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Cell Permability

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Cell Permability

Postby Host » Sun Mar 19, 2006 8:33 pm

A few quest. i've answered but was wondering others take - from the back of campbell and reece 7th ed. (prac. quest. for my test this thur)

1. A patient loses alot of blood and a large amount of water is directly injected into his viens, the result of this will be?

- it will have fatal effects b/c the persons RBC's (red blood cells) will be hypertonic to the body fluids with the added water, and the cells will lyse

i said hypertonic, but in my book its got a digarm with ANIMAL cells being hypotonic with h20 added (typ-o maybe?)

2. __ would readily move through a synthetic membrane
- glucose
- testosterone (my answer)
- ATP
- H+
- CL-

- im positive its not glucose, h+, or Cl-, but my book says nothing concerning ATP, yet it drives all cell work so wouldnt it be logical that it would move through any memb, organic or syn...?

3. Phospholipids found on the inside of the enoplasmic reticulum membrane are most likely to be found where when they reach thier final cellualr desitination?

- in the cytoplasm
- outside of the golgi apparatus
- outside the cell (my answer)
- inside the cell membrane
- outside the cell membrane

The hardest one i cant get
4. Celery stalks immersed in fresh water for several hours become stiff and hard, stalks left in a salt solution become limp and soft, from this we can deduce that the cells of the celery stalks are

- hypertonic to fresh water and hypotonic to the salt solutoin (my answer)

- hypotonic to fresh water and hypertonic to the salt soltuion

( i dont understand these two principles... hypertonic/hypotonic, any help?)

5. A cell in a healthy plant is ____ b/c the cytoplasm if the plant cell is ___ relative to the warer environment of the soil (im pretty postive on this one)

- lysed/hypertonic
-flaccid/isotonic
- turguid/hypertonic ( my answer)
- plasmolyzed/isotonic

6. And a ques. from left field that we didnt cover, i guessed so this may be wrong

== Mutant cells lacking coated pits would most likely be...?
- deficient in receptor mediated endocytosis (my answer)
- unable to adapt to the cold
- characterized by a smooth surface on both sides of the bilayer
- involved in steroid synthesis
- unable to actively transport ions into the cell


any help on these would be appreciated, ive gotta get some of these patters/principles down b/c im not doing great in this class, mostly im having trouble with hypertonic/hypotonic...the book explains it well but gives no applied examples, only these ques... thanks for ur time

- host
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Postby Host » Sun Mar 19, 2006 10:11 pm

so am i right on all of'em or does anyone not know?
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Postby Mooks » Mon Mar 20, 2006 4:13 am

1. A patient loses alot of blood and a large amount of water is directly injected into his viens, the result of this will be?

Im not sure exactly what you mean(in terms of the Text books answer), but i would say that they may be refering to the injected solution as being hypotonic (Obviously) Water will move along a concentration gradient INTO the cell causing cells to swell and possibly burst.

MAYBE the DIAGRAM is showing the EFFECT the injected solution will have ON the cell. :?

2. __ would readily move through a synthetic membrane

Look more into what is a SYNTHETIC Membrane.
A synthetic membrane is made up of LARGE polymers...hence the name "Synthetic" and is used industraly for treating/cleansing wastewater and is capable of separating out a variety or undesirable substances, including toxic molecules. What makes up pure water?

now look at your list...if the solution passed through was intended for DRINKING/as purified water...which of the substances would you expect in PURE water?

definitely NOT glucose as the molecule is too big to pass through the pores.

It can't be testosterone.....can u imagine drinking testosterone? *ugh*

Possibly ATP...but keep in mind that ATP is produced IN cells

I would say that it IS H+ since water consists of free moving H+ (H3O+) and OH- ions.

Wouldnt be Cl- since pure chlorine is Toxic.

Now im not ENTIRELY 100% sure but that is how i would answer it.


4. Celery stalks immersed in fresh water for several hours become stiff and hard, stalks left in a salt solution become limp and soft, from this we can deduce that the cells of the celery stalks are

The cells would be Hypertonic. Think of the cellery cells as having more yummy nutrients and salts than it would have water You put it in Freshwater which has tons of water molecules (ie. it is HYPOtonic) water will diffuse INTO the celery cell until concentration of water in and out of celery sticks are EQUAL....this would make the celery stick hard and stiff as it is just "BLOATED" if you know what i mean.

Kinda like when we eat......eat too much for dinner and after dinner you can't move. Don't eat all day and you feel sapped of energy by the end of the day. Same reaction observed in the celery stick.

When it was placed in a Salt solution...the celery lost water since it was moving OUT of the cells, this would explain the celery becoming limp and soft.



I couldnt understand what you meant by question 5....you might have been typing in a rush and #6 i have no idea.

I have this really helpful diagram a drew up that may help you understand Hypertonic, hypotonic and Isotonic more easily if you are more of a Visual learner like me, just let me know and il send it to ya.
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Postby Host » Mon Mar 20, 2006 10:20 pm

hey mooks, yeah im still not understanding the hypo/hypertonic thing, ive got a good digram in my book but with these ques. it seems to refute them...

ques. 1 more refers to the blood cells, ie. will the "RBCs" be ___ to the solution... i know they will lyse but is that hypo or hyper? in my digram it lists hypo, but for the defeiniton of hyper (lower water concentration than other side of cell membrane) it describes this process of water going into the cell...? i agree that its hypotonic but wtf is hypertonics definiton ( i.e hyperosmotic solution; higher solute concentration { lower water concentration) than other side of cell membrane pretain to/?

3 i still cant figure out

The one about a syn. membrane i've lost my notes it seems >:O (i'll get back to that one)

Please some enlightened minds, shed some thought, college student in need :?
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Postby Mooks » Mon Mar 20, 2006 10:48 pm

Host wrote:ques. 1 more refers to the blood cells, ie. will the "RBCs" be ___ to the solution... i know they will lyse but is that hypo or hyper? in my digram it lists hypo, but for the defeiniton of hyper (lower water concentration than other side of cell membrane) it describes this process of water going into the cell...? i agree that its hypotonic but wtf is hypertonics definiton ( i.e hyperosmotic solution; higher solute concentration { lower water concentration) than other side of cell membrane pretain to/?


Ooooh ok....no the book is right, you've just got yourself mixed up.

If the cell Lysed that means that the cell WAS HYPERtonic to the solution. this indicates that water moved INTO the cell because the cell had a lower concentration of water compared to the injected solution. The injected solution would have then been HYPOtonic.

If the cell appeared to have shrivelled, it would indicate that water moved OUT of the cell so therefore the cell WAS HYPOtonic and the surrounding solution is HYPERtonic.


HYPO-tonic Solutions- Those solutions that cause the cells(which is HYPER-tonic to the solution) in the solution to SHRINK....

HYPER-tonic Solutions Those solutions that cause the cells(which is HYPOtonic to the solution) in the solution to SWELL/appear crenated

Therefore, the cell will Red Blood Cell will be HYPERtonic to the solution since the SOLUTION is HYPOtonic...............[b/]

hope i havent confused you even more
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Re: Cell Permability

Postby ipsha03 » Thu Jul 14, 2011 4:25 pm

In osmosis, movement of solvent molecules occur from high conc. of solvent molecules to lower conc of solvent molecules across semi permeable membrane.
hypotonic solution- solution having low conc of solute molecule.
hypertonic solution- solution having high conc. of solute molecule.

blood cells have low osmotic potential while water injected has high osmotic potential. thus water enters the cell and results cell lysis.
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Postby ashish008Z » Mon Jul 25, 2011 4:58 am

i just want to ask in which chromosome of human life span is coded?
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