Understanding Tonicity and Cell Membrane Dynamics

What happens to a chicken egg when soaked in vinegar for 24-48 hours?

The eggshell dissolves, leaving the egg surrounded by two tightly held membranes.

What property of the egg membrane allows certain molecules to pass through?

The membrane is selectively permeable.

How do substances move through the egg membrane?

Substances move from areas of higher concentration to areas of lower concentration through diffusion.

What type of molecules can pass easily through the egg membrane?

Water and small molecules can pass easily, while larger molecules like sugar cannot.

What occurs when the concentration of molecules on both sides of the membrane is equal?

The overall concentration remains in equilibrium, with equal concentrations on both sides.

What is the effect of a hypotonic solution on a cell?

Water moves into the cell, causing it to swell.

What is the effect of a hypertonic solution on a cell?

Water moves out of the cell, causing it to shrink.

What happens in an isotonic environment regarding water movement?

Water moves in and out of the cell at equal rates, maintaining equilibrium.

What does it mean for a membrane to be selectively permeable?

It allows certain molecules, like water, to pass through while blocking larger molecules and solutes.

How does a hypotonic solution affect the movement of water in a cell?

In a hypotonic solution, water moves into the cell, increasing its volume.

How does a hypertonic solution affect the movement of water in a cell?

In a hypertonic solution, water moves out of the cell, decreasing its volume.

What is the effect of an isotonic solution on a cell's size?

The cell remains the same size as water moves in and out at equal rates.

Are cell membranes rigid or flexible?

Cell membranes are flexible.

How does the flexibility of cell membranes help in a hypotonic solution?

Flexibility allows the membrane to accommodate swelling caused by water intake.

How does the flexibility of cell membranes help in a hypertonic solution?

Flexibility prevents the cell from rupturing or becoming too rigid as it shrinks.

What is the role of diffusion in the movement of substances across the egg membrane?

Diffusion allows substances to move from areas of higher concentration to lower concentration until equilibrium is reached.

What is the significance of the two membranes surrounding the egg after the shell is dissolved?

They mimic the selectively permeable nature of human cell membranes.

What happens to the concentration of solutes in a cell placed in a hypotonic solution?

The concentration of solutes inside the cell becomes lower as water enters.

What happens to the concentration of solutes in a cell placed in a hypertonic solution?

The concentration of solutes inside the cell becomes higher as water leaves.

What is osmosis?

Osmosis is the movement of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

How does the movement of water in and out of a cell relate to tonicity?

Tonicity describes the effect of the surrounding solution on the movement of water into or out of the cell.

What are the three types of tonicity that affect cells?

Hypotonic, hypertonic, and isotonic.

What is the main difference between active transport and passive transport?

Active transport requires energy to move molecules against their concentration gradient, while passive transport moves molecules from areas of high concentration to low concentration without energy.

How does osmosis differ from the movement of glucose in the naked egg experiment?

Osmosis involves the movement of water through a selectively permeable membrane, while glucose, being a larger molecule, may require facilitated diffusion or active transport and cannot pass through the membrane.

What happens to a naked egg placed in 100% corn syrup?

The egg decreases in mass (-84.9%) and appears shriveled because the corn syrup is hypertonic, causing water to move out of the egg through osmosis.

Why does water move out of the egg when placed in corn syrup?

Water moves out of the egg due to selective permeability, from an area of high water concentration inside the egg to a low water concentration in the corn syrup.

What is the effect of placing a naked egg in distilled water?

The egg increases in mass (+15.2%) and swells because distilled water is hypotonic, having a lower concentration of solute than inside the egg.

How does water move into the egg when placed in distilled water?

Water moves into the egg by osmosis, traveling from the high water concentration outside the egg to the low water concentration inside.

What observation occurs when a naked egg is placed in a 20% corn syrup solution?

The egg's mass stays roughly the same (+0.5%) and appears full but not as firm, indicating that the solution is isotonic.

What does it mean for a solution to be isotonic compared to the egg?

An isotonic solution has approximately equal solute concentrations on both sides of the egg's membrane, allowing water to diffuse in both directions at equal rates.

