Nucleus

Nuclear Envelope

2 lipid bilayers with a perinuclear space in between that separates the nucleus from the rest of the cell

Nuclear pores

protein channels that span the nuclear envelope and allow transport of materials between the nucleus and cytosol

Nuclear Lamina

intermediate filament proteins that give structural support to the nucleus

heterochromatin

spots of chromatin that are more condensed than other parts; has silent or unexpressed genes

Chromatin

DNA-protein complex — DNA is wrapped around proteins to be more compact

Gene

a length of DNA that codes for specific proteins

Nucleosome

a segment of DNA wrapped around 8 histone proteins (2 copies of H2A, H2B, H3, H4) in an unbounded region of the nucleus

Functions of the nucleus

storage and maintenance of cells genetic info, control of gene expression, regulation of protein synthesis machinery

Transcription factors

DNA binding proteins that regulate gene expression

Euchromatin

less condensed areas of chromatin, usually with the cells expressed genes

Nucleolus function

sire of ribosomal RNA synthesis, rRNA processing, and assembly of ribosomal subunits

Ribosomes

made of rRNA and protein complexes which carry out protein synthesis

Bound ribosomes

found in the RER, proteins are either inserted into membranes or organelles or made to be secreted

Free ribosomes

the ribosomes are found in the cytoplasm; proteins function in the cytoplasm