cellular

Which statement concerning osmosis and active transport is correct? A)Both endocytosis and active transport require cell energy.B)Active transport requires cell energy while osmosis does not.C)Neither faciliated diffusion nor osmosis requires cell energy.D)Diffusion of gases and other small molecules requires no energy on part of the cell.

B)Active transport requires cell energy while osmosis does not.

The movement of water through a selectively permeable membrane from an area of high concentration toPLUS low concentration.

osmosis

A solution that causes a cell to shrink because of the high concentration of solute in the solution surrounding the cell.

Hypertonic

The substance that dissolves the solute.

solvent

A solution that causes a cell to swell because of osmosis.

Hypotonic

The substance that is being dissolved by a solvent.

solute

he process by which water crosses a selectively permeable membrane is called A)osmosis.B)mitosis.C)meiosis.D)active transport.

A) osmosis

The picture shows an experimental set up for the process of osmosis.The potato has a cavity on top, as shown in the picture. Some sugar solution is poured into the cavity and the potato is placed in a beaker of water. After some time, it is observed that there is a rise in the level of liquid in the cavity. This confirms that A)water from the beaker has moved into the cavity.B)sugar has moved out of the sugar solution in the cavity.C)the sugar solution in the cavity has become more concentrated.D)there is equilibrium between the liquids in the beaker and the cavity.

A)water from the beaker has moved into the cavity.

Active Transport Passive Transport Both Osmosis Utilizes the semi-permeable membrane and transport proteins Requires energy Process where waste is released from a cell Does not require energy Diffusion Endocytosis Mechanism used to move molecules into or out of a cell Required to maintain homeostasis in a cell ATP Exocytosis

Active Transport Requires energy Endocytosis ATP Exocytosis Both Utilizes the semi-permeable membrane and transport proteins Process where waste is released from a cell Mechanism used to move molecules into or out of a cell Required to maintain homeostasis in a cell Passive Transport Osmosis Does not require energy Diffusion

Describe the movement of molecules in the illustration. A)Molecules are moving from a lower concentration to a higher concentration.B)Molecules are moving from a higher concentration to a lower concentration.C)Molecules are moving from a higher concentration to a lower concentration and then from a lower to higher concentration.D)Molecules are moving from a lower concentration to a higher concentration and then from a higher concentration to a lower concentration.

B)Molecules are moving from a higher concentration to a lower concentration.

What is the correct description of the relationship between osmosis and diffusion? A)Diffusion is a type of osmosis that occurs across a cell membrane.B)Osmosis is a type of diffusion that occurs across a cell membrane.C)Osmosis is a type of diffusion that requires energy on the part of the cell, whereas diffusion happens freely.D)Osmosis is not directly related to diffusion. Osmosis involves the movement of liquids. Diffusion involves movement of gases.

B)Osmosis is a type of diffusion that occurs across a cell membrane.

Shaquan placed a potato slice in salt water. After some time he noticed that the slice of potato became limp. Why did this happen to the potato slice? A)The potato was getting old.B)The potato cells lost water to the surroundingsB)The potato cells lost water to the surroundings.C)The potato cells gained water from the surroundings.D)The potato cells had no exchange of materials with the environment.

B)The potato cells lost water to the surroundings

A student performed an experiment with bags of dialysis tubing filled with distilled water to model the process of osmosis. Dialysis tubing is a semi-permeable membrane that allows some materials to passively move through the tubing. The dialysis tubing bags were massed on a balance and then placed in beakers with solutions of sucrose of various concentrations, ranging from 0M to 1.0M sucrose.Select which question the experimental design is best addressing? A)How do hypotonic solutions prevent cells from surviving?B)How do freshwater organisms maintain homeostasis when placed into a hypertonic condition?C)How does the effect of environmental sucrose concentrations impact the movement of water across a membrane?D)How does the temperature in which bags of dialysis tubing are placed directly impact the exchange of materials across the membrane?

C)How does the effect of environmental sucrose concentrations impact the movement of water across a membrane?

