Cell Bio Block 3

shanachka's version from 2015-11-28 20:58


Question Answer
Euchromatin is transcriptionally
Heterochromatin is transcriptionally _________.inactive
Promoters are _________-rich regions located 5' upstream of transcription start site of all genes.A-T
Rifampicin blocks _________, an important enzyme needed for prokaryotic transcription.RNA polymerase
CYP2D6 is important for metabolism of about 25% drugs in clinical use. If there was a promoter mutation, what would that result in?increased expression = increased metabolism = potential drug overdose
What are the 3 transcription factors for the human globin gene?BCL11A, GATA-1, KLF1
Which transcription factor for the human globin gene is the main Hb switching factor needed to suppress expression of fetal gamma globin?BCL11A
Epigeneticsphenotypic changes that don't result from changes in nucleotide sequence but rather from chromatin modifications
Differentiate between totipotent/omnipotent, pluripotent, multipotent, unipotent/oligopotent stem cells.totipotent/omnipotent can differentiate into an entire organism; pluripotent can differentiate into most cells; multipotent can differentiate into few cells; unipotent/oligopotent can differentiate into 1-2 cells
Where are embryonic stem cells isolated from?early blastocyst
Embryonic stem cells are: totipotent, pluripotent, multipotent, unipotentpluripotent
Which 2 transcription factors suppress gene expression of embryonic stem cells and help them remain in an undifferentiated state?Sox2, Oct4
Adult stem cells are: totipotent, pluripotent, multipotent, unipotentmultipotent or unipotent
Where are telomeres located?at ends of chromosomes
Are telomeres replicated? What happens to their length after each cell division? What is the significance behind these facts?not replicated; shorten -- they limit the replicative lifespan of cells (role in aging); they don't shorten in cancer cells
Is telomerase expressed in most cells?No
Which cdk's and cyclin's are used in G1 phase of cell cycle?cdk's 2, 4, 6; cyclin's D, E
The active sites in cdk's of G1 phase of cell cycle are:Thr14, Tyr15
Activation/Inhibition of Thr14 and Tyr15phosphorylated (inactivated) by Wee1 kinase and dephosphorylated (activated) by Cdc 25 phosphatase
Activated (_________) cdk's of G1 phase of cell cycle activate _________, a tumor suppressor, via _________.dephosphorylated; pRB; phosphorylation
pRB binds to transcription factor _________ to prevent cell from entering _________ phase.E2F; S
p21, whose production is stimulated by _________, inhibits _________.p53; cdk2
_________ inhibits cdk's 4 and 6.p16
Which common sexually transmitted virus inhibits tumor suppressors?HPV
HPV causes _________ protein to bind to p53 and _________ protein to bind to pRB.E6; E7
Which cdk and cyclin are used in S phase of cell cycle?cdk2; cyclin A
Which cdk and cyclin are used in M phase of cell cycle?cdk1; cyclin B
Sensor ATM (Ataxia Telangiectasia Mutated) binds to DNA _________ strand breaks.double
Sensor ATR (AT and Rad 3) binds to DNA _________ strand breaks.single
Hyperplasiareversible increase in cell number
Dysplasiareversible alteration in cell size, shape, or organization (precancerous)
Neoplasiaabnormal new growth (malignant or benign)
Carcinogenesis requires an _________ carcinogen (i.e. mutagen).initiator
Some examples of promoters of carcinogenesis are:estrogen, progesterone, smoking, drinking
Proto-oncogenesnormal genes regulating cell growth
Oncogenesmutated proto-oncogenes
Interior of solid tumors have a rich blood supply. -- True or FalseFalse, it lacks blood supply, causing cells of interior to die of necrosis
During invasion and metastasis of cancer, the cancer cell stops expression of _________ to reduce cell-cell adhesion and increase migration.E-cadherin
Angiogenesisprocess by which new blood vessels form from existing vessels
_________ stimulates angiogenesis.VEGF

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