ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: monokekie on March 06, 2010, 06:14:10 pm
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does anyone know whether they excrete wastes, or store wastes?
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Thanks Biology Moderator *thumbs up* :)
um,, i got another Q, j/w, what's the difference between hypotonic and hypertonic?
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Hypotonic - a solution with less solute than solvent
Hypertonic - a solution with more solute than solvent (think someone who is hyper/hyperactive = lots of sugar)
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kekie ... !!!
you do bio? ::)
wow :o
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heh, as you can see, i am just a noob @ bio who has heaps of study to do :)
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is that part of your uni course? a minor or something like that? :P
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i am studying biology @ uni as a subject, :P
Hypotonic - a solution with less solute than solvent
Hypertonic - a solution with more solute than solvent (think someone who is hyper/hyperactive = lots of sugar)
and thanks,Minibox :)
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Hypotonic - a solution with less solute than solvent
Hypertonic - a solution with more solute than solvent (think someone who is hyper/hyperactive = lots of sugar)
can i just add that when your talking about tonicities... its the total concentration of non-penetrating solute particles on the two sides of the membrane... so if the total concentration of non-permeable solutes is 300 mOsmol/l in solution A (eg.extracellular fluid) and the total concentration of non-permeable solutes is 200 mOsmol/l (eg.intracellular fluid) in solution B. Then water will move from solution B to solution A... so cells would shrink and the extracellular solution is hypertonic to the cells.
the opposite occurs in hypotonic extracellular solutions, where there is a higher concentration of non-penetrating particles in the intracellular compartment compared to the outside, so net water movement flows into the cell and it swells.
and if solutions contain penetrating solutes then they have zero tonicity... even if they have different osmolarities (which takes into account the total concentration of all solutes)....
hmm am i confusing...lol here just read wiki
Osmolarity and tonicity are related, but different, concepts. Thus, the terms ending in -osmotic (isosmotic, hyperosmotic, hyposmotic) are not synonymous with the terms ending in -tonic (isotonic, hypertonic, hypotonic). The terms are related in that they both compare the solute concentrations of two solutions separated by a membrane. The terms are different because osmolarity takes into account the total concentration of penetrating solutes and non-penetrating solutes, whereas tonicity takes into account the total concentration of only non-penetrating solutes.[1]
Penetrating solutes can diffuse through the cell membrane, causing momentary changes in cell volume as the solutes "pull" water molecules with them. Non-penetrating solutes cannot cross the cell membrane, and therefore osmosis of water must occur for the solutions to reach equilibrium.
A solution can be both hyperosmotic and isotonic.[1] For example, the intracellular fluid and extracellular can be hyperosmotic, but isotonic - if the total concentration of solutes in one compartment is different from that of the other, but one of the ions can cross the membrane, drawing water with it and thus causing no net change in solution volume.
ah wait heres a better explanation
http://books.google.com.au/books?id=gOmpysGBC90C&pg=PT94&lpg=PT94&dq=why+do+solutions+of+penetrating+solutes+have+zero+tonicity&source=bl&ots=PNUdgZTbUh&sig=Zs5OSFBrctZ8YR6MZEcLv24O5yc&hl=en&ei=d0CSS6DkM5WekQWVyZyDDQ&sa=X&oi=book_result&ct=result&resnum=8&ved=0CCcQ6AEwBw#v=onepage&q=&f=false
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Hypotonic - a solution with less solute than solvent
Hypertonic - a solution with more solute than solvent (think someone who is hyper/hyperactive = lots of sugar)
I dont think this is an accurate definition (as nearly all solutions have more solvent particles then solutes). Hypotonic solution means another solution with a lower concentration of solutes RELATIVE to the solution in question (usually solutions on 2 diff sides of membranes), and hypertonic means the same thing except higher conc. relative to solution in question.
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Thanks again, Truelight and Qshyrn for the even more detailed explanations :)
mmm, i got more questions.... sorry why am i so noob :(
here goes:
is the following sentence correct?
When placed in water, wilted plants lose their limpness because of osmosis of water into the plant cells.
thanks.. :)
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Thanks again, Truelight and Qshyrn for the even more detailed explanations :)
mmm, i got more questions.... sorry why am i so noob :(
here goes:
is the following sentence correct?
When placed in water, wilted plants lose their limpness because of osmosis of water into the plant cells.
thanks.. :)
yes correct, the osmosis restores the turgidity(stiffness due to water) of the cells
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Thanks!!!!!!!! :)
also..... is Osmosis the net movement of water from a region of low concentration of water to a region of high concentration of water?
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well yep if its distilled water.. then you have effectively 0 concentration of non-penetrating solutes... vs the 280 mosmolar or wateva in the plant cells.... so due to the concetration gradient.. the net movement of water flows into the cells.. and because it has the cell wall, it can stand the pressure so there isn't lysis and the plant cells swell
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Thanks!!!!!!!! :)
also..... is Osmosis the net movement of water from a region of low concentration of water to a region of high concentration of water?
no(other way around). movement of water from a region of HIGH CONCENTRATION of WATER to a region with a LOW CONCENTRATION OF WATER.
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ahh okay, thanks guys!!
i was completely confused, lolll :P
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and.. the scientific term to describe the effect of a hypertonic (hyper-osmotic) solution on plants cells is crenated, right?
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hm yeah i like to look at it in terms of solute concentration
so osmosis is the net movement of water molecules from a low solute concentration to high solute concentration...
yeah crenate... shrink..
and you can have hyper osmotic solutions but are isotonic...and solutions can be iso-osmotic without being isotonic......
