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16 Cards in this Set
- Front
- Back
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What happens in interphase?
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cell grow in size. DNA replicated. nucleus exists with decondensed chromosomes. centrosome is duplicated.
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Centrosome is?
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MTOC
9 sets of triplets of alphabeta-tubulins. it also has gamma tubulin rings which are MT nucleating sites. |
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What happens in prophase?
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chromosomes start to condense. centromeres become visible.
centrosomes are separating. |
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What happens in prometaphase?
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Nuclear envelop starts to break because M-CDK has P'ed nuclear lamins.
Chromosomes attach to spindle microtubules at kinetochores. |
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Difference between centromere + kinetochores?
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Centromere is the whole region.
Kinetochores = group of proteins at centromere where spindle microtubules attach. |
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Name 3 different microtubules coming out from the centrosome.
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1. kinetochore Mt. connect pole to kinetochores
2. polar Mt. connect the two poles 3. astral Mt. connect pole to plasma memb. |
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What happens in metaphase?
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chromosomes are aligned at the metaphase plate due to the microtubule-based forces.
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What happens in anaphase?
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Sudden separation of paired chromatids.
Anaphase A: shortening of kMt. chromatids get closer to the pole. forces generated by kinetochores Anaphase B: poles are pushed further apart by 1. sliding force at polar mt's 2. pulling force towards p.memb. |
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What happens in telophase?
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Daughter chromsomes arrive at the poles.
nuclear envelope starts to reassemble. (due to deP of nuclear lamins) |
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Actions of APC?
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APC = anaphase promoting complex. removes inhibitory prot of proteolytic enzyme which cleaves cohesins.
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Cytokinesis:
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contractile ring made up of actin and myosin. ring of actin associated with myosin.
1. contractile ring cleaves cytoplasm 2. starts at the end of anaphase 3. marks the end of M phase |
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How can you do karyotyping from amniocentesis?
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because the tissue is growing fast, use cytoclasin to disrupt spindles. so that way chromosomes are condensed.
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Down syndrome has what genetic defect?
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has 3 of chromsome 21. trisomy 21. failure of chromsomes to segregate properly.
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How does apoptosis happen?
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nucleus fragments. cell membrane blebbing w/o loss of contents, forming apoptotic bodies which are later phagocytosed. no inflammatory response.
mitochondrial enz can be involved. |
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Necrosis is?
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when cell membrane ruptures and lysosomal content enters extracellular space and cause an inflammatory response.
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How is bipolar mitotic spindle formed?
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usually mt free plus ends are "dynamically unstable". however when they are at overlap zone, mt-associated proteins cross-link the mts, stabilizing the plus ends.
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