Lesson 15 Module 1

Point out the terminal product of beta-oxidation of Higher Fatty Acids (HFA) with even number of carbon atoms:

A. Butiryl ~ SCoA

B. Malonyl ~ SCoA

C. Acetyl~SCoA*

D. Acetoacetyl ~ SCoA

E. Propionyl~SCoA

Choose the allosteric activator of acetyl-CoA-carboxylase (the key enzyme of HFA synthesis):

A. Malate

B. Oxaloacetate

C. Citrate*

D. Succinate

E. Fumarate

The removal of two-carbon units from a fatty acyl CoA involves four sequential reactions. Which of the following reaction sequences is correct for the pathway of β-oxidation:

1. Oxidation, dehydration, oxidation, cleavage

2. Hydrogenation, dehydration, hydrogenation, cleavage

3. Dehydrogenation, hydration, dehydrogenation, cleavage*

4. Reduction, hydration, dehydrogenation, cleavage

5. Reduction, dehydration, reduction, cleavage

Point out the terminal product in the last round of β-oxidation of High Fatty Acids with odd number of carbon atoms:

A. Butyryl  SCoA

B. Malonyl  SCoA

C. Pyruvate

D. Acetoacetyl  SCoA

E. Propionyl  SCoA*

The formation of the “active form” of a fatty acid is endergonic process in which the ATP energy is consumed. But there is another necessary participant of the fatty acid activation. Choose it:

1. Acetyl CoA

2. CoASH*

3. GTP

4. UTP

5. Succinyl CoA

Point out the cellular location of saturated HFA synthesis:

A. Nucleus

B. Plasmolemma

C. Cytoplasm

D. Mitochondrion

E. Endoplasmic reticulum

Choose the products for one round of stearic acid β-oxidation:

1. 129 ATP

2. 1 Oleyl CoA, 12 ATP

3. 2 acetyl CoA, 2 FADH₂, 1 ATP

4. 1 palmitoyl CoA, 1 acetyl CoA, 1 FADH₂, 1 NADH*

5. 1 stearyl CoA, 1 acetyl CoA, 1 FADH₂, 1 NADH

An experimental animal has been given excessive amount of carbon labeled glucose for a week. In what compound can the label be found?

1. Phenylalanine

2. Methionine

3. Palmitic acid*

4. Vitamin A

5. Arachidonic acid

There is a tissue hypoxia at myocardial ischemia in the patient. Name the process of lipid metabolism, whose rate is reduced in the myocardium at this state:

A. Fat lipolysis

B. Phospholipid synthesis

C. Beta-oxidation of high fatty acids*

D. Cardiolipin synthesis

E. Ketone body synthesis

Which of the following substances is immediate precursor of acetoacetate in pathway ketogenesis?

1. Beta-hydroxybutyrate

2. Acetoacetyl CoA

3. Beta-hydroxybutyryl CoA

4. Acetyl CoA*

5. Beta-hydroxy-beta-methylglutaryl CoA

The most important source of reducing equivalents (NADPH) for fatty acid synthesis in the liver is:

1. Oxidation of acetyl CoA

2. Oxidation of glucuronic acid

3. The pentose phosphate pathway*

4. Glycolysis

5. The citric acid cycle

The energy yield by stearic acid oxidation is:

1. 12

2. 38

3. 96

4. 129

5. 146*

Humans cannot achieve a NET synthesis of glucose from C-even fatty acids due to the inability to convert:

A. Acetyl-CoA to malonyl CoA

B. Acetyl-CoA to acetoacetate

C. Acetyl-CoA to pyruvate*

D. Oxaloacetate to pyruvate

E. Methylmalonyl-CoA to succinyl-CoA

Acetyl CoA carboxylase is key enzyme in fatty acid synthesis. Point out the coenzyme of this enzyme:

1. NADH

2. FADH₂

3. Biotin*

4. Phosphopantetheine

5. CoASH

A microsomal enzyme system is responsible for the formation of some unsaturated fatty acids. Point out an enzyme of the system:

1. NADH-cytochrome b5 reductase*

2. NADH coenzyme Q reductase

3. Succinate coenzyme Q reductase

4. Cytochrome oxidase

5. Coenzyme Q-cytochrome c reductase

Which of the following statements describes correctly ketone bodies?

