The Nucleus Flashcards
Macroagregado de histonas y las 46 moléculas forman
Cromosomas
Sustancia que compone al núcleo
Cromatina
La cromatina mas teñida , la más condensada se llama
Heterocromtina
La cromatina menos condensada y menor afinidad por colorantes se llama
Eucromatina
Núcleos pequeños muy bien coloreados se dice que son
Núcleos picnoticos
Producción de células somáticas se llama
Mitosis
Muerte celular programada
Apoptosis
Momento central del ciclo celular , donde se sintetiza ADN
Fase s
Las 46 moléculas de ADN están asociadas a proteínas ácidas llamadas
Histonas
Mass of DNA and associated proteins
Chromatin
A selectively permeable barrier between the nuclear and cytoplasmatic compartments
Nuclear envelope
Narrow that separates nuclear envelope call perinuclear space is from
30 nm - 50 nm
Highly organized meshwork of proteins called the
Nuclear lamina
Inner and outer nuclear membranes are bridged at
Nuclear pore complex
Core proteins of a nuclear pore complex called … That are displayed eightfold symmetry around the lumen
Nucleoporins
Numbers of channels of a growing cell for pass macromolecules in the nuclear envelope
3000-4000 passing 1000 macromolecules per second
Macromolecules shipped out of the nucleus incluyed
Ribosomal subunits and other ARN associated with proteins
Inbound traffic consist of
chromatin molecules, ribosomal proteins, transcriptional factors and enzymes
Energy for the transport is derived from
GTP
Sex chromatin that is one of the two X chromosomes present in females
Barr body
DNA in chromatin is extensively packaged by associating basic proteins called
Histones
The structural unit of DNA and his histones is the
Nucleosome
Has two copies of eight small histones that are
H2A, H2B,H3,H4
The larger histone associated with ADN and surface of the core
H1
Each long DNA double helix with its associated proteins is a
Chromatid
After DNA replication two chromatids held together by complexes of cohesin proteins Make up each
Chromosome
The member of each chromosomal pair are called
Homologous
Forms of the a gene
Alleles
Somatic cells are considered, be cause they contain pair of chromosomes
Diploid
Genetics refer to diploid cells as
2n
Number of chromosomes in human
23
Half of numbers of chromosomes separated in meiosis
Haploid like sperm cells or germ cells
Microscopic analyzed chromosomes arrested in mitotic metaphase by … That disrupted microtubules
Colchicine
Principal funtion is Make proteins, have An intense basophilia because his concentration rRNA that is transcribed, processed and complexed into ribosomal subunits
Nucleous
Damage to DNA of proto-oncogenes and failure of the cells to be eliminated
Neoplastic proliferation
Neoplastic proliferation with slow growth and no invasiveness to neighboring organs
Benign
Cáncer is the common term, with rapid growth and invade other organs
Malignant
Bound to the inner membrane of the nuclear envelope is the
Nuclear lamina
Contain more than 30 core proteins (nucleoporins)
Nuclear pore complexes
The regular sequence of events that result in new cells is termes the
Cell cycle
Phases of the cell cycle
Mitosis,G1,S,G2
The time gap between mitosis and ADN replication
G1
Period of DNA synthesis and centrosome duplication
S
Gap between DNA replication and next mitosis , and proteins accumulate
G2
The longest and most variable phase of cell cycle , and is a period of active RNA and protein synthesis, the cell volume reduce by half during mitosis
G1
Temporarily or permanently suspended
G0
Cylcing is activated in posmitotic G0 cells by proteins signal from the extracellular enviroment call
Mitogens or growth factors
Cycle y is regulated by a family of proteins called
Cyclins
Cyclins activate
Cycle dependent kinases
Medida de la doble hélice del ADN
2nm
Messure of ADN with histones filaments of nucleosomes connected by ADN
11nm
Messure of nucleosomes packed in chromatin fiber
30 nm
Mesure For transcription form loops tethered to protein scaffold
300 nm
Is a type of cáncer occurring in the eyes cause by Rb a gene coding for a key protein active at the G1 restriction point that blocks cell cycle
Retinoblastoma
Entire chromosome at metaphase messure
1400 nm
Condensed heterocromatin and dispersed euchromatin messure
700nm
Genes coding for proteins important in the control of cell proliferation and differentiation called
Proto- oncogenes
Changes in a protooncogenes structure
Oncogenes
At the centromere region of each chromosome a large protein complex serves as a site for attachment to microtubules
Kinetochore
Time spend in G1
25 hours
Time spend in S phase
8 hours
Time spend on G2 phase
2.5-3 hours
The time of the whole cell cycle
24 to 36 hours
Time spend in prophase
+- 1 hour
Metaphase normally last
Anaphase last only
Telophase last only
Minutes
The three important checkpoints control are
Start G1/S , metaphase/ anaphase, G2/M
His Cycling serves to renew the differentiated cells of tissue as needed
Stem cells
Early in the process the homologous chromosomes of each pair come together in An activity termed
Synapsis
During synapsis double stranded breaks and re pair DNA some of which result in reciprocal DNA exchanges called….. Between the aligned maternal and paternal chromosomes
Crossovers
In humans spermatogenesis prophase I normally last….
3 weeks
Oocytes arrest in the meiotic phase from their formation in the fetal ovary through the womans reproductive maturity that is about
12 years to nearly five decades
Mitosis is a cell división that produces
Two diploid cells
Meiosis produce
Four haploid cells
Apoptosis is controlled by a cytoplasmic proteins in the
Bcl 2 family
Loss of mitocondrial function and are activated some enzymes called
Caspases
Los indicios microscopicos de la apoptosis se llaman
Cuerpos apoptoticos
El concepto de muerte celular opuesto a la apoptosis se llama
Necrosis
