Hema Lec 3 (Chapter 6,7,8) -

Anaerobic Glycolysis (Embden-Meyerhof Pathway)

The process by which RBCs generate energy without oxygen by breaking down glucose into pyruvate and producing ATP.

Hexose Monophosphate Pathway (HMP)

A metabolic pathway that produces NADPH, protecting RBCs from oxidative damage.

Glucose-6-Phosphate Dehydrogenase (G6PD)

An enzyme crucial for NADPH production. Its deficiency can lead to hemolysis.

Methemoglobin

Hemoglobin in which iron is oxidized to the ferric state, making it unable to carry oxygen. The methemoglobin reductase pathway converts it back to hemoglobin.

2,3-Biphosphoglycerate (2,3-BPG)

A molecule that helps release oxygen from hemoglobin to tissues by competing with oxygen for binding sites on hemoglobin.

RBC Deformability

The ability of red blood cells to stretch and pass through small capillaries without damage.

Phospholipids

The main components of the RBC membrane, forming a bilayer that acts as a barrier between the cell's interior and the external environment.

Phosphatidylcholine & Sphingomyelin

Phospholipids that make up most of the outer layer of the RBC membrane.

Phosphatidylserine & Phosphatidylethanolamine

Phospholipids that make up most of the inner layer of the RBC membrane.

Spectrin

A cytoskeletal protein that provides horizontal stability to the RBC membrane by forming a lattice structure.

Methemoglobin

Hemoglobin where the iron has been oxidized to the ferric state, making it unable to bind oxygen.

Hemoglobin A (HbA)

The major adult form of hemoglobin composed of two alpha and two beta chains.

Glycated Hemoglobin (HbA1c)

Hemoglobin with glucose attached, used to monitor long-term glucose levels.

Heme

A component of hemoglobin made of a ring structure (protoporphyrin IX) with ferrous iron in the center.

Quaternary Structure

The complete structure of a hemoglobin molecule with four heme groups and four polypeptide chains.

2,3-BPG (2,3-Biphosphoglycerate)

A molecule that regulates oxygen delivery by competing with oxygen for binding to hemoglobin.

Na⁺/K⁺-ATPase

An enzyme that helps maintain osmotic balance by pumping sodium out of the RBC and potassium in.

Hb A

The main adult hemoglobin, consisting of 2 alpha and 2 beta chains.

Hb A2

A minor form of hemoglobin in adults, consisting of 2 alpha and 2 delta chains, making up less than 3.5% of total Hb.

Hb F

Fetal hemoglobin with 2 alpha and 2 gamma chains, higher oxygen affinity compared to Hb A.

ALA Synthase

The enzyme that catalyzes the rate-limiting step in heme biosynthesis.

Erythropoietin (EPO)

A hormone produced by the kidneys that increases RBC production in response to low oxygen levels.

Oxygen Dissociation Curve

A graph that shows how Hb's oxygen-binding affinity changes with oxygen pressure.

Bohr Effect

The release of oxygen from Hb in response to increased CO₂ and H⁺ levels in tissues.

Methemoglobin (MetHb)

Hemoglobin with iron in the ferric state, unable to carry oxygen.

Sulfhemoglobin

Hemoglobin irreversibly altered by sulfur compounds, causing a greenish tint to the blood.

Carboxyhemoglobin (COHb)

Hemoglobin bound to carbon monoxide, preventing oxygen transport.

Functional Iron

Iron that is currently being used in hemoglobin, myoglobin, and cytochromes.

Storage Iron

Iron stored in the body, mainly in macrophages and the liver, as ferritin.

Transport Iron

Iron being transported in the blood, bound to transferrin.

Ferrous Iron (Fe²⁺)

The reduced form of iron, more easily absorbed in the intestines.

Ferric Iron (Fe³⁺)

The oxidized form of iron, required for transport in the blood.

Ferroportin

The protein responsible for exporting iron from cells.

Hepcidin

A hormone that regulates iron export by binding to and inactivating ferroportin.

Transferrin

The protein that transports iron in the blood.

Ferritin

The storage form of iron within cells.

Serum Iron

The level of iron in the bloodstream.

Total Iron-Binding Capacity (TIBC)

The blood's ability to bind iron, related to the amount of transferrin available.

Prussian Blue Staining

A technique used to identify iron deposits in tissues.

Soluble Transferrin Receptor (sTfR)

A marker indicating the body's demand for iron.