Nuclear envelope

Definition

The nuclear envelope is a double-membrane structure that encases the nucleus in eukaryotic cells, separating it from the cytoplasm. It regulates the passage of macromolecules like RNA and proteins through nuclear pores.

5 Must Know Facts For Your Next Test

1. The nuclear envelope consists of an inner and outer membrane, each with distinct functions.
2. Nuclear pores embedded in the nuclear envelope control the movement of substances between the nucleus and cytoplasm.
3. The outer membrane of the nuclear envelope is continuous with the endoplasmic reticulum.
4. The perinuclear space exists between the inner and outer membranes of the nuclear envelope.
5. During cell division, the nuclear envelope disassembles and reassembles to allow chromosome segregation.

Review Questions

• What are the main components of the nuclear envelope?
• How do nuclear pores function in relation to the nuclear envelope?
• What happens to the nuclear envelope during cell division?

Related terms

Chromatin: Complex of DNA and proteins within the nucleus that condenses to form chromosomes during cell division.

Endoplasmic Reticulum: A network of membranous tubules within eukaryotic cells involved in protein and lipid synthesis.

Nucleolus: A dense region within the nucleus where ribosomal RNA (rRNA) synthesis occurs.