Chapter 3 Flashcards
cell death caused by attack or injury
necrosis
what surrounds the nuclear pore
glycoproteins
what are the nuclear export signals that transport macromolecules from the ___ into the___
exportins, nucleus, cytoplasm
nuclear pores permit communication between ___ and ___
cytoplasm and nucleus
what 3 things does the nuclear lamina help do
- organize/support lipid bilayer membrane 2. organize/support perinuclear chromatin 3. assemble vesicles to re-form the nuclear envelope following cell division
____ degrade regulatory and structural proteins in the nucleus and in the cytoplasm
caspases
what family of GTP-binding proteins regulate exporting and importing transport
ran
after the cell ruptures during necrosis, cell contents are exposed to neighboring cells which initiates a ____
inflammatory response
what are the non-membranous structures that are embedded in the rim of the nuclear pore
glycoproteins
the nuclear matrix contains 10% ___, 30% ___, 1-3% ____, and 2-5% ___
protein, RNA, DNA, nuclear phosphate
what is the nuclear envelope composed of
inner and outer nuclear membranes
how many nucleoli are there typically per cell
no more than 2 or 3
In malignant cells, the nucleolus may become ___
hypertrophic
is the small amount of DNA in the nucleolus active or inactive
inactive
when is activation of caspases induced
when certain cytokines, such as tumor necrosis factor (TNF), released by signaling cells, binds to the TNF receptor of the target cell
The cell’s ribosomal subunits are organized and assembled within the ____, except those located in the ___.
nucleolus, mitochondria
what is the largest organelle of the cell
nucleus
the nucleolus is involved in what syntehsis
rRNA
what membrane faces the cytoplasm and is continuous with the RER; it is also studded with ribosomes on its cytoplasmic surface
outer nuclear
what is the nucleus surrounded by
nuclear envelope
what is the deeply staining dense non-membrane bounded structure within the nucleus
nucleolus
the nucleolus stains basophilic with ____ and ___
hematoxylin and eosin
what type of cell has extruded nuclei
red blood cells
what is the center for ribosomal RNA
nucleolus
what four things does the nucleoplasm consist of
interchromatxn and perichromatin granules, RNPs, and the nuclear matrix
what are the 4 distinct areas of the nucleolus
fibrillar center, pars fibrosa, pars granulosa, nucleolar matrix
where are snRNPS location
most in the nucleus, some in the nucleoli
what is an example of a cell that possesses several nuclei
osteoclasts
proteins that carry nucleocytoplasmic shuttling signals interact with ___
mRNA
what separates the inner and outer nuclear membranes
perinuclear cistern
TNF receptors are ____ proteins
transmembrane
what mediates bidirectional traffic between the nucleus and cytoplasm
group of target proteins
what area of the nucleolus is a network of fibers active in the nucleolar organization
nucleolar matrix
apoptosis is regulated by highly conserved genes that code for which family of enzymes
caspases
what two things is the inner nuclear membrane is in close contact with
nucleoplasm and nuclear lamina
the interchromatin granules contain ___ and ___, what is their function
RNPs and several enzymes, function is unclear
the nucleus possesses a _____ that is continuous with the ____ of the cytoplasm and the nuclear envelope.
This reticulum houses nuclear ____ that functions within the nucleus.
nucleoplasmic reticulum , endoplasmic reticulum, calcium
what makes up the nuclear pore complex
nuclear pore, associated glycoproteins, cytoplasmic fibers, a transporter, nuclear basket
what are the nuclear localization signals that transport cargo (protein subunits of ribosomes) from the ___ into the ___
importins, cytoplasm, nucleus
what is the genetic material of the cell
chromatin
what is the term for cells driven into the genetically determined process of dying
programmed cell death (apoptosis)
what are the 3 major components of the nucleus
chromatin, nucleolus, nucleoplasm
what area of the nucleolus that assembles maturing ribosomal subunits
pars granulosa
what does the group of target proteins contain
nuclear localization signals, nuclear export signals
the nuclear pore functions in ___ ____ ___
bidirectional nucleocytoplasmic transport
what are the structural components of the nuclear matrix
nuclear pore-nuclear lamina complex, residual nucleoli, residual RNP networks, fibrillar elements
what contains macromolecules and nuclear particles involved in the maintenance of the cell
nucleoplasm
Cells die as a result of what 5 factors
acute injury, accidents, lack of vascular supply, destruction by pathogens or the immune system, genetic programming
how are large particles transported through the nuclear pore complex
must have a receptor to bind to
Functionally, the nuclear matrix is associated with: ____ sites, ___ and ___ transcription and processing, ____ receptor binding, ____ proteins, ____ binding, ____ viruses, and ___ proteins
DNA replication sites, rRNA and mRNA transcription and processing, Steroid receptor binding, Heat shock proteins, Carcinogen binding, DNA viruses, Viral proteins
snRNPs (small nuclear ribonucleic particles) participate in ___, ___, and ____ hnRNPs.
splicing, cleaving, transporting
what additional functions does the nucleolus perform (6)
regulate cytokinesis, Inactivating mitotic cyclin dependent kinases, modifying small RNAs that moderate and modify pre-rRNA, assemble RNP, engage in nuclear export, play a role in aging
what is the pale staining center containing inactive DNA (not being transcribed
fibrillar center
the nuclear side of the enveloped is lined by what; it is a network of intermediate filaments that maintain the shape of the nucleus
nuclear lamina
what membrane faces the nuclear contents
inner nuclear
what area of the nucleolus contains nucleolar RNAs being transcribed
pars fibrosa
what is formed when the nuclear envelope is perforated at various intervals
nuclear pores
The size, shape, and form of the nucleus are generally constant for a particular cell type, a fact useful in clinical diagnoses of the degree of ____ of certain ___ cells
malignancy of certain cancerous cells.
