Cell Injury and Death Flashcards
Injurious Stimulus results in what 3 things
membrane damage
protein damage
DNA damage
What does increased ROS lead to
damage to lipid, protein, DNA
what does entry of Ca++ lead to
increased mitochondrial permeability
activation of multiple cellular enzymes
What does plasma membrane damage lead to
loss of cellular components
what does lysosomal membrane damage lead to
enzymatic digestion of cellular components
what does protein misfolding, DNA damage lead to
activation of pro-apoptotic proteins
What are the 5 major biochemical mechanisms of cell injury
influx of Ca++, loss of Ca++ homeostatis Mitochondrial damage depletion of ATP accumulation of free radicals defects in membrane permeability
What enzymes does entry of Ca++ activate
prospholipase
Protease
Endonuclease
ATPase
what does phosopholipase do
decrease phospolipids, cause membrane damage
what does protease do
disrupt membrane and cytoskeletal proteins, causes membrane damage
Mos things that cause cell injury will cause injury to what
mitochondria
What do phosphlolipase A2 and sphingomyelin pathways do
break down lipids
free up fatty acids and ceramide
what is the depletion of ATP often caused by
chemical injury or hypoxia
What does decreasing ATP do
decrease Na+ pump
increase anaerobic glycosis
detach ribosomes
What does decreasing Na+ pump do
increase influx of Ca+, H2O and Na+
increase efflux of K+
What does increase influx of Ca+, H2O and Na+
increase efflux of K+ do
ER, cellular swelling
loss of microvilli
blebs
What does increased anaerobic glycolysis cause
decrease glycogen
increase lactic acid
decrease pH
What does decreased pH cause
clumping of nuclear chromatin
What does detachment of ribosomes cause
decreased protein synthesis
oxidative stress
accumulation of samage caused by free radicals
how do free radicals cause damage
form bonds quickly and non-specifically, alter structure of proteins, nucleic acids, and lipids
lipid peroxidation of membranes
double bonds of unsaturated fatty assholes are attacked, forming peroxides. Peroxides form more peroxides
examples of antioxidants
vitamin E, C, A and beta carotene
oxidation of proteins
oxidation of side changes forming disulfide bonds which leads to cross linking
DNA damage
makes single-started breaks which can cause cancer
defects in membrane permeability
caused activation of phospholipases
