Although this chapter is relevant to what you are learning over the next couple of weeks, I am only concerned with the following sections:
-
- Erythrocyte Metabolism
- The Red Blood Cell Membrane.
- The Biochemistry of Erythrocytes and Other Blood Cells. Lippincott® Illustrated Reviews: Biochemistry, 8e. Medical Education: Health Library.
- You have seen part of this chapter earlier in 501. Please see the sections on Globular Hemeproteins and Globin Gene Organization for this session:
- The "Red Cell Membrane Disorders" section is all you need to glance at for this session. And when I say "glance," I mean that you should briefly look it over—perhaps after class, when you'll see what disorders I want you to focus on:
Overview
Today we will explore the metabolic pathways in the red blood cell that maintain the RBC membrane and hemoglobin molecule. Most of this material builds off of sessions that we discussed earlier in FMS 501.
Describe the structure and properties of the red cell membrane and explain how defects in these structures induce specific hematological disease states
It’s important to understand the characteristics of an erythrocyte at the membrane level. There are a number of proteins that help the cell with flexibility and durability for it to flow through a capillary bed. Listed below are a few of the proteins that are important in red blood cells.
| Band | Protein | Red blood cell disorder |
|---|---|---|
|
1 |
alpha-Spectrin
|
Hereditary spherocytosis Hereditary elliptocytosis |
|
2 |
beta-Spectrin
|
Hereditary spherocytosis Hereditary elliptocytosis |
|
2.1 |
Ankyrin |
Hereditary spherocytosis
|
|
2.9 |
alpha-Adducin |
No hematologic abnormalities reported
|
|
2.9 |
beta-Adducin
|
No hematologic abnormalities reported
|
|
3 |
Anion exchanger-1
|
Hereditary spherocytosis Hereditary ovalocytosis Acanthocytosis and echinocytosis |
|
4.1 |
Protein 4.1
|
Hereditary elliptocytosis |
|
4.2 |
Protein 4.2 |
Hereditary spherocytosis |
|
4.9
|
p55 |
No hematologic abnormalities reported
|
|
4.9 |
Dematin |
No hematologic abnormalities reported
|
|
5 |
beta-Actin
|
No hematologic abnormalities reported
|
|
5 |
Tropomodulin |
No hematologic abnormalities reported
|
|
6 |
G3PD |
No hematologic abnormalities reported
|
|
7 |
Stomatin |
Hereditary stomatocytosis
|
|
7 |
Tropomyosin |
No hematologic abnormalities reported
|
|
PAS-1 |
Glycophorin A
|
Hereditary elliptocytosis
|
|
PAS-2 |
Glycophorin C
|
Hereditary elliptocytosis
|
|
PAS-3 |
Glycophorin B
|
No hematologic abnormalities reported
|
|
|
Glycophorin D
|
No hematologic abnormalities reported
|
|
|
Glycophorin E
|
No hematologic abnormalities reported
|
Describe hemoglobin structure, synthesis, and function regarding the hemoglobin oxygen dissociation curve and the factors responsible for the shift of the curve
Osmosis has a very good video on Oxygen saturation curves. This is a very high-yield topic to know.
We discussed the hemoglobin structure back in 501. Shown below is the globin gene structure and the different combinations that can be made.
Explain the mechanism and outcome of the oxidation of heme iron with focus on the hereditary and acquired methemoglobinemia
Another high-yield item to know, and Osmosis has a video on it.
Describe the role of glycolysis and the pentose phosphate pathway in erythrocytes
We’ve been over both of these topics before. When we discussed the PPP back in carbs, there was a learning goal on glucose 6-phosphate dehydrogenase deficiency (Osmosis video from before). We discussed anaerobic metabolism during the Glycolysis session (i.e., RBCs, since they have no mitochondria) and how 2,3-BPG (aka 2,3-DPG).