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and.. the scientific term to describe the effect of a hypertonic (hyper-osmotic) solution on plants cells is crenated, right?
nah, for plant cells the better word is PLASMOLYSIS (i think) , because the cell walls of plants dont exactly sshrink only the membrane shrinks away from the cell wall
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oh yeah lol!
pfft who cares about plants...
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arhh, i seee!! so plasmolysis is the better word.. i saw shrink and crenate in some books though, um, so do i usually use plasmolysis to describe any effect caused by hypertonic?
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nah plasmolysis is just plants
wait maybe i shouldnt say that... in some other cases... but generally.. plants lol
i googled plasmolysis bacteria and yeah they can undergo plasmolysis too...
i think basically crenation is animal cells and organisms with a cell wall like plants undergoes plasmolysis
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arhh, i seee!! so plasmolysis is the better word.. i saw shrink and crenate in some books though, um, so do i usually use plasmolysis to describe any effect caused by hypertonic?
id use crenated in nonplant cells. for plant cells id write" the membrane shrinks away from the cell wall and the cell becomes plasmolysed"
im no biology nerd but thats what i think...
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yeah i don't think they will be pedantic about it
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okok, plasmolysed => for plant cell's hypertonic effect, whereas crenated => for animal cell's hypertonic effect.
awesome, thanks guys!! From you I have so much to learn, seriously
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lol... i thought this stuff was in the textbooks.... obviously not? lol
what do u wanna do monokekie?
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I have an extremely strong tendency to fall asleep when i have a textbook opening right infront of me, it took me 4 weeks to get through half a chapter. You guys have this ability to explain better than those textbooks, and i am not kidding :)
i dunno what i want to do yet o.O that's why i am doing biomed, andd its so cool gives me more time to decide waste.
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so ur doing biomed now? 1st yr? or yr 12 with bio planning on doing biomed
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I am a fresherman 1st year biomed undergrad, :)
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lol fresherman
awesome... goodluck
yeah u have plenty of time to decide... and anyway ur course is set out pretty much exact with only a few electives... just wait until 3rd yr and then u can choose wateva
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haha, i know, not many choices, but at least i have time to decide :)
Also, thanks! good luck to you too :P
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haha, i know, not many choices, but at least i have time to decide :)
Also, thanks! good luck to you too :P
thanks lol ill need it...
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Monokekie!! Is that the second ILT test for Bio: Cells and Organisms :P?
I'm doing it too hahaha! :D
haha cool :) good luck with that!
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'Plant cells and bacterial cells avoid bursting in hypotonic surroundings by their strong cell walls. These allow the buildup of turgor within the cell. When the turgor pressure equals the osmotic pressure, osmosis ceases.'
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nowonder i got this wrong :), haha thanks TL ~
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np ... lol i was getting lazy so i just copied it from somewhere that put it in a nice sentence for me
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oh yeah lol!
pfft who cares about plants...
+100000000000000 OH YEAAAAAAAAH :P
I have an extremely strong tendency to fall asleep when i have a textbook opening right infront of me, it took me 4 weeks to get through half a chapter. You guys have this ability to explain better than those textbooks, and i am not kidding :)
i dunno what i want to do yet o.O that's why i am doing biomed, andd its so cool gives me more time to decide waste.
Cell biology is probably the best part of first year biology. Wait till you get to the Zoology and Botany component ;)
*evil laughter* :2funny:
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wait, Zoology and botany...? so they are even harder....?.... Edmund is this even possible for me to get good grades for Bio?
Life sucks T^T
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kekie..don't you like bio??? :buck2:
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oh yeah, i liked bio :(
I think i still do, yup, i will force myself to love bio, like what i did to chem last year!
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If you love Zoology and Botany, you'll own the exam like username did ;D
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I can answer C - No, because some chromosomes are bigger than others and contain more genes.
Sorry, but I can't really answer the first two because that's unit four for me.
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Lol, but our school skipped most of mitosis! I think we only did chapters 1-5 of unit 1 or something like that.
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In the image attached: Where in the body does process B occur, How could you account for the difference in the sequence of the symbols in the final product compared with the sequence in the protein in the food eaten? Would other sequences be possible? Explain.
Thanks :)
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Haha another funny NOB question. Okay process B is protein synthesis, agreed? It's a dumb question, because protein synthesis occurs in every cell in the body (I doubt there are exceptions). The amino acid sequence is altered because the protein ingested is likely to not be functional within the human body hence a different protein needs to be made. Other sequences would be possible as the AAs can be arranged differently to make various proteins.
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Haha another funny NOB question. Okay process B is protein synthesis, agreed? It's a dumb question, because protein synthesis occurs in every cell in the body (I doubt there are exceptions). The amino acid sequence is altered because the protein ingested is likely to not be functional within the human body hence a different protein needs to be made. Other sequences would be possible as the AAs can be arranged differently to make various proteins.
Thank you so much! :)
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hmm lol the first reaction when i saw the picture was...
protein in food is hydrolysed... and it renatured
my reasoning is it says protein in food eaten, so the protein is already there and its the same peptides but in a different arrangement
although i might be wrong and aleitu1 is right lol
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Yeah, which is what I was saying. Process A is digestion or protein catabolism, process B is protein synthesis.
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yeah but your not really synthesizing protein, its already there
i would call it 'reforming' or something like that
actually... u can call protein synthesized... but i get an image of 'from scratch'
actually your right... after a quick search of what synthesize means lol
http://en.wiktionary.org/wiki/synthesize
it must be the 4 hours of sleep i got
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Yeah, I also understand what you are trying to say.