Test Block 3 Flashcards
what kind of chromatin is actively dividing
euchromatin
what does PCNA do
help to keep the polymerase bound
proof reading ability of DNA is duect to a _________
3’ to 5’ exonuclease activity
endonuclease occurs at the ________. exoonuclease occurs at the ______
middle; end
Explain the steps of BER
- DNA cleaved by DNA MYH glycosylase
- recognized by AP endonuclease
- PARP binds
- Pol fills and ligase seals
Explain steps of MMR
- MSH proteins detect mismatch
- MLH proteins recruit exonuclease
- pol fills, ligase seals
lynch syndrome is associated with which repair mechanism
MMR
lack of MLH1 leads to degradations of ____, lack of MSH2 leads to loss of ____
PMS2;MSH6 (MMR)
how are thymine dimers repaired
NER
explain steps of NHEJ
- ku70 and ku80 bind to broken ends
- nuclease artemis is recruited
- pol fills, ligase seals
which repair mechanism uses sister chromatid as a template for repair?
homologous recombination repair (BRCA1, BRCA2, PALB). Loss of heterozygosity
what is the order of repair mechanisms by length
BER, MMR, NER, HRR, NHEJ
removes a postitive charge from lysine, making DNA easier to unwind and become transcriptionally active
HAT
how does methyl groups encourage the packaging of DNA
by physically blocking the binding of transcription factors
where does methylation of DNA occur
the 5’ carbon on cysteine
antibodies contain _____ light and _____ heavy chains
two; two
DNA elements that act at a distance to repress transcription
silencers
how do steroid receptors work
HSP bind receptors in cytosol
ligand (cortisol) displaces HSP
GR dimerizes and enters nucleus
what are the stop codons
UGA, UAA, UAG
what is the start codon
AUG
what does eIF3 do
prevents premature binding of ribosomal subunit
what does EF1 do
Blocks the A site
what does EF2 do
attach to charged tRNA
How is EF2 regulated
when phosphorylated, it is inactive
How is EIF4 regulated
insulin binds, phosphorylates to activatew EIF4
what blocks the binding of aminoacyl tRNA by blocking the A site
tetracyclins
what binds to the 30s subunit to prevent intitation
aminoglyside (streptomycin)
what does erythromycin do
blocks 50s subunit
what inhibits peptides transferase
lincomycin and lindamycin
what activates EEF2
Diptheria Toxin
what antibiotics wrecks your teeth
tetracyclin and deoxycyclin
what enzyme catalyzes peptide bond formation
peptidyl transferase
how does tetracyclin prevent bacterial translation
blocks the A site
what was given to Dr. Rees son
clindamycin
to enter G1 cells must have
high concentration of growth factors
sense adhesion
have sufficient nutrients
what does increased cyclin D lead to
increased CDK4 and CDK6, increases CDK1/2 and Cyclins A, B, E
Bad is active when it is _________
nonpohosphorylated (AKT regulates)
what does MAP Kinase activate
AP-1 (jun and fos) and induction of myc and fos
what is guardian of the genome
p53
Familial adenomatous polposis is associated with
APC
Lynch syndrome is associated with which genes
MLH1, MSH2
describe cell proliferation of retinoblastoma
GF, Cyclin D, CDK4/CDK6, phosphorylates RB/E2F complex, E2F breaks away and enters nucleus to begin proliferation
DNA damage triggers an _______ in p53
increase
what does p53 stimulate
transcription of p21