RAD BIO EXAM 2!

LD50

dose at which half of radiation individuals will die if they recieve treatment

direction ionization

alpha, beta, and proton, collide with electon

indirect ionization

neutrons, deeply penetrate

direct action

radiation interacts with a molecule

indirect action

produces free radicals

free radical

free atom that has unpaired electron

photons produce

spurs

particles produce

blobs

degradation

breaking large molecule into smaller units

chromosome abarrations

occur before DNA replication

chromatid abberations

occur after DNA replication

at low doses there are _________ “hits”, so one hit causes a ________ strand break

fewer, double

at high does there are __________ “hits”

more

cell death at high doses is due to?

an accumulated effect of hits

what are the three types of DNA damage?

lethal, potentially lethal, and sublethal

lethal

irreversible and irrepairable

lethal damage result from ___________ ___________ that results in abarretion

improper repair

potentially lethal

is lethal unless reapaired

sublethal

repairable injury

nucleotide excision repair

removes thymine dimers

base excision repair

removes chemically altered bases

mismatched repair

corrects mis-paired bases

homologus recombination repair

repair double stranded breaks, need sister chromatids, late S or G2

non-homologus end joining

repair double stranded breaks, proteins bind to ends, G1

cyclin dependent kinases

regulate the progression through the cell cycle

kinases

regulate activity by phosphorylating proteins

cyclins

proteins that activate cells

pausing the cell cycle allows for DNA damage to be __________

repaired

necrosis

unplanned cell death

apoptosis

controlled cell suicide

apoptosis is caused by

DNA damage, hypoxia, activation of death receptors

oncogenes

genes that promote cancer

proto-onco genes

genes that can become oncogenes via mutation

tumor suppressor genes

prevent cancerous growth