A single-celled photosynthetic protist, the euglena, is pictured here. A student has a sample of euglena in a culture. In order to determine the most likely aquatic environment where the euglena lives in nature, the student places samples of euglena in distilled water, 0.5% saltwater, and 5% saltwater. The student measures the activity of the contractile vacuole, an organelle to maintain homeostasis, at the various salinity levels. What are the variables and explain the expected results for this freshwater protist? A)Independent variable:number of contractions of the vacuoleDependent variable:type of solution in which the euglena are placedExpected result: Contractions will be highest in the pure water solution.B)Independent variable:number of contractions of the vacuoleDependent variable: volume of water in which the euglena was placedExpected result: Contractions will be highest in the 5% saltwater solution.C)Independent variable: type of solution in which the euglena are placedDependent variable: number of contractions of the vacuoleExpected result: Contractions will be highest in the pure water solution.D)Independent variable: type of solution in which the euglena are placedDependent variable: number of contractions of the vacuoleExpected result: Contractions will be highest in the 5% saltwater solution.

C)Independent variable: type of solution in which the euglena are placedDependent variable: number of contractions of the vacuoleExpected result: Contractions will be highest in the pure water solution.

Solution A: Egg swells to about twice its original size.Solution B: Egg absorbs bright green color, but remains original size.Solution C: Egg shrivels to about half of its original size.Solution D: Egg remains largely unchanged. A typical egg contains about 2% dissolved solids. Douglas places de-shelled eggs in four unknown solutions provided by his biology teacher. Based on this fact, predict which solution contains 10% saltwater, from the observations of the egg. A)Solution AB)Solution BC)Solution CD)Solution D

C)Solution C

Your lab group is experimenting with the diffusion of molecules across a membrane. Dialysis tubing is used as a model cell membrane because is it semi-permeable, allowing small molecules to cross the membrane, but NOT larger molecules, like starch. A starch solution is placed in the dialysis tubing and then the dialysis tubing is placed in an iodine and water solution. Iodine is used as an indicator for the presence of starch. Normally, iodine is a yellow-brown color (on the left), but in the presence of starch, it turns a deep purple (right). After observing the experimental setup for 20 minutes, the iodine solution remains brown, but the starch solution inside the dialysis tubing is purple and swollen. What CANNOT be concluded from the results? A)Iodine is a small molecule and diffused through the dialysis tubing INTO the starch solution.B)Starch is a large molecule and could NOT diffuse through the dialysis tubing into the iodine solution.C)Starch requires ATP energy for transport and therefore cannot cross the dialysis tubing into the iodine solution.D)The starch solution is hypertonic to the iodine solution, causing water to move across the dialysis tubing INTO the starch solution.

C)Starch requires ATP energy for transport and therefore cannot cross the dialysis tubing into the iodine solution.

The figure shows a classic experiment that demonstrates the principle of osmosis. The left side of the U-tube is filled half-way with 10% red sugar water. Into the tube on the right, distilled water is poured until it is even with the red sugar water. A semi-permeable membrane is placed in the brown area. Predict what will happen in the U-tube after several hours. A)The membrane in the middle will melt away and both sides will mix.B)Both sides will become 5% red sugar water, and will be at equal marks on the U-tube given enough time.C)The left side of the tube will remain red, but rise in volume, as the right side of the tube falls in volume. The distilled water will dilute the sugar water.D)The left side will remain red, but it will fall. The right side will remain clear, but it will rise, as water moves from the 10% sugar water to the distilled water.

C)The left side of the tube will remain red, but rise in volume, as the right side of the tube falls in volume. The distilled water will dilute the sugar water.

Students performed a laboratory experiment to determine the molar concentration of red potatoes. They cut cubes from a whole red potato and massed them. They placed the cubes into various sucrose solutions, whose molar concentrations are shown above. The students then removed the potato cubes from the solutions twenty-four hours later and massed them again. They calculated the percent change for the potatoes in the various solutions. All of the data is displayed above. What is the approximate molar concentration of the red potatoes used in this experiment? A)The red potatoes have approximately a 0.40 M solute concentration because is the treatment with the smallest percent change.B)The red potatoes have approximately a 0.0 M solute concentrations because they have no sucrose component, only starch components.C)The red potatoes have approximately a 0.37 M solute concentration because this is where the potatoes would neither gain nor lose mass.D)The red potatoes have approximately a 1.0 M solute concentration because this is the treatment where the potatoes lost the greatest percentage.

