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82 Cards in this Set
- Front
- Back
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M phase
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division: mitosis
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G1 phase
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-prep phase btwn mitosis/dna replication
-checks for DNA damage |
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S phase
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-genome replicated
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G2 phase
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-prep phase for mitosis, checks for completion of DNA replication
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GO phase
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-quiescent, not actively dividing
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G1 restriction point
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-montiors cell size, envmt conditions, interactions with neighbors
-commits to divide |
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G1 checkpoint
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-stops cell cycle DNA damage detected
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S phase checkpoint
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-stops cell cycle DNA damage/stalled replication forks
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G2/M checkpoint
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-stops cell cycle unreplicated DNA/DNA damage
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metaphase spindle assembly checkpoint
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-delay separation of daughter chromatids until attched to mitotic spindle
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CDKs
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cyclin-dependent kinases
-pro that drives phases of cell cycle/transition |
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positive reg of Cdk
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-phosphorylatins enhance activity
-dephosphorylation at inhib sites -cyclin binding alters conformation and inc activity |
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negative reg of Cdk
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-phosphorylation at inhib sites
-ubiquitin mediated destruction of cyclines |
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DNA Replication
where? when? |
-nucleus
-S-phase |
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euchromatin/heterochromatin
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-euchromatin replicated early
-heterochromatin replicated late |
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Replication steps
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-initiation
-elongation -termination |
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helicase
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-unwinds DNA at origin
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DNA pol alpha
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-primase
-synth RNA primers needed for synthesis |
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single strand DNA binding protein
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stabilizes opening of double helix
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DNA pol S
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-bulk of DNA synth after RNA primers
-formation phosphodiester bonds |
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DNA topoisomerase
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=gyrase
-relieves tension ahead of fork |
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DNA pol S
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-proofreading activity
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DNA ligase
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-joins Okazaki fragments
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Topoisomerase II
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-cuts, reseals newly synth DNA molecules so they can separate
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telomerase
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-use RNA primer to generate special end structures (telomeres)
-functions as reverse transcriptase |
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DNA transcription
where? when? |
-nucleus
-high levels in G1, S, G2 phase -euchromatin genes transcribed |
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core promoter
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-region around transc start site
-includes TATA box (recruits RNA pol) |
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enhancers
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-DNA sequences increase transcription
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silencers
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-DNA seq decrease transcription
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cis-acting sequences
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-enhancers, silencers, TATA box
-bind trans-acting pro |
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RNA Pol I
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-transcribes rRNA genes
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RNA Pol II
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-transcribes mRNA and snRNA
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RNA Pol III
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-transcribes 5S rRNA and all tRNA
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mRNA
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-translated into peptide
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rRNA
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-used in building of ribosomes
-18S = small subunit -28S,5.8S, 5S rRna = large subunit |
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tRNA
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-carry AA to polypeptide
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small nuclear RNA
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-snRNA
-mediates processing of primary transcripts |
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capping
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-add 7-methylguanosine-5'-triphosphate at 5' end
-protects from degredation -regulates RNA export -initiates ribosomal binding |
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polyadenylation
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-add poly-a tail to 3'
-stabilization/nuclear export |
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splicing
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-removal introns by spliceosome
-branch point A catalyzes |
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alternative splicing mRNA
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-different patterns splicing = diff pro from same gene
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genetic code
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-triplet code (codons)
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start codon
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-AUG (methionine)
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stop codon
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-UGA
-UAA -UAG |
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initiation complex
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-tRNA w/methionine
-initiator AUG codon |
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proteasomes
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-in nucleus
-degrade uneeded/damaged pro |
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ubiquitin
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-tag pro for degredation
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DNA binding structural motifs
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-helix-loop-helix, leucine zipper, zinc finger, steroid hormone receptor motif
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DNA methylation
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-inhibits transctiption
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nucleosome remodeling complexes
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-move nucleosomes
-help transc factors find binding sites |
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histone modifications
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-influence chromatin compaction
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histone deacetylase
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-remove acetyl groups
-favors compaction |
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histone acetylase
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-chromatin more accessible
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XIST gene
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-X inactivation
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microRNA
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-block expression of other genes
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antisense RNA
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-binds to mRNA, physically blocks translation
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smal interfering RNA
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-interfere with expression of specific gene
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single-stranded binding proteins
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-bind to separated ssDNA to prevent annealing back together
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transcription termination
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-palindrome
-poly u sequence |
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fibroblast vs. fibrocyte
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-fibroblast: proliferative capable of mitosis
-fibrocyte: fully differentiated, slowed metabolism |
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fibroblast: function?
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-synthesize/secret ALL ECM components
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nonactivated mast cells
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-granules storing histamine, proteases, proteoglycans
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activated mast cells
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-release histamine, proteases, proteoglycans
-synth mediators from arichidonic acid |
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macrophage
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-antigen presenting, phagocytic
-lots of signaling |
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collagen
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-triple stranded
-characteristic, repeating structure |
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reticulin fiber
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-support fo lymphoid tissue/liver
-made of type III collagen -network: fluid/lymph pass through |
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elastic fibers
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-made of proelastin, microfibril-assoc glycoprotein, fibrillin 1/2
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fibrillin 1
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-force-bearing structural suport
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fibrillin 2
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-regulates assembly
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elastic fibers
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-add resiliency to connective tissue
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glycoaminoglycans
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-polysach. side chains of proteoglycans
-polysach. of linear repeat disach. units |
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proteoglycans
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-any pro w/one + covalently attached glycosaminoglycan chains
-very hydrated |
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proteoglycan: structure?
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-axial hyaluronan molecule
-pro attatched by linker pro -glycosaminoglycans attch to core pro |
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fibronectin
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-binds integrins, collagen, proteoglycans
-helps cells attach to ECM |
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laminin
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-bind collagen fibers via pelecan and entactin, and cell integrins
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dense regular connective tissue: location? structure?
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-in tendons and ligaments
-reg. oriented parallel bundles collagen |
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dense irregular connective tissue: location? structure?
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-dermis of skin, submucose digestive tube
-fibroblasts sparse |
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loose connective tissue
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-abundant e fibers and collagen bundles
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proto-oncogene
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-normal form of oncogene
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oncogene
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-cell affected by CA
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characteristics of CA cells
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-reduce dep. on signal from other cells
-less prone to apoptosis -proliferate indefinitely -unstable w/high mutation rate -invasive, lack adhesion -survive/proliferate foreign tissues |
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accumulation of mutations
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-why CA is old age disease often
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