Clinical Biochemistry study questions – Unit 1 - Dr. Langer
What are some of the
goals in developing a clinical test?
What is the difference
between a false positive and a false negative?
What is a reference
interval in assessing clinical values?
What are the consequences
of using an inappropriate reference interval for a given population?
Define normal.
Describe the difference
between sensitivity and specificity in a clinical test.
Make sure you are
familiar with all of the basic concepts and terms introduced throughout the
course. Look up the terms in a medical dictionary, your textbook, a
biochemistry text or ask the instructor. The following questions are
provided to give you an idea of some of the basic concepts that you should
be familiar with.
Does a change in the
genotype necessarily result in a change in the phenotype?
If a person has two
normal alleles for a gene, does it mean that the sequences of these genes
are identical?
Understand the
relationship between mutations and how they might affect gene expression.
Define the following:
point mutation, deletion, addition, silent mutation, chromosomal
abnormality.
What is the main purpose
of the polymerase chain reaction?
What is an immune
complex?
Distinguish between a
monoclonal antibody and a polyclonal antibody.
What is the significance
of the major histocompatibility complex (MHC) of the mouse or the human
leukocyte antigen (HLA) locus in the human?
Which types of hormone will interact with cell surface receptors: steroid hormones or protein hormones.
1. Which compartments are considered when evaluating substances in the extracellular water compartment?
2. Which are the measured ions in the calculation of the anion gap? Give an example of an unmeasured anion.
3. What is colloid osmotic pressure?
4. Distinguish between filtration and reabsorption.
5. Discuss the forces taken into consideration when calculating the filtration pressure in a capillary bed.
6. The Gibbs Donnan Equilibrium can be used to describe the movement of ions between which compartments in the
body?
7. Describe the transport of ions by the Na+-K+ ATPase in the cell.
8. Describe the role of the hypothalamus in regulating extracellular water osmolarity and volume.
9. How does atrial natriuretic peptide affect sodium balance in the body?
10. Distinguish between sensible and insensible water loss.
11. Distinguish between hypernatremia, normonatremia and hyponatremia.
12. Describe the abnormality in SIADH (syndrome of inappropriate ADH secretion).
1. Why does a metabolically active tissue generate acid? Describe several metabolic reactions or pathways that
generate acid in a tissue.
2. Which acids accumulate in a person with uncontrolled diabetes? Why?
3. Why is it desirable to maintain a relatively constant blood pH? List several examples of biochemical mechanisms that
would be affected by a significant change in pH.
4. List the four important buffering systems in the body. Which one is most important in the urine?
5. Determine the ratio of bicarbonate to carbonic acid in a patient whose blood pH is 7.2. Use a pKa’ value of 6.1 and
write out the Henderson-Hasselbach equation. Is the patient acidotic or alkalotic?
6. Write out an equation describing the reactions in the bicarbonate buffering system. Indicate the enzyme and its site of
action in this reaction scheme.
7. How does hemoglobin carry CO2?
8. 2,3-DPG level is raised during exercise. Would you expect 2,3-DPG to raise or lower the affinity of hemoglobin for
oxygen?
9. Describe the action of the erythrocyte anion exchanger (Cl-/HCO3- exchanger).
10. Write out the Henderson-Hasselbach equation. Circle the term that changes when a patient has respiratory acidosis.
11. Describe the change in the anion gap in a patient with metabolic acidosis.
12. List the four categories of acid-base disorders. For each category, give one or two examples of a medical condition that
would lead to that disorder.
13. Why would intravenous bicarbonate be administered to a patient with aspirin poisoning?
1. List the main functions of the kidney.
2. Draw a nephron and label the various sections. In which regions are sodium and water reabsorbtion under hormonal
regulation?
3. Describe the counter-current mechanism in the kidney.
4. What is the GFR? What substances are analyzed in the measurement of the GFR and why?
5. Discuss normal glomerular filtration. What changes occur when the permeability of the glomerular basement membrane
increases in a disease state?
6. Describe the renin-anigiotensin-aldosterone system including:
--States that will cause increased renin levels
--An outline of the hormonal cascade
--Effects of angiotensin II
--Effects of aldosterone
--Sites that are drug targets in anti-hypertensive therapy
7. Why does a patient with congestive heart failure develop edema? Describe the multiple mechanisms involved in
affecting the patient’s sodium and water balance.
8. What is meant by the “renal plasma threshold for glucose?”
9. How does the kidney play a role in the regulation of the body’s acid-base balance?
10. What disorder develops when there is reduced proximal tubule reabsorption of bicarbonate?
11. Why are steroids used in treating a patient with Goodpasture’s disease?
12. Describe renal calculi. Give examples of substances found in renal calculi.
1. List the main functions of the liver.
2. What is the parenchymal cell of the liver?
3. Draw a liver lobule and label the various parts.
4. Write the reactions involved in glycogenesis and glycogenolysis. Always include the names of enzymes catalyzing
reactions.
5. Discuss the importance of the liver in supplying glucose to the body. What happens in patients with von Gierke’s
disease?
6. Write the reactions catalyzed by the two main transaminases in the liver. Always include the names of enzymes
catalyzing reactions.
7. Describe the route by which an alpha-amino group is transferred from an amino acid and eventually excreted via the
urea cycle.
8. Distinguish between bile acids and bile pigments.
9. What is kernicterus?
10. Discuss the mechanism by which the heme moiety in hemoglobin is removed from the body. Use example disorders to
| illustrate the various steps in bilirubin metabolism.
11. In addition to a hepatitis virus, exposure to which other things can cause hepatitis?
12. Discuss the biochemical defect in alpha 1-antitrypsin deficiency. Why do patients with alpha 1-antitrypsin deficiency
develop emphysema and liver cirrhosis? Propose several treatments for patients with alpha1-antitrypsin deficiency.