Cell structure Flashcards
What is the function of the nucleus?
The nucleus contains the organisms hereditary material and controls the cells activities.
The nucleus acts as the control centre of the cell through the production of mRNA and tRNA and hence protein synthesis.
The nucleus manufactures rRNA and ribosomes.
What are the 5 parts to the nucleus?
nuclear envelope,
nuclear pores,
nucleoplasm,
chromosomes,
nucleolus.
What is the nuclear envelope?
The nuclear envelope is a double membrane that surrounds the nucleus.
Its outer membrane is continuous with the ER of the cell and often contains ribosomes on its surfaces.
What does the nuclear envelope control?
The nuclear envelope controls the entry and exit of materials in and out of the nucleus and contains the reactions taking place within it.
What do the nuclear pores do?
They allow the passage of large molecules such as mRNA out of the nucleus.
How many nuclear pores are there and how big are they?
There are typically 3000 pores in each nucleus.
Each pore is around 40-100nm in diameter.
What is the nucleoplasm?
A granular, jelly-like material that makes up the bulk of the nucleus.
What do chromosomes consist of?
A protein-bound linear DNA.
What is the nucleolus?
A small spherical region within the nucleoplasm. It manufactures tRNA and assembles the ribosome.
How many nucleolus’ are there in a nucleus?
There may be more than 1 nucleolus in a nucleus.
