Cell Biology Flashcards
(19 cards)
Nuclear envelope
Lipid bilayer with an inner membrane and an outer membrane
Separates cytoplasm from the nucleus
Nucleolus
No membrane
Site of rRNA transcription, rRNA processing, and ribosomal assembly
Dense tubular component, granular component, and fibrillar center
Chromatin
DNA wrapped around histones to form nucleosomes
2 types: active and inactive
Euchromatin
Transcriptionally active chromatin
Heterochromatin
Transcriptionally inactive chromatin
Nuclear organizational region (NOR)
Short tandem repeats of rRNA
Code for the production of rRNA
Rough endoplasmic reticulum (RER)
Ribosomes embedded into the membrane
Captures select protein from the cytosol
Components of the nucleolus
Dense tubular component
Granular component
Fibrillar component
Dense tubular component
Nascent rRNA
Granular component
Site of assembly of pre-ribosomal subunits
Fibrillar center
rRNA genes
RNA polymerase
Signal recognition particles (SRP)
Entry to nuclear pores
Size-regulated entry
Mutations in lamin-associated proteins
A type of muscular dystrophy
Pelger-Huet anomaly
Import signal
T-antigen
Importin proteins
Recognize the nuclear localization sequence
Alpha
Beta
RAN binding to GTP
Dissociation of the protein from the importin
Exportin complex
Nuclear export sequence (NES) needed
Requires GTP
Heat shock protein (hsp90)
Prevents binding of steroid hormone to carrier proteins
Pelger-Huet Anomaly
Autosomal dominant mutation
Nuclear lamin B receptor protein that anchors the nuclear membrane to lamins
Incomplete differentiation of WBC
Benign, but could mimic cancer
