Lesson 13

How glucocorticoids influence the carbohydrate metabolism?

Stimulate the glycolysis from glucose

Stimulate the gluconeogenesis*

Stimulate the starch hydrolysis in the small intestine

Inhibit the glycogen phosphorolysis

Stimulate the glycogenesis

Which one of the following enzymes is associated with glycogen synthesis?

1. Branching enzyme*

2. Glycogen phosphorylase

3. Phosphorylase kinase

4. Debranching enzyme

5. Glucose-6-phosphatase

Choose the hormone whose secretion may be damaged at diabetes mellitus in person:

A. Cortisol

B. Progesterone

C. Growth hormone

D. Insulin*

E. Epinephrine

Which of the following statements about glycogen metabolism is true?

1. Cyclic AMP–activated protein kinase stimulates glycogen synthase

2. Glycogen phosphorylase kinase is activated by phosphorylation*

3. Glycogen phosphorylase b is inactivated by phosphorylation

4. Epinephrine and glucagon can low cAMP levels in cytoplasma thus stimulating glycogenolysis

5. Glycogen synthesis is stimulated by glucagon

Point out the main process maintaining the blood glucose level during fasting first 24 hours:

1. Glycolysis

2. Hexose monophosphate shunt

3. Glycogenolysis in the muscles

4. Glycogenolysis in the liver*

5. Gluconeogenesis in the muscles

A child is languid, apathetic. Liver is enlarged and liver biopsy revealed a significant amount of glycogen. Glucose concentration in the blood stream is below normal. What is the cause of low glucose levels:

1. Low {absent} activity of hexokinase

2. High activity of glycogen synthetase

3. Deficit of gene that is responsible for the synthesis of glucose 1-phosphate uridine transferase

4. High activity of glycogen phosphorylase in liver

5. Low {absent} activity of glucose 6-phosphatase*

A child has been diagnized for low blood glucose (hypoglycemia), enlarged liver (hepatomegaly), and excess fat deposition in the cheeks. A liver biopsy reveals excess glycogen in hepatocytes. There is hypothetically Pompe’s desease. Deficiency of which of the following enzymes might explain this phenotype?

1. Glucose 6-phosphatase

2. Glucosyl -4:6 transferase (branching enzyme)

3. Lysosomal alpha-1,4-glucosidase*

4. Alpha-1,4-galactosidase

5. Amylo alpha-1,6 glucosidase (debranching enzyme)

Point out the enzyme that breaks beta1→4 linkages in hyaluronic acid and other glycosaminoglycans?

A. Cellulase

B. Glycogen phosphorylase

C. Lactase

D. Hyaluronidase *

E. Glycogen synthase

Point out the enzyme whose deficiency can cause the Gierke's disease development:

A. Alpha-1,4-glycosidase

B. Amylo- 1,6 -glycosidase

C. Glycogen-branching enzyme

D. Glucose-6-phosphatase*

E. Glycogen phosphorylase

Which glycosaminoglycan is the most abundant in cartilage?

A. Heparan sulfate

B. Keratan sulfate

C. Chondroitin sulfate *

D. Hyaluronic acid

E. Dermatan sulfate

After meals blood glucose enters liver cells and is stored as glycogen, mainly. Which of the following compounds is the donor of new glucose residue in glycogen molecule?

1. UDP-glucose-1-phosphate

2. UDP-glucose*

3. UDP-glucose-6-phosphate

4. Glucose-6-phosphate

5. Glucose-4-phosphate

McArdle’s disease development causes muscle cramps and muscle fatigue with increased muscle glycogen in a patient. Which of the following enzymes is deficient?

1. Hepatic hexokinase

2. Muscle glycogen synthetase

3. Muscle glycogen phosphorylase*

4. Muscle hexokinase

5. Muscle debranching enzyme

Find out the pair of enzymes providing the reciprocal control of carbohydrate metabolic pathways:

1. Acetyl CoA carboxylase and pyruvate kinase

2. Hexokinase and glucose 6-phosphatase

3. Phosphohexose isomerase ang phosphotriose isomerase

4. Branching and debranching enzymes

5. Glycogen synthase and glycogen phosphorylase*

Insulin decreases the rate of gluconeogenesis by suppressing of one the following enzymes. Point out this enzyme:

1. Hexokinase

2. Phosphofructokinase

3. Pyruvate kinase

4. Glycogen synthase

5. Pyruvate carboxylase*

A liver biopsy has been made for child with hepatomegaly and mild fasting hypoglycemia. Hepatocytes contant shows the accumulation of glycogen granules with single glucose residues remaining at the branch points near the periphery of the granule. The most likely genetic disorder in this child is associated with the defect in:

A. Glycogen phosphorylase

B. Glucosyl -4:6 transferase (branching enzyme)

C. Phosphoglucomutase

D. Amylo alpha-1,6 glucosidase (debranching enzyme)*

E. Lysosomal alpha-1,4 glucosidase

Insulin stimulates all the processes listed below in adipocytes except:

1. Oxidative decarboxylation of pyruvate

2. Hexose monophosphate shunt

3. Transport of glucose through cell membrane

4. Catabolism of glucose

5. Glycogenolysis*

The most important substances as a source of blood glucose after 48 hours of starvation are:

1. Muscle and liver glycogen

2. Liver glucoseaminoglycans

3. Fructose and galactose

4. Amino acids*

5. Fructose

What hormone decreases the glucose concentration in the blood, if its value is more than 6.8 mM/L:

A. Thyroxin

B. Testosterone

C. Glucagon

D. Adrenalin

E. Insulin*

Choose the substance that may be the terminal product of glycogenolysis in muscles:

A. Glycogen

B. Glucose

C. Pyruvate

D. Fructose

E. Glucose-6-phosphate*

Point out the key enzyme of glycogen degradation in the liver:

А. Fructose-1,6-bisphosphatase

B. Glycogen Phosphorylase*

C. Glyceraldehyde-3-phosphatase

D. Glucose-6-phosphatase

E. Glucose oxidase

How does adrenalin influence the glucose level in the blood?

A. Increases, stimulating the glycogen destruction*

B. Decreases, stimulating the gluconeogenesis

C. Does not influence

D. Decreases, inhibiting the glycogen synthesis

Е. Decreases, inhibiting the glycolysis

Patient with diabetes mellitus experienced loss of consciousness and convulsions after an injection of insulin. What might be the result of biochemical blood analysis for concentration of glucose?

1. 3,3 mmole/L

2. 10 mmole/L

3. 8,0 mmole/L

4. 1, 5 mmole/L .*

5. 5,5 mmole/L

The investigation of the blood and urine of patient with diabetes mellitus confirmed the hyperglycemia and glucosuria states. Point the available value of glucose concentration in the blood plasma of this patient:

A. 2, 54 mmol/l

B. 3, 88 mmol/l

C. 9, 32 mmol/l*

D. 6, 55 mmol/l

E. 4, 89 mmol/l

Which of the following metabolites is found in glycogenolysis, glycolysis, and gluconeogenesis?

1. Galactose-1-phosphate

2. Glucose-6-phosphate*

3. Uridine diphosphoglucose

4. Fructose-6-phosphate

5. Uridine diphosphogalactose

Which of the following alterations would be expected to occur after a substantial breakfast?

1. Increased activity of pyruvate carboxylase

2. Decreased activity of glucokinase

3. Decreased rate of glycogenolysis*

4. Decreased rate of protein synthesis

5. Increased activity of phosphoenolpyruvate carboxykinase

Blood glucose levels cannot be augmented by mobilization of muscle glycogen due to lack of:

1. Glucose-6-phosphate dehydrogenase

2. Aldolase

3. Glucose-6-phosphatase*

4. Glucokinase

5. Hexokinase

The tissue with the highest glycogen content (mg/100g of tissue) is:

1. Liver*

2. Skeletal muscle

3. Kidney

4. Testes

5. Brain

Mucopolysaccharidoses are inherited storage diseases. They are caused by:

A. An increased rate of synthesis of proteoglycans

B. The synthesis of polysaccharides with an altered structure

C. Defects in the degradation of proteoglycans

D. The synthesis of abnormally small amounts of protein cores

E. All the proposed options are correct*

Glycogen polysaccharide is synthesized from the active form of glucose. The immediate donor of glucose residues during the glycogenesis is:

1. Glucose-3-phosphate

2. Glucose-6-phosphate

3. UDP-glucose*

4. Glucose-1-phosphate

5. ADP-glucose

Inherited disease, such as mucopolysaccharidosis, is manifested in metabolic disorders of connective tissue, bone and joint pathologies. The sign of this disease is the excessive urinary excretion of the following substance:

1. Lipids

2. Amino acids

3. Urea

4. Glycosaminoglycans *

5. Glucose

A 50-year old patient with food poisoning is on a drip of 10 % glucose solution. It does not provide the body with necessary energy only, but also performs the function of detoxification by the production of a metabolite that participates in the following conjugation reaction:

1. Glucuronidation *

2. Hydroxylation

3. Methylation

4. Sulfation

5. Glycosylation

What glycolytic enzyme is stimulated by insulin:

Glucose-6-phosphatase

Hexokinase*

Aldolase

Adenylate kinase

Phosphoglycerate kinase