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0F SCIEITCE FIFID TECHI‘IOLOGY

Faculty of Health and Applied Sciences

Department of Health Sciences

QUALIFICATION: BACHELOR of MEDICAL LABORATORY SCIENCE

QUALIFICATION CODE: 08BMLS LEVEL: 6

COURSE: CLINICAL CHEMISTRY 28 COURSE CODE: CLC621S

DATE: January 2018 SESSION: Theory

DURATION: 3Hours MARKS: 110

SECOND OPPORTUNITY EXAMINATION QUESTION PAPER

EXAMINER(S) Mrs C de Waal-Miller

MODERATOR: Mr. M. Mukesi

INSTRUCTIONS

Answer all questions.

Please write neatly and legibly.Do not use the left side margin of the exam paper. This must be allowed for the examiner.

No books, notes and other additional aids are allowed.

Mark all answers clearly with their respective question numbers..U‘P‘P’NI“Permissable material

Non programmable calculator is allowed.

THIS QUESTION PAPER CONSISTS OF _9_ PAGES (Including this front page)

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nnmlBlH UFIIVERSITY

OF SCIENCE HHD TECHHOLOGY

Faculty of Health and Applied Sciences

Department of Health Sciences

QUALIFICATION: BACHELOR of MEDICAL LABORATORY SCIENCE

QUALIFICATION CODE: OBBMLS LEVEL: 6

COURSE: CLINICAL CHEMISTRY 23 COURSE CODE: CLC621$

DATE: January 2018 SESSION: Theory

DURATION: 3 Hours MARKS: 110

SECOND OPPORTUNITY EXAMINATION MEMORANDUM

EXAMINER(S) Mrs C de Waal-Miller

MODERATOR; Mr. M. Mukesi

INSTRUCTIONS

Answer all questions.

Please write neatly and legibly.

No books, notes and other additional aids are allowed.PIPS'UNI‘ Do not use the left side margin of the exam paper. This must be allowed for the examiner.

Mark all answers clearly with their respective question numbers.

Permissable material

Non programmable calculator is allowed.

THIS QUESTION PAPER CONSISTS OF _9_ PAGES (Including this front page)

CLC621S Examination Second opportunity Jan 2018

SECTION 1 {42 marks}

QUESTION 1 [17]

Insert the correct missing word. Write on the number of the question and next to it the missing word.

1.1. Man-made chemically induced fatty acids are called (1)

1.2. are a group of polyunsaturated fatty acids that stimulate uterine contraction (l)and influence platelet aggregation.

1.3. Lack of the trace metal can lead to defective production of (1)

spermatozoa.

1.4. Since the trace metal is a constituent of Vitamin B 12, a lack thereof can (1)lead to Megaloblastic anaemia.

1.5. Acquired or secondary porphyria can be caused by poisoning. (1)

1.6. A visual characteristic of many porphyrins is under UV light. (1)

1.7. are involved in three steps of porphyrin and haem synthesis. (1)

1.8. Of the non-protein nitrogen substances only is not dependent on kidney (1)function.

1.9. method is used for routine quantitation of total protein. (1)

1.10. In zero-order kinetics, the reaction rate is dependent on . (l)

1.11. The CK isoenzyme isolated from heart is called (1)

1.12. The enzyme that is most susceptible to the effects of haemolysis and freezing (1)

temperatures is

1.13. A laboratory finding of equal or above for fasting glucose in indicative of (1)diabetes.

1.14. The element content of sets proteins apart from carbohydrates and lipids, (1)which do not contain this element.

1.15. An important energy source in RBC is (1)

1.16. Monoclonal increases of is consistent with multiple myeloma and (1)Waldenstrom's macroglobulinemia.

1.17. is an integral part of cytochrome and other respiratory enzymes. (1)

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CLC621$ Examination Second opportunity Jan 2018

QUESTION 2 [25]

Select the appropriate / correct phrase / word / number to best describe the statement given. Write

only the number of the question and the letter of the statement / word.

2.1. Which of the following statements concerning Chylomicrons is false? (1)

A) This lipoprotein is produced in the intestinal mucosa

B) Primary function is to carry dietary (exogenous) lipids to the liver

C) The major lipid transported by this lipoprotein is cholesterol

D) Remains at the origin during lipoprotein electrophoresis

E) None of the above

2.2. The most likely cause for serum/plasma to appear "milky" is the presence of: (1)

A) VLDL

B) LDL

C) HDL

D) Chylomicrons

E) Only (A) and (B)

2.3. To overcome a competitive inhibitor in an enzyme reaction; (1)

A) Add more substrate

B) Add more enzyme

C) Add an activator

D) Add a co-enzyme

E) Only (A) and (D)

