The tag has no usage guidance.

learn more… | top users | synonyms

0
votes
0answers
15 views

Do hydrogen ions contribute to water potential?

I was thinking about lysosomes and how they maintain an acidic pH inside themselves by pumping H+ ions from the cytosol. Do hydrogen ions set up a concentration gradient that causes water to move by ...
1
vote
0answers
8 views

Oncotic (Osmotic Pressure) in the blood pressure

I just wanted to ask, why is the oncotic pressure more negative in the blood plasma even though the hydrostatic pressure is higher since the blood comes from the pumping of the heart?
0
votes
1answer
70 views

Why is it not advisable for humans to drink distilled water? [duplicate]

Distilled water is pure and it does not contain any minerals, so may not be advisable for drinking. Although laboratory made distilled water is completely pure, industry made water may still contain ...
0
votes
1answer
64 views

Why is the swelling of bread when placed in water not considered to be caused by osmosis? [closed]

Why is bread swelling up when placed in water not considered to be caused by osmosis? Is there a property of water that should make it leave the bread instead of enter?
2
votes
1answer
168 views

Osmolarity vs. Tonicity

We're learning about osmoregulation in AP Biology and the terms Tonicity and Osmolarity are really confusing me. I watched this video on Khanacademy to try to understand what the difference is, and ...
5
votes
1answer
60 views

Do saltwater fish need to drink? [duplicate]

In my biology class we got the question if saltwater fish need to drink. We need to use the term osmosis, but I cannot think of a valid answer and we were allowed to ask help.
1
vote
1answer
59 views

Trees ability to transport water [duplicate]

How can trees be able to transport hundreds of liters of water all the way up to the crown and out in the leaves?
0
votes
0answers
35 views

Experiments on effects of RBC in solutions of different tonicity

In hypotonic solution, it appeared to be clearly visible, hemoglobin accumulated at the bottom of tube. For isotonic, it wasn't clear and hemoglobin settled on the bottom. And hypertonic, it appeared ...
1
vote
1answer
389 views

When does DIFFUSION occur and not OSMOSIS, and the otherwise?

For example, I do know that red blood cells have both the Na+/Cl- co-transporter and Aquaporin (water channel) that allows both Na/Cl and water molecules to pass through. But why in biology textbooks ...
1
vote
1answer
25 views

Is the PCT of the nephrons of the kidneys of marine vertebrates to minimize the natural tendency for exosmosis?

For marine vertebrates, the concentration of salts outside their body (in the water, that is) is more than that inside their body. So, there is a natural tendency for exosmosis to occur. To minimise ...
2
votes
2answers
114 views

Osmotic Pressure and Enzyme Activity

Is it true that in an enzyme-catalyzed reaction, the rate of reaction does not vary with varying osmotic pressure? Instead of just a true or false answer, why does it, or why does it not vary with ...
4
votes
1answer
791 views

What happens to the red blood cell in CaClâ‚‚ solution?

Here's the problem: One red blood cell is placed in a hypertonic solution of NaCl, another is placed in a solution of CaCl2 equimolar with the NaCl solution. What would you expect to happen and why? ...
3
votes
1answer
9k views

What is the difference between osmotic potential and osmotic pressure?

Which term is used to calculate water potential? Does osmotic potential mean the same as solute potential?
3
votes
2answers
1k views

Does osmosis take place in prokaryotic cells?

As far as I know, osmosis occurs in Eukaryotic cells, and I'm wondering if it could take place in prokaryotic cells too.
5
votes
2answers
5k views

Diffusion of Hypotonic solution into solution with glucose and starch

Cell walls are selectively permeable to ions and organic molecules. Sometimes the selectivity is passive and a reflection of the physical laws governing diffusion. We can do simple experiments that ...
5
votes
1answer
185 views

How does a Na+/H+ antiporter drive osmosis in this “osmotic motor”?

This recent paper in Cell describes a cancer cell using osmotic pressure to move in confined spaces. The cell preferentially inserts Na+/H+ antiporters in the leading membrane. I want someone to ...