C)The red potatoes have approximately a 0.37 M solute concentration because this is where the potatoes would neither gain nor lose mass.

Your lab group is experimenting with the diffusion of molecules across a membrane. Dialysis tubing is used as a model cell membrane, because is it semi-permeable, allowing small molecules to cross the membrane, but NOT larger molecules, like starch. A starch solution is placed in the dialysis tubing and then the dialysis tubing is placed in an iodine and water solution. Iodine is used as an indicator for the presence of starch. Normally, iodine is a yellow-brown color, but in the presence of starch, it turns a deep purple. After observing the experimental setup for 20 minutes, the iodine solution remains brown, but the starch solution inside the dialysis tubing is purple and swollen. Based on what you learned from the lab, starch is MOST likely to cross the cell membrane at which of the points indicated on the diagram?

D)Starch crosses the cell membrane at E.

Some inquisitive students found two slugs and wanted to take them to science class. The only container they could find was a used potato chip bag. The students stored the slugs in the bag to take to school the next day, When the students opened the bag at school, they found that the slugs had melted and turned to slime. Explain why this happen? A)The slugs had an defensive reaction to the salt, and the slime was a response to that reaction.B)The salt around the slugs created a hypotonic environment, which caused water to diffuse into cells and made them undergo cytolysis.C)The salt around the slugs created a hypertonic environment, which caused water to diffuse out of cells and the cells will shrink.D)The salt around the slugs created an isotonic environment, which caused water to diffuse out of and into the cells which made the slugs melt.

C)The salt around the slugs created a hypertonic environment, which caused water to diffuse out of cells and the cells will shrink.

Solution Egg mass (g) Initial Egg mass (g) after 24 hrs Student Observations Vinegar 45 85 Shell gone; egg seemed swollen and larger 10% Salt water 85 85 No change in egg appearance or size Kayro Syrup 85 31 Egg was wrinkled and shriveled; much smaller Distilled Water 85 105 Egg was larger in size; swollen and tight Students used eggs to observe the effect of osmosis on cells. In the experiment, the egg represented a typical cell. Before beginning the experiment, students soaked the raw eggs overnight in vinegar to remove the shells.After the shells were removed, students obtained the mass of the shell-less eggs. Students then soaked the eggs in a variety of solutions: vinegar, 10% salt water, corn syrup (kayro), and distilled water. After 24 hours, the eggs were removed from their respective solutions, dried off, and massed. The results are recorded in the data table provided. This model shows a plant cell in a solution. Solutions can be hypotonic, hypertonic, or isotonic to the cell. Which one of the solutions tested demonstrates the water movement shown in the model? A)vinegar onlyB)kayro syrup onlyC)distilled water and vinegarD)10% salt water and kayro syrup

C)distilled water and vinegar

The passage states that organisms that live in fresh water cannot survive in salt water. These organisms will undergo a process termed plasmolysis. An organism experiencing plasmolysis would resemble the egg subjected to which variable of the experiment? A)egg in vinegarB)egg in tap waterC)egg in salt waterD)egg in Kayro syrup

D) egg in kayro syrup

A lab group in biology class wanted to model cell transport using wedges of tubers, an underground stem. The students massed the tuber slices, placed them into various sucrose solutions, and then let them soak overnight. The masses of the tuber slices were taken the next day. The data is shown here. What statement is best supported by the data from this experiment? A)As sucrose moved out of the tuber cells, the tubers gained mass.B)The tubers in the 0.6 molar solution lost the most water from their cells.C)The tubers in the 0.8 molar solution gained as much water as those in the 0.4 molar solution.D)As the sucrose concentration decreased, the mass of the tubers increased as water moved into the tuber cells.

D)As the sucrose concentration decreased, the mass of the tubers increased as water moved into the tuber cells.

