Nuclear membrane (Demonstrations)

Cell And Molecular Biology

1. CELL AND MOLECULAR BIOLOGY (BIO 140) Topic: Nuclear Membrane

2. NUCLEAR MEMBRANE PREPARED BY: MELENCION, MARBEN APOSTOL

3. Nuclear Membrane Also known as the nuclear envelope . Is the double lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells . Consists of two lipid bilayers Inner nuclear membrane Outer nuclear membrane

4. All eukaryotic cells (those found in animals, plants, protists, and fungi) have a control center called the Nucleus

5. In Nucleus, this is where the genetic material, or DNA is stored. Surrounding every nucleus is a double-layered membrane called the nuclear membrane or nuclear envelope . This membrane separates the nucleoplasm , or fluid inside the nucleus , from the cytoplasm, or the fluid outside the nucleus.

6. Outer Nuclear Membrane The outer nuclear membrane is also contiguous with the endoplasmic reticulum. While it is physically linked, the outer nuclear membrane contains various proteins found in far higher concentrations than the endoplasmic reticulum.

7. Inner Nuclear Membrane The inner nuclear membrane encloses the nucleoplasm . It is connected to the other membrane by nuclear pores which penetrate the membranes. While the two membranes and the endoplasmic reticulum are linked, proteins embedded in the membranes tend to stay put rather than dispersing across the continuum.

8. Each membrane is composed of Phospholipids arranged in a bilayer. The Outer Nuclear Membrane is continuous with the rough endoplasmic reticulum , an organelle important in making and transporting proteins.

9. The space between the membrane is called the perinuclear space , a region contiguous with the lumen (inside) of the endoplasmic curriculum.

10. Both the rough endoplasmic reticulum and outer nuclear membrane are covered in ribosomes , which are actual sites of protein synthesis.

11. Attached to the Inner Nuclear Membrane on the nucleoplasm side is the nuclear lamina , a sheet of proteins that provides support for and strengthens the nuclear envelope. Also, it attaches to and anchors chromatin , loosely arranged DNA and protein.

12. FUNCTIONS OF NUCLEAR MEMBRANE

13. The Nuclear membrane keeps your DNA inside the nucleus to protect it from surrounding the substances in the cytoplasm. Additionally, the Nuclear envelope can regulate what materials enter or exit the nucleus. Anything that needs to pass between the nucleoplasm and the cytoplasm can only do so through holes in the membrane called Nuclear Pores .

14. Proteins lining the nuclear pores will recognize these labels or tags and let the molecular cross. There are two Kinds of tags: Nuclear Localization signal Nuclear Export signal

15. Nuclear pores only allow very small molecules, ions, or proteins to freely move into or out of the nucleus. Any large molecules that needs to cross the nuclear membrane must have the appropriate levels.

16. ADDITIONAL IDEAS Please listen...