol-3-phosphate is obtained from the glycolytic pathway operated in the fed state with high glucose concentration

Which of the following would be expected to occur after alcohol ingestion

lactic acido

Chronic alcohol results in induction of cytochrome P450 2E1 (CYP2E1) enzyme in the liver. Although the induction is a compensatory mechanism to metabolize excess alcohol, it can have negative consequences BECAUSE it

leads to faster acetaldehyde production that can be cleared

Prior to removal of an acetyl-CoA from and Acyl CoA in beta oxidation, the saturated beta carbon must be

oxidized, hydrated, and oxidized again to form 3-ketoacyl CoA

Glycolysis and gluconeogenesis are reciprocally regulated by a common regulator, fructose-2,6-bisphosphate. Levels of fructose-2,6-bisphosphate are regulated by

phosphorylation of the PFK2/FBPase 2 bifunctional enzyme that increases the level of fructose 2,6 biphosphate

The end product of glycolysis is pyruvate. However, pyruvate cannot directly enter the TCA cycle. What needs to happen to pyruvate for the TCA cycle to proceed?

pyruvate must lose a CO2 when it reacts with TPP and form hydroxyethyl-TPP, the acetyl group linked to TPP must be transferred to lipoamide and CoA-SH acquires an acetyl group to make acetyl-CoA

The carnitine derivatives of fatty acids are utilized for

shuttling fatty acids across the mitochondrial membrane

During vigorous exercise, stimulation of the tricarboxylic acid (TCA) cycle results principally from

stimulation of the flux through a number of TCA cycle enzymes by a decreased NADH/NAD+ ratio

During cholesterol synthesis how is C-30 squalene made?

successive condensation of SIX 5 carbon isoprene molecules

Why do lipoproteins only have a monolayer of phospholipids instead of a typical lipid bilayer?

the acyl chains of the phospholipid monolayer interact with the triglycerides and cholesterol esters of the particle

What is true omega fatty acids?

the omega number is independent of the length of the fatty acid and the omega number indicates where the first double bond is relative to the final carbon in the fatty acid

Fatty acids are adenylated prior to reacting with CoA to make acyl CoA. What is the purpose of the adenylation?

this creates a phosphoester bond that can "attacked" by CoA

A 40 yr old homeless male is brought to the emergency department with confusion, shortness of breath and swelling of his leg. He is known to be an alcoholic and eats poorly, only canned soup and junk food in the homeless shelter. Physical examination indicates compromised left ventricular cardiac contractility. A simple blood test shows no ketoacidosis. What will be the most likely diagnosis?

wet beri-beri caused by nutritional deficiency in vitamin B1