Students used gummy bears to represent cells in the gummy bear osmosis lab. After obtaining an initial mass for each gummy bear, the gummies were soaked for 24 hours in different solutions and then dried and massed. The solutions included: distilled water, tap water, 20% sugar solution, and 40% salt solution. After 24 hours, the percent change of each gummy bear was calculated and is shown below:Distilled Water: +320%Tap Water: +200%40% Salt Solution: -60%20% Sugar Solution: +85% Based on the data, which gummy bear was in the salt solution and what was the tonicity of that solution? A)A; hypotonicB)D; hypotonicC)B; hypertonicD)C; hypertonic

D)C; hypertonic

The process when molecules tend to move from an area of high concentration to an area of low concentration.

Diffusion

Solution Egg mass (g) Initial Egg mass (g) after 24 hrs Student Observations Vinegar 45 85 Shell gone; egg seemed swollen and larger 10% Salt water 85 85 No change in egg appearance or size Kayro Syrup 85 31 Egg was wrinkled and shriveled; much smaller Distilled Water 85 105 Egg was larger in size; swollen and tight Solution concentration can be described in terms of tonicity. Solutions are hypertonic, isotonic, or hypotonic to cells. A hypotonic solution is one in which the concentration of solutes is greater inside the cell than outside of it. Water will enter the cell via osmosis, to the outside environment. Water moves into the cell and the cell swells. If enough water enters, the cell can burst. An isotonic solution is a balanced solution. That is, the solution concentration is balanced with the solution inside the cell. Finally, when a cell is surrounded by a hypotonic solution, concentration of solute is greater outside the cell..This is one reason why organisms that live in fresh water cannot survive in salt water, the ocean. Water will leave the organism's cells and eventually the cells will undergo plasmolysis and the organisms will die.mIn this lab activity, students performed an experiment using eggs to observe the effect of osmosis on cells. The egg represented a typical cell. Before beginning the experiment, students soaked the raw eggs overnight in vinegar to remove the shells. What they had in hand, then, was actually a raw, shell-less egg.Student Procedure:Day 1 - Students found the mass in grams of their shelled eggs, recoding the mass in the data table. The eggs were placed in a beaker and covered with 200 mL vinegar to remove the shells. Vinegar, a mild acid, reacts with the calcium carbonate in the shell and the shell should disappear.Day 2 - The eggs were removed from the vinegar. Visual observations were recorded. The shell-less eggs were wiped dry, massed, and the mass was recorded in the data table. The eggs were placed in a clean beaker and covered with a 10% salt-water solution.Day 3 - The eggs were removed from the salt water and visual observations were made and recorded. The eggs were wiped dry , massed, and the mass was recorded. The eggs were placed in a clean beaker and covered with sugar (Kayro) syrup.Day 4 - The eggs were removed from the syrup and visual observations were made and recorded. The eggs were carefully wiped with a damp cloth, massed, and the mass was recorded. How do cells maintain water balance through osmosis? Student Response If a salt water fish is placed in a fresh water aquarium, water will leave the fish's cells. In the experiment, the only isotonic solution was the 10% salt water solution. The egg swelled in distilled water because it is hypotonic to the egg's interior. The concentration of solute is greater inside the egg than it is in the Kayro syrup. The egg swells when placed in a hypertonic solution.

In the experiment, the only isotonic solution was the 10% salt water solution. The egg swelled in distilled water because it is hypotonic to the egg's interior.

When the concentration of solute and solvent are equal on both sides of the membrane.

