Nuclear Structure and Blood Types Summary

Nuclear Structure

  • Nuclear Envelope Components:

    • Inner and outer membranes.

    • Nuclear pores facilitate transport.

    • Nucleoplasm contains chromatin and nucleoli.

  • Nuclear Pore Complex:

    • Composed of nucleoporins with FG-repeat domains.

    • Allows bidirectional movement of molecules between nucleus and cytoplasm.

    • Structure includes:

    • Central channel

    • Cytoplasmic and nuclear rings

    • Nuclear basket. I

  • Chromatin Structure:

    • Composed of DNA wrapped around histones (octamer).

    • Higher-order structures include nucleosome filaments and 30 nm fiber.

    • Distinction between euchromatin (active) and heterochromatin (inactive).

Blood Types

  • Classification:

    • Four main blood types: A, B, AB, O, differentiated by presence of antigens on RBCs.

    • Antigens determine compatibility (e.g., Type O universal donor, Type AB+ universal recipient).

  • Glycosyl Transferases Role:

    • Enzymes that modify the O antigen to produce A or B blood types.

    • Type A: N-acetyl galactosamine addition.

    • Type B: Galactose addition.

    • Type AB: Mixture of modifications from A and B.