Biochemistry of blood, heme biosynthesis and degradation

Biochemistry of blood. Heme biosynthesis and degradation.

Composition of blood

plasma

erythrocytes

Leucocytes and platelets

Blood performs three major functions: transport through the body of

oxygen and carbon dioxide food molecules (glucose, lipids, amino acids) ions (e.g., Na+, Ca2+, HCO3−) wastes (e.g., urea) hormones

defense of the body against infections and other foreign materials. All the WBCs participate in these defenses.

Homeostatic functions- heat- water- salt balance- Acid – base balance- osmosis- blood clotting- formation of hormonoids

Red Blood Cells (erythrocytes)

The most numerous type in the blood.

•Features:•The erythrocytes doesn’t contain nucleus, chromatine•The erythrocytes doesn’t contain mytochondrias, thus АТP producing due to the anaerobic glycolisis till to the lactate (90%).•The glycolisis has features. During it the 2,3 BPG will be produced, not 1,3 BPG. This compound need for joining О2 to hemoglobin: low concentration of 2,3 BPG will increase the affinity hemoglobin (Нв) to О2.• The PPP is the main path for producing of reductive equivalents NADPН2 for taking part in glycolisis

Red blood cells are responsible for the

transport of oxygen and carbon dioxide. In adult humans the

hemoglobin (Hb) molecule consists of four polypeptides: two alpha (α) chains of

141 amino acids and two beta (β) chains of 146

amino acids Each of these is attached the

prosthetic group heme. There is one atom of iron at

the center of each heme. One molecule of oxygen can

bind to each heme. The reaction is reversible.

At norm it 65-85 g/l of proteins. In newborn it less concentration. Albumins is 35-50 g/l. In newborn it less concentration. Globulins are:α1 globulins – 1-4 g/lα2 globulins – 4-8 g/lβ globulins – 6-12 g/l γ globulins – 8-16 g/l

Concentration of γ globulins is higher in newborn.Fibrinogen is 2-4 g/l.

portal vein

hepatic artery

bile duct

sinusoids

bile canaliculi

central vein

Preventing blood loss