Toxicology Lecture 5

Cellular and Toxicity Targets

What 3 ways do the toxins like to fuck up cells?

1. use up all the ATP

2. Making the cell produce too much Ca2+

3. Creating over-reactive oxygen-species?

What does too much Ca2+ do in a cell?

Too much Ca2+ in the cytoskeleton makes it unstable, and if there’s it’s unstable than the cell might KILL ITSELF.

What is the “Downward death spiral“ in a cell?

1. The toxin uses up a whole bunch of ATP, causing Ca2+ to flood into the cytoplasm

2. The cell freaks out and pumps C2+ into the mitochondria, which messes up its H+ concentration.

3. Cell can’t make ATP anymore, free radicals form, and Ca2+ increases.

4. Any ATP left over gets used up trying to deal with the ROS and free radicals.

5. The ROS damage the membranes, causing the cell to leak.

   Death.

What is cell necrosis?

Death!

What is cell apoptosis?

Also called programmed cell death.

What triggers cell death, really?

damage to the mitochondria. The more damage, the more the cell freaks out and goes rogue. If it freaks out to much, an enzyme called the caspase, nicknamed the EXECUTIONER, tells the to the cell to off itself.

What happens if the executioner doesn’t come in time?

The membrane becomes permeable, starts leaking, and yet somehow the cell swells, bursts, and DIES.

What do carcinogens actually do? Like yeah they cause cancer but what do they do that increases cancerness? N&E 4 things.

1. Cell division is a very regulated thing. Some carcinogens say no to that and cause cells to divide uncontrollably. Or fuck with DNA.

2. Fuck with DNA

3. Kill cells really fast. The more cells die, the faster they have to get more cells, which increases the chances of a cell messing up. and you DIE.

4. a toxin that mimics a hormone that tells cells to divide can cause similar problems to above.