Nucleus

nucleus

contains genetic library for the synthesis of nearly all cellular proteins

nuclear envelope

layer of two membranes that surrounds the nucleus of a cell

nuclear pores

structures in the nuclear envelope that allow passage of certain materials between the cell nucleus and the cytoplasm

nucleoli

Sites where ribosomes are assembled

chromatin

made of nucleosomes - clusters of 8 histone proteins connected by dna

condenses into chromosomes

protein synthesis

the formation of proteins by using information contained in DNA and carried by mRNA

exons

coding regions

introns

sequence of DNA that is not involved in coding for a protein

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

transcription

synthesis of an RNA molecule from a DNA template

translation

decoding of a mRNA message into a polypeptide chain