Login

Join for Free!
61664 members


Its the Freshman again !! I NEED HELP ON OSMOSIS

Discussion of all aspects of cellular structure, physiology and communication.

Moderator: BioTeam

Its the Freshman again !! I NEED HELP ON OSMOSIS

Postby blondetontochic » Fri Nov 03, 2006 1:22 am

Okay so i totally dnt get osmosis ! Its so confusing and i dont understand the phases of cell reproduction !!! HELP ME PLEASE !!! :roll:
blondetontochic
Garter
Garter
 
Posts: 2
Joined: Thu Oct 26, 2006 2:44 am

Cell reproduction

Postby mafiaparty303 » Fri Nov 03, 2006 1:32 am

Ok so i'm not sure about osmosis but im pretty sure its the want for equalibrium bettween two substnaces in this case cells, a cell that contains more salt lets say than the surrounding fluid will have its salt absorbed by the less salty liquid around the cell,

as for cell reproduction I remember there are dirfferent phases metaphase, anophase and other ones I dont remeber, the cell prpares to divide by unraveling the DNA in the chromosomes and forming half chromosomes then duplicates are made and the cell begins to split apart because of the spindels pulling at the half chromosomes then the cell splits and you have a new cell this is a VERY rough explanation for what happenes, try searching it on google you'll probably find some images with labels and everyhintg
mafiaparty303
Garter
Garter
 
Posts: 5
Joined: Fri Nov 03, 2006 1:15 am

Postby SU_reptile » Fri Nov 03, 2006 5:05 pm

cell cycle

Tell me what you don't understand in osmosis? I will try to explain it to you.
SU_reptile
Coral
Coral
 
Posts: 145
Joined: Mon May 01, 2006 6:38 pm
Location: Katowice - Poland

Postby keef » Fri Nov 03, 2006 7:42 pm

Osmosis is the movement of water through a semipermeable membrane from a region of low solute potential to a region of high solute potential (or equivalently, from a region of high solvent potential to a region of low solvent potential). The semipermeable membrane must be permeable to the solvent, but not to the solute, resulting in a pressure gradient across the membrane. Osmosis is a natural phenomenon. However, it can be artificially opposed by increasing the pressure in the section of high solute concentration with respect to that in the low solute concentration. The force per unit area required to prevent the passage of solvent through a selectively-permeable membrane and into a solution of greater concentration is equivalent to the turgor pressure. Osmotic pressure is a colligative property, meaning that the property depends on the concentration of the solute but not on its identity.
Keith :)
User avatar
keef
Coral
Coral
 
Posts: 117
Joined: Sun Sep 10, 2006 3:56 pm
Location: Singapore


Postby keef » Fri Nov 03, 2006 7:43 pm

and if u wanna know more about osomotic pressure, just pm me. i have lotsa notes on it. when i was in junior college, i did alot of calculations on osomosis.
Keith :)
User avatar
keef
Coral
Coral
 
Posts: 117
Joined: Sun Sep 10, 2006 3:56 pm
Location: Singapore

Postby dipjyoti » Sat Nov 04, 2006 9:18 am

osmosis explanation:- Consider a permeable membrane, such as visking tubing, with apertures small enough to allow water molecules, but not larger molecules, to pass through. Suppose the membrane is in a volume of pure water. At a molecular scale, every time a water molecule hits the membrane, it has a defined likelihood of passing through. In this case, since the circumstances on both sides of the membrane are equivalent, there is no net flow of water through it. However, if there is a solution on the other side, that side will have fewer water molecules and thus fewer collisions with the membrane. This will result in a net flow of water to the side with the solution. Assuming the membrane does not break, this net flow will slow and finally stop as the pressure on the solution side becomes such that the diffusion in each direction is equal. Osmosis can also be explained via the notion of entropy, from statistical mechanics. As above, suppose a permeable membrane separates equal amounts of pure solvent and a solution. Since a solution possesses more entropy than pure solvent, the second law of thermodynamics states that solvent molecules will flow into the solution until the entropy of the combined system is maximized. Notice that, as this happens, the solvent loses entropy while the solution gains entropy. Equilibrium, hence maximum entropy, is achieved when the entropy gradient becomes zero.


Cell division (or local doubling) is the process by which a cell, called the parent cell, divides into two cells, called daughter cells. Cell division is usually a small segment of a larger cell cycle. In meiosis however, a cell is permanently transformed and cannot divide again.

Cell division is the biological basis of life. For simple unicellular organisms such as the Amoeba, one cell division reproduces an entire organism. On a larger scale, cell division can create progeny from multicellular organisms, such as plants that grow from cuttings. But most importantly, cell division enables sexually reproducing organisms to develop from the one-celled zygote, which itself was produced by cell division from gametes. And after growth, cell division allows for continual renewal and repair of the organism.

The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information which is stored in chromosomes must be replicated, and the duplicated genome separated cleanly between cells. A great deal of cellular infrastructure is involved in keeping genomic information consistent between "generations".
User avatar
dipjyoti
Coral
Coral
 
Posts: 142
Joined: Thu Sep 21, 2006 7:04 am
Location: CALCUTTA;INDIA

Postby sachin » Sat Nov 04, 2006 8:34 pm

I ll try to tell you simply

If you have to surivive you have to drink sufficient water.
If you do not then U ll get dehydrated.
In acces you will start to lose water.

that means water should be in adequqte quantt in body.

Cell are same; they ve to mentain water salt balance.
and they do it by osmosis.

Other part you refer above posts.
Senior Education Officer, BNHS, India. www.bnhs.org

Bitter Truth!
Who says reason for world war IV will be Petrol?
Reason lies in two words "Me and Mine".
User avatar
sachin
King Cobra
King Cobra
 
Posts: 1517
Joined: Mon Jan 30, 2006 12:39 pm
Location: MUMBAI / INDIA

Postby daniel.kurz » Wed Nov 08, 2006 6:10 pm

Example of it is if you go into the ocean you get dehydrated. Why? Because the water outside your body has a higher salinity than your "juices". Therefore, the body expels water into the ocean to raise the salinty.

Your body is trying to become isotonic. You would say that your body is hypotonic and the salt water is hyptertonic.
daniel.kurz
Coral
Coral
 
Posts: 155
Joined: Fri May 19, 2006 1:47 am


Return to Cell Biology

Who is online

Users browsing this forum: No registered users and 0 guests