What is the significance of equilibrium in the context of osmosis?

Equilibrium refers to the state where the concentrations of solute are equal on both sides of a membrane, resulting in no net movement of water.

What role does selective permeability play in the movement of water and solutes?

Selective permeability allows certain molecules, like water, to pass through the membrane while restricting larger molecules, such as glucose.

What are the terms used to describe the concentration of solutions in relation to the egg?

Hypertonic (higher solute concentration), hypotonic (lower solute concentration), and isotonic (equal solute concentration).

In the context of osmosis, what direction do water molecules move in a hypertonic solution?

Water molecules move out of the egg into the hypertonic solution, leading to the egg shrinking.

What direction do water molecules move in a hypotonic solution?

Water molecules move into the egg from the hypotonic solution, causing the egg to swell.

What is the observation and explanation for the egg in a hypertonic solution?

The egg shrinks due to water moving out, as the hypertonic solution has a higher solute concentration than the egg.

What is the observation and explanation for the egg in a hypotonic solution?

The egg swells as water moves in, since the hypotonic solution has a lower solute concentration than the egg.

What happens to the egg's mass in an isotonic solution?

The egg's mass remains stable as water diffuses in and out at equal rates.

What is the importance of the size of molecules in passive transport?

Smaller molecules can pass through the membrane more easily, while larger molecules may require facilitated diffusion or active transport.

What is the role of diffusion in the movement of molecules?

Diffusion is the process where molecules move from areas of high concentration to low concentration, contributing to the equilibrium.

How can you visually represent the effects of different solutions on a naked egg?

By drawing labeled diagrams showing water movement in hypertonic, hypotonic, and isotonic solutions.

What happens to solute concentrations when a cell is placed in a hypertonic solution?

The solute concentration inside the cell cannot equalize fully with the hypertonic solution due to selective permeability.

What is the relationship between solute concentration and water movement?

Water moves from areas of low solute concentration to high solute concentration to achieve equilibrium.

What is the label for a solution with equal solute concentrations inside and outside the egg?

Isotonic (20% Corn Syrup): Equal Solute Concentrations (Equilibrium).

Which types of molecules can pass directly through the lipid bilayer?

Oxygen, Carbon Dioxide, and Water.

What common characteristic do molecules that pass through the lipid bilayer directly share?

They are small and not charged (not ions).

How do ion channels open and close?

They receive signals based on chemical and electrical conditions within and outside the cell.

Why do ions like Potassium need to use ion channels?

Because they cannot pass through the membrane due to their charge.

Do protein pumps require energy? What type of transport is this?

Yes, they require energy and are an example of active transport.

What is the function of aquaporins?

Aquaporins allow the passage of water through the membrane.

What type of cell transport do aquaporins facilitate?

Facilitated transport.

Do gluT transporters require energy? What type of transport is this?

No, they do not require energy and are an example of facilitated transport.

How do enzymes exit the cell? What type of transport is this?

Enzymes exit the cell through exocytosis.

Can green dots and blue diamonds pass through the membrane on their own?

No, neither can pass through the membrane on their own.

What does the presence of leakage channels allow?

Specific molecules (green dots through green channels and blue diamonds through blue channels) to pass through.

What type of diffusion occurs with leakage channels?

Facilitated diffusion.

How can the rate of molecules moving across the membrane be increased?

By increasing the concentration gradient, adding more channels, increasing temperature, changing the type of molecule, or decreasing the distance by shrinking the cells.

How are gated channels different from leakage channels?

Gated channels open and close, while leakage channels are always open.

What type of transport is likely associated with gated channels?

Active transport, which requires energy.

What is a solution?

A uniform mixture of two or more substances.

What are the two components of a solution?

The solute (dissolved substance) and the solvent (substance the solute is dissolved into).

In living systems, what is frequently the solvent in a solution?

Liquid water.

Provide an example of a solute, solvent, and solution.

Solute = Salt, Solvent = Water, Solution = Salt Water.

What process do cells use to maintain a stable internal environment?

Homeostasis.

What does it mean for a cell membrane to be selectively permeable?