2.4. Common clinical laboratory methods for the measurement of serum albumin are based on the

properties of albumin as a/an: (1)

A) Enzyme

B) Antibody

C) Glycoprotein

D) Binding protein

E) Homogeneous protein

2.5. A glycoprotein that binds with haemoglobin to facilitate the removal of haemoglobin by the

reticuloendothelial system is: (1)

A) Haptoglobin

B) Ceruloplasmin

C) Transferrin

D) Haemopexin

E) C-reactive protein

2.6. The acute phase reactant protein that also inhibits proteolysis and has the highest concentration

within its globulin fraction is: (1)

A) C-reactive protein

B) Haptoglobin

C) AlphaZ-macroglobulin

D) Alphal-antichymotrypsinE) Alphal—antitrypsin

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CLC621S Examination Second opportunity Jan 2018

2.7. All of the following statements about partially compensated respiratory alkalosis are true EXCEPT: (1)

A) The pH is slightly higher than normal

B) pCOz is lower than normal

C) HC03 is lower than normal

D) Hypoventilation is the causative defect

E) Renal reabsorption of HC03 is decreased

2.8. Metabolic acidosis is described as a(n): (1)

A) increase in HC03 and pCOz with a decreased pH

B) Decrease in HCOs with an increased pH

C) increase in HCOg with an increased pH

D) Decrease in HC03 and pCOz with a decreased pH

E) None of the above

2.9. insulin may be described by all of the following EXCEPT: (1)

A) Synthesized from proinsulin

B) Synthesized by beta cells in the pancreas

C) Active in its C-peptide form

D) Two-chain polypeptide

E) Combines with insulin receptors

2.10. Which one of the following statements may be associated with the activity of insulin? (1)

A) increases blood glucose levels

B) Decreases glucose uptake by muscle and fat cells

C) Decreases cell membrane permeability to glucose

D) Stimulates release of hepatic glucose into the blood

E) Stimulates glycogenesis in the liver

2.11. Glycation of glomerular basement membranes and capillaries is the main nephropathiceffect from: (1)

A) Renal arteriosclerosis

B) Diabetes meilitus

C) Systemic lupus erythematosus

D) Glomerulonephritis

E) Hepatitis

2.12. What is the percentage of serum calcium that is ionized (Ca*)? (1)

A) 30%

B) 45%

C) 60%

D) 80%

E) 35%

2.13. Which of the following steps is NOT necessary in methods for iron determination? (1)

A) Reduction of Fe+3 to Fe+2

8) Protein precipitation

C) Colour formation

D) Release of Fe from transferrin

E) Only (A) and (D)

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CLC621S Examination Second opportunity Jan 2018

2.14. Blood specimens drawn early in the morning are recommended for measuring serum iron and TIBC

because: (1)

A) Most people's diet is rich in iron

B) Iron exhibits a diurnal cyclic variation

C) Iron in serum goes into the cells after a meal

D) The premise is incorrect; iron specimens do not need to be fasting

E) Iron is excreted later in the day

2.15. A urine screening test for porphobilinogen is positive. The MOST likely disease state is: (1)

A) Lead poisoning

B) Porphyria cutanea tarda

C) Acute porphyria attack

D) Erythrocytic protoporphyria

E) Mercury poisoning

2.16. Zinc protoporphyrin or free erythrocyte protoporphyrin measurements are useful to assess blood

concentration of: (1)

A) Lead

B) Mercury

C) Arsenic

D) Beryllium

E) All of the above

2.17. Which of the following enzyme tests is most affected by "haemolysis? (1)

A) Creatine kinase

B) Gamma glutamyl transferase

C) Lactate dehydrogenase

D) Alkaline phosphatase

E) G-6-PD

2.18. The preferred collection tube for preservation of glucose is: (1)

A) Calcium oxalate

B) Sodiumfluoride

C) Lithium heparin

D) Sodium citrate

E) EDTA

2.19. The following is NOT an Aminoacidopathy (1)

A) Maple Syrup Urine Disease

B) Homocystinuria

C) Ceruloplasmuria

D) Cystinuria

E) Albinism

2.20. The following is NOT a function of proteins. (1)

A) Transporters of smaller molecules

B) Hormone receptors

C) Part of phosphate buffering system

D) Enzyme catalysts

E) Provision of clotting factors

5 of 9 pages

CLC621$ Examination Second opportunity Jan 2018

2.21. The most frequent cause of hypermagnesemia is: (1)

A) Hypokalaemia

B) Acute or chronic renal failure

C) Tetany

D) Digitalis toxicity

E) Excessive intake of magnesium

2.22. The following condition will not be seen in patients with increased uric acid. (1)

A) Polycythemia

B) Leukaemia

C) Multiple myeloma

D) Lesh-Nyhan syndrome

E) Defective renal tubular re-absorption

2.23. Enzyme reactions are increased by increasing temperatures until they reach the point of

denaturation at: (1)

