The Nucleus

Nucleus

the command center go the cell.

nuclear envelope

a selectively permeable barrier between the nuclear and cytoplasmic compartments

How many membranes for nucles

two concentric membra

perinuclear space

nuclear laminate 

the proteins in the inner nuclear membrane 

lamina 

part of of nuclear lamina and are intermediate filament proteins and bind to membrane proteins and a

nuclear pore complexs 

where the inner and outer nuclear membranes meet

nucleoporins 

nuclear pore has 8 fold symmetry around the lumen 

lumen

space between me brains

How do things move in and out of nucleas?

ions and small solutes can move through simple diffusion but nucleoprins regulate the movement of macro molecules between nucleus and cytoplasm.

 what is Shipping in and out of nucleus

ribsomal subunits and other RNAs associated with proteins are shipped out and chromatin proteins ribosomal proteins, transcription factor and enzymes are shipped in

How do you know which specific proteins are recognized and moved to where?

proteins of complexes destined for the cytoplasm have specific nuclear export sequences and to be imported have nuclear localized sequences. 

Importins

are transfer proteins that bind to proteins that are to be imported which interact with proteins of pore competes for transfer across the nuclear envlope

what type of energy doe Importins use?

GTP wutg specific GTases help provide direction the transfer/

Chromatin

Dna and all associated proteins involved in the organization and function of DNA. (we have 46 23 pairs)

Chromatids

half of the chromosome held together by complex of cohesion protein 

Histones

Euchromation and Hetrerochromatin dominate in what?

Erochromatin prevails in active cells with large nerurons while herterchromatin is better in cells with little synthetic activity (do not produce a lot of things) like circulating lymphocytes

Barr Body

a type of facultative hetrorchromtin. one of the female X chromosome one of the X gets turned off and transcriptionally inactive

Chromsomal territories

chromsomes have places they stay with the ones with less genes right next to the nuclear envelope and ones with a lot deeper.

homologous

pairs of chromosome they contain allele of the same gene

diploid 

most tissues (stomatiic) cells  2n 

Haploid

have half the number of chromosomes each pairs supraded during meiosis. 

karyotype

a pic of the complete set of chromosomes in a cell, organized and displayed in a systematic way. It shows the number, size, shape, and banding pattern of all the chromosomes in an organism.

nucleolus

nonmembers compact and highly basophilic subdomeination of nuclei of cells actively in protein synthesis.  Have lots of ribsomal RNA undergoing transcription to become ribsomal subunits. 

What happens to uncle in cells requiring intense ribosome production for growth or secretion. 

there will be cromomal regions with genes for rRNA organize to for one or more nucleoli.

what happens to the ribosome sub units created

rRNA are processed in the nucleolus and associate with the ribsomal proteins imported from the cytoplasm via nuclear pores and the small and large subunits export back to they cytoplasm via nuclear pores

mitosis

cell division 

G1

gap between mitosis and the begining of DNA replication . the longest uses active RNA and protein synthesis. Cell volume is halved in mitosis but in G1 becomes normal sized

S

the period of DNA synthesis. DNA replication, histone synthesis, and the beginning of centrosome duplication.

G2

the gap bewtwwn DNA rep and the next mitosis. proteins required for mitosis accumulate. 

G0

cells be temporary or purulently suspended as the new post mitotic cells sepslize and diffrinciate.

mitogen/growht factors

bind to cell surface receptors and trigger a cascade of kinase signaling in cells and begins cycling in postmitotic Go b/c of signals from the extracellular environment

cyclins

regulates cycling overall 

cyclin dependant kinases

cyclins activate this then phoshoryalate specific proteins including enzymes, transcriptions factors for specific sets of gens, and cytosckel subunit s trigger activity that start next past of cycle.

Reasons for cell cycle to stop

inadequate nutrition. innoproriate cellular microenviorment, or DNA damage. Nuclear DNA is monitored very closely 

G1 restriction point 

nuclear damage will be caught here and can repair damage before S phase/  if not safe apoptosis will happen. 

Key tumor supersor

p35

mitosis

only cell cycle phase can bee seen by LM. Parent cell divides and each daughter cell is identical. 

interphase

tine between mitosis G1G2 and S phase

Prohase

the nucleolus disappears and replicated chromatin condenses into sister chromatids joined at the centromere. The two centrosomes with their duplicated centrioles separate to onsite sides od the cell and organize ithe microtubules of the mitotic spindle.. Last llamas and inner nuclear membrane are phosphorylated. causing nuclear laminate and nuclear pore complexes to dissemble and go to cytoplasmic membrane vesicals.  

metaphases 

chromosomes condense further and large protein complex called kintochres attach to mitotic to MS. They line up in middle.

Anaphases

sister chromatics separate and move tords the ends of cell by combination of microtible motor proteins and changes in length of microtubules as the spindle poles move further apart.

Telophase

The two sets of chromosomes are at spindle plates and start uncondensing. microtubules of spindle depolarize and nuclear envelope reusables, a belt like ring of actin filaments associated with myosin develops int the cutoplans of cells idle.

Cytokinesis

end if telophase the ring produces a cleavage furrow that divides the cytoplasm into 2 cells.

which cells cannot do mitosis

nerve and cardiac muscle

stem cells

one daughter stay as stem but others become diffrenicated

progenitor cells 

are cells that are partially specialized and have the ability to divide and produce more cells of a specific lineage.???

What kind of cells don’t have lost of STEM

stable cell pop

meiosis

splitting proces for sex cells/

gametes

the sex cells

synapsis

dan breaks and crosses over

haploid

only one chromosome

apoptosis

programed cell death

apoptotic bodies

small rebrand enclosed which undergo phagocytosis by reboring cells.

neurosis

cell death not by apoptosis eteach of cellular components triggers inflammatory reactions and immigration oof leukocytes ( a potential hazardous tissue response)

Bcl-2 family

family of cytoplasmic protiens that initiates apoptosis, regulate the realize of subside promtiing factors from mitconddria.