It controls the movement of substances in and out of the cell.

How do cells respond to different solutions regarding water movement?

They may absorb or release water to balance the concentration of solutes inside and outside.

What is diffusion?

The movement of molecules along concentration gradients from areas of high concentration to low concentration.

What is osmosis?

The movement of water across a selectively permeable membrane, depending on solute concentration.

What does isotonic mean in terms of solute concentration?

Same concentration of solute as compared to something.

What happens to a cell in an isotonic solution?

There is no change to size or mass; water moves equally in and out.

What does hypertonic mean in terms of solute concentration?

More concentration of solute as compared to something.

What happens to a cell in a hypertonic solution?

The cell would secrete water and shrink.

What does hypotonic mean in terms of solute concentration?

Less concentration of solute as compared to something.

What happens to a cell in a hypotonic solution?

The cell would absorb water and grow.

What is the relationship between concentration gradients and the movement of molecules?

Molecules move from areas of high concentration to low concentration.

How do scientists compare solvent concentrations in solutions?

They use terms like isotonic, hypertonic, and hypotonic.

What is the effect of a hypertonic solution on cell size?

The cell shrinks due to water loss.

What is the effect of a hypotonic solution on cell size?

The cell grows due to water absorption.

What is the significance of concentration gradients in osmosis and diffusion?

They determine the direction of water and solute movement across membranes.

What is the prefix meaning of 'iso'?

Equal (Same).

What is the prefix meaning of 'hyper'?

Above (more).

What is the prefix meaning of 'hypo'?

Below (less).

What determines the direction of water movement in relation to a cell and solution?

The direction of water movement is determined by the concentration of dissolved solute or water in the cell compared to the solution.

What does it mean if a solution is hypotonic compared to a cell?

A hypotonic solution has a lower concentration of solutes than the cell, causing water to move into the cell.

What does it mean if a solution is hypertonic compared to a cell?

A hypertonic solution has a higher concentration of solutes than the cell, causing water to move out of the cell.

What does it mean if a solution is isotonic compared to a cell?

An isotonic solution has equal concentrations of solutes compared to the cell, resulting in no net movement of water.

In the grocery store example, how does the misted water compare to the vegetables?

The misted water is hypotonic compared to the vegetables, as it has a higher concentration of water and lower concentration of solutes.

Why do vegetables absorb water from the misted water?

Vegetables absorb water because the misted water is hypotonic, leading to water movement into the vegetables.

What happens to a slug when salty water is sprinkled on it?

The slug shrinks and shrivels because it is hypotonic compared to the salty water, causing it to lose water.

How does the slug compare to the salty water?

The slug is hypertonic compared to the salty water, having a higher concentration of water and lower concentration of solutes.

What occurs when a dry raisin is placed in water?

The raisin expands and becomes plump because it is hypertonic compared to the water, causing water to move into the raisin.

Why does water move into the raisin when placed in water?

Water moves into the raisin because the raisin has a higher concentration of solutes and lower concentration of water.

What is the relationship between a patient's cells and the IV fluid designed to hydrate them?

The patient's cells and IV fluid are isotonic, meaning they have equal concentrations of water and solutes.

What happens to cells when they are in an isotonic solution?

Cells do not shrink or swell in an isotonic solution, indicating equal amounts of water and solutes.

What is the effect of a hypertonic solution on a cell?

A hypertonic solution causes a cell to lose water, leading to cell shrinkage.

What is the effect of a hypotonic solution on a cell?

A hypotonic solution causes water to enter the cell, leading to cell swelling.

How can you identify if a solution is hypertonic, hypotonic, or isotonic?

By comparing the concentration of solutes in the solution to that in the cell.

What happens to the concentration of solutes in a cell when placed in a hypotonic solution?

The concentration of solutes in the cell decreases as water enters the cell.

What happens to the concentration of solutes in a cell when placed in a hypertonic solution?

The concentration of solutes in the cell increases as water leaves the cell.

How do cells maintain their shape in an isotonic environment?

Cells maintain their shape in an isotonic environment because there is no net movement of water.