Cambridge Chat (previously New Cambridge Students Entry 2004)

crana9

im still not convinced. how exactly would the lysosomes kill off the cell? they are well small compared to the cell, and if they all just released their contents, it wouldnt do anything because theyre only active in acid conditions.

It seems to mainly involve caspase protein cascades and not a mention of lysosomes.

Well I think my biology teacher mentioned something about some lysosomes containing inactive lytic enzymes which when exposed to the cytoplasm get are activated and kill the cell. It was a long time ago, and I was rather drunk at the time so feel free to ignore me.

Reply 9383

polthegael

My understanding (and I may well be wrong) was that signal molecules either from neighbouring cells or intracellularly come along and start a cascade reaction which would result in the membrane around the lysosome degrading and releasing the proteases, lipases and all the other nasties from the lysosome which degrade the cell. The problem I always had with that is, after nucleases degrade the genetic information the cell can do nothing to stop the runaway effects of the enzymes. This should destroy other cells once they get released into the tissue fluid. Maybe I'll ask KT when Eastenders is over! :smile:

well, as i just said, the lysosome nasties are only active in conditions of ~pH 5 which the cytosol is not.

I found this:

At one time, it was thought that lysosomes were responsible for killing cells scheduled to be removed from a tissue; for example, the resorption of its tail as the tadpole metamorphoses into a frog. This is incorrect. These examples of programmed cell death (PCD) or apoptosis take place by an entirely different mechanism. Link to a discussion of apoptosis.

from
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/Lysosomes.html

hence i conclude this was yet another A-Level Lie

i may assemble a collection of these and post them to my teacher. or not, of course.

Reply 9384

KHL

polthegael

My understanding (and I may well be wrong) was that signal molecules either from neighbouring cells or intracellularly come along and start a cascade reaction which would result in the membrane around the lysosome degrading and releasing the proteases, lipases and all the other nasties from the lysosome which degrade the cell. The problem I always had with that is, after nucleases degrade the genetic information the cell can do nothing to stop the runaway effects of the enzymes. This should destroy other cells once they get released into the tissue fluid. Maybe I'll ask KT when Eastenders is over! :smile:

http://www.ucalgary.ca/UofC/eduweb/virtualembryo/death_intro.html

you'll be getting quite a bit about apoptosis next year as part of IB medic/bionatsci pathology.

and btw, it was originally coined as apo-ptosis, so it's pronounced a-po-to-sis. (2nd p is silent. though everyone nowadays seems to pronounce it other than poor old prof wyllie, who, incidentally, coined that term.)

and the beauty of proteases and other lytic enzymes are that they are catalysts, i.e. not consumed in reactions, so relatively small amounts of these nasties are more than able to digest large chunks of the cell if released from lysosomes.

Reply 9385

Katie J

10

androidkiller

Dammit. Medics get such better practicals.

Hello

(it really annoys me now that there are certain people I would have met with or without this website, not sure why it should annoy me but it does!)

Our practicals are all voluntary, I think the arch & anth staff are scared if they even mention science everyone will run away!! :mad:

I did an erg thing today, apparently I'm not rubbish afterall despite not having any coordination! My foot hurts even more though and now it's going sort of blue underneath, stupid foot, I haven't done anything to it!! :confused:

Reply 9386

priya

14

Katie J

Hello

(it really annoys me now that there are certain people I would have met with or without this website, not sure why it should annoy me but it does!)

Our practicals are all voluntary, I think the arch & anth staff are scared if they even mention science everyone will run away!! :mad:

I did an erg thing today, apparently I'm not rubbish afterall despite not having any coordination! My foot hurts even more though and now it's going sort of blue underneath, stupid foot, I haven't done anything to it!! :confused:

argh i have to go on the ergs for about 30 mins at some point between now and tuesday...rowing at 7am on tuesday, fun fun fun

Reply 9387

Katie J

10

priya

argh i have to go on the ergs for about 30 mins at some point between now and tuesday...rowing at 7am on tuesday, fun fun fun

Went today at 6:30am and tomorrow at 6:30am!! :eek:

I didn't know what I was letting myself in for when I signed up, I thought novicing was just nice little splashing abouts in boats on Sunday afternoons! I wasn't expecting to have to do anything training wise or stretching other than the basic teaching!! I also wasn't expecting my right foot to randomly rebel against me!!

Reply 9388

priya

14

Katie J

Went today at 6:30am and tomorrow at 6:30am!! :eek:

I didn't know what I was letting myself in for when I signed up, I thought novicing was just nice little splashing abouts in boats on Sunday afternoons! I wasn't expecting to have to do anything training wise or stretching other than the basic teaching!! I also wasn't expecting my right foot to randomly rebel against me!!

my plan is to row for a term, buy the ssbc hoodie, and then wear it for the next 3 years. but possibly discontinue rowing if it all gets too much. most of the people in my college have done this lol

Reply 9389

has anyone else noticed this trend for everyone to be wearing "leavers hoodies" from their school? i find it all quite odd

Reply 9390

Katie J

10

crana9

has anyone else noticed this trend for everyone to be wearing "leavers hoodies" from their school? i find it all quite odd

We didn't get leavers' hoodies :frown:

Piyra, I have a friend only in the rowing scene for the scary lycra suits!! She's a little strange...

Reply 9391

crana9

has anyone else noticed this trend for everyone to be wearing "leavers hoodies" from their school? i find it all quite odd

I get a leaver's tie from mine :wink:

. And £500 apparently.

Reply 9392

even had we had the option to have one i dont think i would have fone

Reply 9393

crana9

even had we had the option to have one i dont think i would have fone

Excuse me?

Reply 9394

visesh

Excuse me?

done. not fone.
with regards to hoodies

Reply 9395

crana9

done. not fone.
with regards to hoodies

Ahhh thanks.

If anyone sees someone with a Black NHS(or maybe Nottingham High School) Cross country hoodie, say hi to him from me :smile:

. Medic at Catz.

Reply 9396

Camford

12

Damn it!! I need bread and ham!! They are running out on me!! Sainsbury's I'm coming to get you!!!

Reply 9397

Camford

Damn it!! I need bread and ham!! They are running out on me!! Sainsbury's I'm coming to get you!!!

Go then. Leave us alone. :wink:

Reply 9398