Learning Objectives 3

Learning Outcomes 3

Gas Transport

1. Describe how the cooperative binding of oxygen by hemoglobin makes it a better oxygen transporter.

2. Define the "R" (relaxed) and "T" (tense) states of hemoglobin.

3. Describe the relationship of the Bohr effect to oxygen binding by hemoglobin and explain the physiological significance of this effect.

4. Discuss the effect of carbon dioxide (CO₂) on hemoglobin affinity for oxygen and the physiological relevance of this effect.

5. Explain the effect of 2,3-bisphosphoglycerate (BPG) on hemoglobin affinity for oxygen and how it facilitates oxygen release to tissues.

6. Explain why the low affinity of fetal hemoglobin for BPG is beneficial to the fetus.

Introduction to Antibodies and Antigens

1. Diagram the basic structure common to immunoglobulins.

2. Define the following terms related to immunoglobulin structure: heavy chain, light chain, constant region, variable region, hinge region, Fab fragment, Fc fragment and complementarity-determining regions (CDRs).

3. Describe the different forces involved in the binding of an antibody to its antigen and define the term hapten.

Enzymes: Catalysis and Kinetics

1. Describe the following terms associated with enzymes: catalysis, substrate, reaction specificity, rate-limiting step, coenzyme and prosthetic group.

2. Define the following six types of enzyme reactions: transferase, hydrolase, oxidoreductase, lyase, ligase and isomerase.

3. Define the following terms related to the energy of enzyme reactions: transition state, energy of activation, exergonic, endergonic and free energy change.

4. Discuss the concepts of substrate affinity, K_m and apparent K_m.

5. Use the Lineweaver-Burke plot to demonstrate V_max, K_m, competitive inhibition and non-competitive inhibition.

Case Study 2

Define the structure of lactose and discuss how a lactase deficiency can provoke physiological symptoms.

Enzymes: Isozymes and Regulation

1. Define isozyme and nonfunctional plasma enzyme and discuss the importance of nonfunctional plasma enzymes as a diagnostic tool.

2. Identify the brain, muscle, heart and liver isozyme patterns for creatine phosphokinase and lactate dehydrogenase.

3. Describe how creatine phosphokinase and lactate dehydrogenase can be used in the diagnosis of myocardial infarction.

4. Explain why a combined analysis of plasma glutamyl transpeptidase and alanine aminotransferase is desirable for diagnosing hepatitis in a patient.

5. Define the following types of regulation of enzyme activity: substrate availability, allostery, post-translational modification, interactions with control proteins and zymogens.

6. List 6 ways that proteins can undergo post-translational modification.

7. Identify the 3 amino acids which can undergo phosphorylation.

Case Study

Diagram the time course for the appearance in serum of creatine kinase, lactate dehydrogenase and aspartate amino transferase following a myocardial infarction.

Enzyme Mechanisms-Serine Proteases

1. Describe the general roles played by the serine, histidine and aspartate residues in the active site of chymotrypsin.

2. Explain why histidine is found in the active site of many diverse proteases.

3. Diagram the catalytic mechanism of chymotrypsin, identifying the two transition states.

4. Give two examples of other serine proteases and their general physiological role.

5. Define the term proenzyme and give an example of a physiological role for proenzymes.