A) 50 — 60 C

B) 25 — 35°

c

C) 100°

C

D) 37 °C

E) >40°

C

2.24. One ofthe following is NOT a primary cardiac marker: (1)

A) CKMB

B) BNP

C) Myoglobin

D) AST

E) Hs—CRP

2.25. A factor other than average glucose levels that determines the glycosylated haemoglobin

level is: (1)

A) Serum ketone levels

B) Red blood cell life span

C) Ascorbic acid intake

D) Increased triglyceride levels

E) Elevated amylase levels

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CLC621$ Examination Second opportunity Jan 2018

SECTION B {28 marks}

QUESTION 3 [12]

3.1 Explain the role of ADH and aldosterone in regulation of acid-base balance. (4)

3.2 List the most common method in the laboratory to determine the concentration of sodium in serum.

(1)3.3 Mention the common cause of false elevated potassium in the laboratory and give 3 reasons

regarding the specimen handling that can cause the false high readings of potassium in the

laboratory. (4)

3.4 Briefly discuss collection of the Blood Gas specimen and precautions in handling of the specimen.

(6 x 1/2 = 3 )

QUESTION 4 [16]

4.1 Explain what is meant by ”osmolal gap”. (2)

4.2 State the formula for the calculated osmolality. (3)

4.3 Give a likely explanation for a delta Osmo of: (3)

A) -5

B) 5

C) 50

4.4 Give two (2) reasons for each of the following: (8)(A) Decreased serum osmolality

(B) Increased serum osmolality

(C) Decreased urine osmolality

(D) Increased urine osmolality

SECTION C {40 marks}

QUESTION 5 [28]

A lipid profile analysis on a 51 y/o male complaining of abdominal pain and vomiting after meals was as

follows:

Total cholesterol 9.1 mmol/L

Triglyceride 7.35 mmol/LHDL 0.65 mmol/L (0.78-1.68 mmol/L)

5.1. Calculate the LDL. (3)

5.2 Is the LDL level normal? State the normal or reference values of lipids. (5)

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CLC621S Examination Second opportunity Jan 2018

5.3 if chylomicrons are present in the sample, describe the appearance of the serum sample stored

at 2—8°C. (2)

5.4 If pancreatitis is suspected on this man, what enzyme levels would be beneficial? (2)

5.5 Indicate the primary lipid transported by each of the following lipoproteins: (4 X 2 = 8)

5.6 Cholesterol is excreted from the body primarily in what form? (1)

5.7 The patient rigorously followed a low-cholesterol diet, but his serum cholesterol was still increased

several months later. Why? (2)

5.8 What type of specimen collection is preferred for cholesterol analysis? (1)

5.9 Which of the two substances, cholesterol of triglycerides is most affected by diet? (1)

5.10 List 3 risk indicators for metabolic syndrome. (3)

QUESTION 6 [4]

A 52 year old male was admitted to the hospital with a chronic productive cough and shortness of breath

accompanied by wheezing. The patient had a history of smoking 2 packs of cigarettes a day for the past 30

years.

Arterial Gases: pH— normal

pCOz— increased

HC03 — increased

Electrophoresis g/L g/LAlbumin 38 (34-54)

Alpha 1 1 (3 - 5)

Alpha 2 5 (5—9)Beta 8 (6—11)Gamma 14 (8—15)

6.1 Based on the electrophoresis scan, what specific protein deficiency is suspected? (1)

6.2 Patient history and lab data suggest what disease? (1)

6.3. What acid —base disorder would be found in this condition? (1)

6.4 What mechanism would the body use to compensate for this condition? (1)

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CLC621$ Examination Second opportunity Jan 2018

QUESTION 7 [8]

A 38 year old man was admitted to the hospital. He had a 15 year history of alcoholism. His blood sample

was taken and submitted to the lab.

The following results were obtained from a patient’s blood sample.

Serum Sodium 136 (135 —147 mmol/L)Serum Potassium 3.9 (3.8 - 5.5 mmol/L)Serum Chloride 99 (100 -109 mmol/L)Total C02 17.3 (18 - 29 mmol/L)Serum amylase 423 (25-125 U/L)

Triglycerides 5.6 (up to 0.23 mmol/L)

7.1 Calculate the anion gap (AG). (4)

7.2 Evaluate the result and explain the possible reasons for that result. (3)

7.3 State the normal range for the anion gap. (1)

TOTAL MARKS 110

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