Information on a Cell Nucleus

All living organisms on our planet are comprised of the microscopic building blocks of life called cells. A cell is the smallest unit of an organism that can carry on the activities of life. These activities include maintaining homeostasis and regulating metabolism, reproduction and heredity. Cells have small organelles within them that each carry out a specific duty to ensure the organism thrives, and all of these organelles are ultimately controlled by the cell nucleus.

Function

• The most important organelle is the nucleus because it is the "brain" of the cell. The nucleus oversees all cell activity by storing and copying the genetic information that is used in order to make proteins, which in turn control all critical chemical reactions within the cell.

Storage of Genetic Information

• Genetic information comes in the form of deoxyribonucleic acid (DNA). The DNA in the nucleus is found in the form of chromatin (long, thin strands) during most of the cell cycle since the genetic information can be easily read. However, DNA is found in the form of chromosomes (densely packed and wrapped around proteins) when the cell is dividing.

Nucleolus

• The nucleolus is a subnuclear body found inside the nucleus and is responsible for making RNA and proteins. Its main functions are to assemble ribosomes and synthesize rRNA.

The Relationship Between the Nucleus and the Cytoplasm

• There is a limit as to how quickly the genetic information within a cell can be copied in the nucleus, moved into the cytoplasm (the body of the cell within the cell membrane), and ultimately used to make proteins. Therefore, if the cell were to get too large, the information for making proteins would not be able to reach the outer edges of the cell, and necessary chemical reactions would not take place.

Nuclear Envelope

• The nuclear envelope is a double lipid bilayer that surrounds the nucleus. Its main function is to physically separate the cell's genetic information from the rest of the cell.