(Cell Bio) Ch 10

Nucleus

Largest organelle

Houses the DNA

Allows for:

Organization

Regulation of transcription

Nuclear Structure

Envelope

Membrane

Lamina

Pores

Envelope’s 2 components

1. Double Phospholipid Bilayer (membrane)

2. lamina

Main function of nuclear Envelope

Housing

Nuclear Envelope entry/exit

Nuclear pores

Nuclear Membrane

1. Outer membrane: contiguous with ER

2. Inner Membrane

Perinuclear space in the Nuclear Membrane

space between inner and outer membrane

Nuclear Membrane composition

phospholipids

Nuclear lamina

protein mesh directly under inner membrane

Nuclear Lamina Function

-Support nuclear membranes

-Shape

-Organization of DNA

Composition of Nuclear Lamina

cross linked proteins (hydrophilic) with lipid modifications (anchor)

Lamin polypeptides

-Intermediate filaments

-Dimerize

Bind to:

-Inner Nuclear Membrane

-Chromatin

-Cytoskeleton

Dimerize

two individual molecules (often proteins or receptors) join together to form a pair.

Nuclear Pore Complex

Only way in or out of the nucleus

Nucleoporins

proteins that go through both layers of the nuclear membrane