1. They are accumulated in children with fatty acid oxidation disorders

2. They are accumulated at diabetes mellitus after insulin therapy

3. They are produced by muscle but not by liver

4. They include β-hydroxybutyrate, acetoacetate and acetone*

5. They are most important nutrients for liver

Find out the main substrates for the use by elongase system during the formation of stearyl CoA from palmitoyl CoA:

1. Glycerol, NADPH, palmitoyl CoA

2. Malonyl CoA, NADH, palmitoyl CoA

3. Malonyl CoA, NADPH, palmitoyl CoA*

4. Acetyl CoA, NADPH, palmitoyl CoA

5. Acetyl CoA, NADH, palmitoyl CoA

Point out the biological role of carnitine in cells:

A. Antioxidant

B. Allosteric activator of enzymes

C. Transporter of fatty acid across the mitochondrial membranes*

D. The component of respiratory chain

E. The enzyme inhibitor

Point out the substrate for acyl-CoA-dehydrogenase (beta-oxidation of HFA):

A. Acetyl~SCoA

B. Enoyl~SCoA

C. Butyryl~SCoA*

D. Beta-hydroxyacyl~SCoA

E. Beta-ketoacyl~SCoA

Point out the process or reaction where acetone is formed as end- product:

A. Beta-oxidation of HFA

B. Decarboxylation of acetoacetic acid*

C. Condensation of two acetyl-CoA molecules

D. Synthesis of HFA

E. Decarboxylation of beta-hydroxybutyric acid

A 1 y.o. child with symptoms of muscle affection was admitted to the hospital. Examination revealed carnitine deficiency in muscles. Biochemical base of this pathology is disturbed process of:

1. Regulation of Ca2+ level in mitochondria

2. Transporting of fatty acids to the matrix of mitochondria*

3. Actin and myosin synthesis

4. Lactic acid utilization

5. Substrate phosphorylation

A sportsman was recommended to take a medication that contains carnitine in order to improve his results. What process is activated by carnitine the most?

1. Synthesis of steroid hormones

2. Fatty acids transport to mitochondria*

3. Tissue respiration

4. Synthesis of ketone bodies

5. Synthesis of proteins

It is established, that β-oxidation of high fatty acids is carried out by multienzyme complex in cells. Choose the enzyme that is not the component of this complex:

A. Acyl-CoA-dehydrogenase

B. 3-Hydroxy-acyl-CoA-dehydrogenase

C. Enoyl – CoA - hydratase

D. Aldolase*

E. Thiolase

It is established, that the high fatty acid radical is lengthened in two carbon atoms by palmitate synthetase complex action each cycle. Point out the donor of these two carbon atoms during the synthesis:

A. Stearyl-CoA

B. Palmityl-CoA

C. Lauryl-CoA

D. Malonyl-CoA*

E. Acetyl-CoA

Point out the ketone body that is not utilized in human organism:

A. Acetoacetate

B. Beta-hydroxybutyrate

C. Acetone*

D. All the substances proposed

E. None of the substances proposed

Which of the following steps is involved in the formation of glucose from lipolysis product?

1. 2 glycerols from lipolysis are taken up by liver cells and dimerized to fructose

2. Glycerol from lipolysis is converted to triacylglycerols

3. 2 glycerols from lipolysis are phosphorylated, converted in a few steps to fructose-1,6-bisphosphate, and eventually converted to glucose*

4. Fatty acids from lipolysis are oxidized, producing FADH₂ and stimulating gluconeogenesis

5. Fatty acids from lipolysis are converted to glucose

In uncontrolled diabetes mellitus, acetoacetic acid and beta-hydroxybutyric acid are produced in:

1. Pancreas

2. Liver*

3. Small intestine

4. Kidneys

5. Brain

What compound production and utilization become more significant during starvation?

1. Triacylglycerols

2. Ketone bodies*

3. Glycogen

4. Fatty acids

5. Uric acid

Which of the following organs (tissues) cannot use ketone bodies:

1. Brain

2. Liver*

3. Kidney

4. Myocardium

5. Skeletal muscle