I bet you've all heard the expression, "Water is the universal solvent." Today, we're gonna talk about solvents, solutions, and how they relate to cell structure. A solution is a mixture, it's a homogeneous mixture, that has two basic parts, a solvent, and one or more solutes. Salt water is a solution. In that example, water is the solvent, salt is the solute. We often say that the solute is the substance that's dissolved in the solvent. But that's a very misleading way to define solute. So we're gonna come up with a better definition. In any solution, the solvent is that part in the greater quantity, and the solute can be one or more parts, those parts in the lesser quantity or quantities. For example, the air around us is a solution. It's a homogeneous mixture. 78% of the air around us is nitrogen, that's a solvent. 21% of the air is oxygen, that's one of the solutes. Then there's 1% other: Carbon-dioxide, argon, other gases. 01:37: Again, the solvent of a solution, is that part in the greater quantity. The solute could be one or more, and that's in a lesser quantity. In living systems, most often, the solvent is water. You and I are mostly water; plants, mostly water. If you look around us, all life on Earth is mostly water and we are the water planet. So we're gonna see how the solvent-solute ratio affects cells. Now, we're gonna look at them, in terms of a new word and that word is called 'tonicity.' Tonicity describes the amount of solute inside and outside of a cell. You remember that water moves through a semi-permeable membrane by the process of osmosis. It doesn't require cell energy, it just happens. You've experienced it happening when your fingers get wrinkled up, when you're swimming in the ocean. That's an example of water moving in and out of your cells, and you don't have any control of that. 02:56: You also see it happen on a hot summer day when a plant wilts. Water has left that central vacuole on the plant cell. The plant has no control over it. If you water the plant, it perks back up again. That movement of water into and out of the cells, of either animals or plants, is the process of osmosis. And we're gonna look at what happens to a cell. In these three pictures, the circle in the middle represents a cell when it's put in specific solutions. In an isotonic solution... X's, in this case, represent our solute, that which is dissolved in the water... In an isotonic solution, the prefix 'iso' means equal or the same, think isosceles triangle. The amount of solute out of the cell and inside the cell is equal. Thus saying, there's no change in the cell size. Water, this is a dynamic system, water keeps moving back and forth, but it doesn't move more one way or the other. So in an isotonic solution, solute out of the cell and solute inside the cell are equal, and the cell's size stays the same, and the amount of water inside stays the same. 04:26: In a hypotonic solution, think 'hypodermic,' below the skin, hypodermic. Hypotonic, the prefix 'hypo' means below or less than. The amount of solute outside of the cell, is less than the amount of solute inside of the cell. Another way to look at this, and sometimes this is easier, when it comes to remembering which way water moves, if I have less solute outside of the cell, then I have more water. And if I have more solute inside of the cell, then I have less water. Okay, now, remember, osmosis happens by itself. It's the movement of water from a higher concentration to an area of lesser concentration. More water, less solute. More solute, less water. In this case, the water outside of the cell is gonna move into the cell and the cell is going to get larger, as the water moves in. The cell will swell in a hypotonic solution. 05:52: In a hypertonic solution, you know if you're hyperactive, you got more energy than normal. So if you're a hypertonic solution, you have more solute above the normal amount of solute. If we look here, we still have the same amount of solute inside the cell, but we have twice as much on the outside. This is a hypertonic solution. Again, if we look at it from the concentration of water, we now have less water outside of the cell and we have more water inside of the cell. Water moves from a higher concentration to a lower concentration. So, now, the water's going to leave the cell. There's nothing that cell can do about it. It's osmosis. It just happens. And over time, the cell will shrink.

Question

I bet you've all heard the expression, "Water is the universal solvent." Today, we're gonna talk about solvents, solutions, and how they relate to cell structure. A solution is a mixture, it's a homogeneous mixture, that has two basic parts, a solvent, and one or more solutes. Salt water is a solution. In that example, water is the solvent, salt is the solute. We often say that the solute is the substance that's dissolved in the solvent. But that's a very misleading way to define solute. So we're gonna come up with a better definition. In any solution, the solvent is that part in the greater quantity, and the solute can be one or more parts, those parts in the lesser quantity or quantities. For example, the air around us is a solution. It's a homogeneous mixture. 78% of the air around us is nitrogen, that's a solvent. 21% of the air is oxygen, that's one of the solutes. Then there's 1% other: Carbon-dioxide, argon, other gases. 01:37: Again, the solvent of a solution, is that part in the greater quantity. The solute could be one or more, and that's in a lesser quantity. In living systems, most often, the solvent is water. You and I are mostly water; plants, mostly water. If you look around us, all life on Earth is mostly water and we are the water planet. So we're gonna see how the solvent-solute ratio affects cells. Now, we're gonna look at them, in terms of a new word and that word is called 'tonicity.' Tonicity describes the amount of solute inside and outside of a cell. You remember that water moves through a semi-permeable membrane by the process of osmosis. It doesn't require cell energy, it just happens. You've experienced it happening when your fingers get wrinkled up, when you're swimming in the ocean. That's an example of water moving in and out of your cells, and you don't have any control of that. 02:56: You also see it happen on a hot summer day when a plant wilts. Water has left that central vacuole on the plant cell. The plant has no control over it. If you water the plant, it perks back up again. That movement of water into and out of the cells, of either animals or plants, is the process of osmosis. And we're gonna look at what happens to a cell. In these three pictures, the circle in the middle represents a cell when it's put in specific solutions. In an isotonic solution... X's, in this case, represent our solute, that which is dissolved in the water... In an isotonic solution, the prefix 'iso' means equal or the same, think isosceles triangle. The amount of solute out of the cell and inside the cell is equal. Thus saying, there's no change in the cell size. Water, this is a dynamic system, water keeps moving back and forth, but it doesn't move more one way or the other. So in an isotonic solution, solute out of the cell and solute inside the cell are equal, and the cell's size stays the same, and the amount of water inside stays the same. 04:26: In a hypotonic solution, think 'hypodermic,' below the skin, hypodermic. Hypotonic, the prefix 'hypo' means below or less than. The amount of solute outside of the cell, is less than the amount of solute inside of the cell. Another way to look at this, and sometimes this is easier, when it comes to remembering which way water moves, if I have less solute outside of the cell, then I have more water. And if I have more solute inside of the cell, then I have less water. Okay, now, remember, osmosis happens by itself. It's the movement of water from a higher concentration to an area of lesser concentration. More water, less solute. More solute, less water. In this case, the water outside of the cell is gonna move into the cell and the cell is going to get larger, as the water moves in. The cell will swell in a hypotonic solution. 05:52: In a hypertonic solution, you know if you're hyperactive, you got more energy than normal. So if you're a hypertonic solution, you have more solute above the normal amount of solute. If we look here, we still have the same amount of solute inside the cell, but we have twice as much on the outside. This is a hypertonic solution. Again, if we look at it from the concentration of water, we now have less water outside of the cell and we have more water inside of the cell. Water moves from a higher concentration to a lower concentration. So, now, the water's going to leave the cell. There's nothing that cell can do about it. It's osmosis. It just happens. And over time, the cell will shrink.

Close
Question 1
When a plant is placed in pure distilled water, its cells will __________.
Responses
A shrinkshrink
B swellswell
Question 2
______________ describes the amount of solute inside and outside of a cell. The amount of a solute in the environmental solution compared to the amount of solute within the cell.
Responses
A TonicityTonicity
B SolvencySolvency
Question 3
The prefix "hypo" means _________.
Responses
A overover
B under

Please answer all 3 questions correctly

Answer 1

Question 1: B - swell

Question 2: A - Tonicity

Question 3: B - under

Answer 2

Question 1:

When a plant is placed in pure distilled water, its cells will __________.
A) shrink
B) swell

Answer: B) swell

Question 2:
______________ describes the amount of solute inside and outside of a cell. The amount of solute in the environmental solution compared to the amount of solute within the cell.
A) Tonicity
B) Solvency

Answer: A) Tonicity

Question 3:
The prefix "hypo" means _________.
A) over
B) under

Answer: B) under

Answer 3

Question 1:

When a plant is placed in pure distilled water, its cells will __________.
A) shrink
B) swell
- The correct answer is B) swell. When a plant cell is placed in a hypotonic solution (such as pure distilled water), where the solute concentration outside the cell is lower than inside, water will move into the cell through osmosis, causing the cell to swell.

Question 2:
______________ describes the amount of solute inside and outside of a cell. The amount of a solute in the environmental solution compared to the amount of solute within the cell.
A) Tonicity
B) Solvency
- The correct answer is A) Tonicity. Tonicity describes the concentration of solute inside and outside of a cell. It compares the amount of solute in the surrounding solution to the amount of solute inside the cell.

Question 3:
The prefix "hypo" means _________.
A) over
B) under
- The correct answer is B) under. The prefix "hypo" means below or less than. In the context of tonicity, a hypotonic solution has a lower solute concentration compared to the inside of the cell.