Isotonic

ntroduction: Students performed an experiment using eggs to observe the effect of osmosis on cells. The egg represented a typical cell. Before beginning the experiment, students soaked the raw eggs overnight in vinegar to remove the shells. What they had in hand, then, was actually a raw, shell-less egg.Osmosis is the movement of water from an area of greater to lower concentration through a semi-permeable membrane. Water moves in and out of cells without the cells using any energy.Solution concentration can be described in terms of tonicity. Solutions are hypertonic, isotonic, or hypotonic to cells. A hypertonic is one that has a greater concentration of solute outside the cell and therefore a lower concentration. Water will leave the cell and move to the outside environment. This is one reason organisms that live in fresh water cannot survive in salt water, such as the ocean. Water will leave the organism's cells, the cells will shrivel up and the organisms will die. An isotonic solution is a balanced solution. That is, the solution concentration is balanced with the solution inside the cell. Finally, when a cell is surrounded by a hypotonic solution, the concentration of solute is greater inside the cell and the concentration of water is greater outside. Water moves into the cell and the cell swells. If enough water enters, the cell can burst.Experimental Procedure: Day 1 - Students found the mass in grams of their shelled eggs, recoding the mass in the data table. The eggs were placed in a beaker and covered with 200 mL vinegar to remove the shells.Day 2 - The eggs were removed from the vinegar. Visual observations were recorded. The shell-less eggs were wiped dry, massed, and the mass was recorded in the data table. The eggs were placed in a clean beaker and covered with a 10% salt- water solution.Day 3 - The eggs were removed from the salt water and visual observations were made and recorded. The eggs were wiped dry , massed, and the mass was recorded. The eggs were placed in a clean beaker and covered with sugar (Kayro) syrup.Day 4 - The eggs were removed from the syrup and visual observations were made and recorded. The eggs were carefully wiped with a damp cloth, massed, and the mass was recorded. The eggs were placed in a clean beaker and covered with colored (red, green, or blue) distilled water.Day 5 - The eggs were removed from the water and visual observations were made and recorded. The eggs were dried, massed, and the mass was recorded. Students organized their data and made a bar graph comparing how the solutions affected their egg's (cell's) mass. Data: One student group's data is recorded here. Student Response Mass of egg Make a 10% salt solution Chemical reaction to remove shell Create a hypertonic solution rMeasure amount of liquid used Create an isotonic solution

Mass of egg Balance Balance Make a 10% salt solution Chemical reaction to remove shell Vinegar (acetic acid) Create a hypertonic solution Kayro syrup Measure amount of liquid used Graduated cylinder Create an isotonic solution Salt water solution

Solution Egg mass (g) Initial Egg mass (g) after 24 hrs Student Observations Vinegar 45 85 Shell gone; egg seemed swollen and larger 10% Salt water 85 85 No change in egg appearance or size Kayro Syrup 85 31 Egg was wrinkled and shriveled; much smaller Distilled Water 85 105 Egg was larger in size; swollen and tight Students performed an experiment using eggs to observe the effect of osmosis on cells. The egg represented a typical cell. Before beginning the experiment, students soaked the raw eggs overnight in vinegar to remove the shells. What they had in hand, then, was actually a raw, shell-less egg.Solution concentration can be described in terms of tonicity. Solutions are hypertonic, isotonic, or hypotonic to cells. A hypertonic is one that has a greater concentration of solute outside the cell and therefore a lower concentration. Water will leave the cell and move to the outside environment. This is one reason organisms that live in fresh water cannot survive in salt water, such as the ocean. Water will leave the organism's cells and eventually the cells will undergo plasmolysis and the organisms will die. An isotonic solution is a balanced solution. That is, the solution concentration is balanced with the solution inside the cell. Finally, when a cell is surrounded by a hypotonic solution, concentration of solute is greater inside the cell, concentration of water greater outside. Water moves into the cell and the cell swells. If enough water enters, the cell can burst.Procedure: Day 1 - Students found the mass in grams of their shelled eggs, recoding the mass in the data table. The eggs were placed in a beaker and covered with 200 mL vinegar to remove the shells.Day 2 - The eggs were removed from the vinegar. Visual observations were recorded. The shell-less eggs were wiped dry, massed, and the mass was recorded in the data table. The eggs were placed in a clean beaker and covered with a 10% salt- water solution.Day 3 - The eggs were removed from the salt water and visual observations were made and recorded. The eggs were wiped dry , massed, and the mass was recorded. The eggs were placed in a clean beaker and covered with sugar (Kayro) syrup.Day 4 - The eggs were removed from the syrup and visual observations were made and recorded. The eggs were carefully wiped with a damp cloth, massed, and the mass was recorded. The student data was recorded in the data table. Prior to the start of the experiment, the students hypothesized that both the vinegar and Kayro syrup solutions would be hypertonic to the contents of their eggs. The student data can be seen in the data table above. Does this data confirm their initial hypothesis? Explain. A)Yes. In both instances, the vinegar solution and Kayro syrup, the egg lost mass.B)No. The egg in vinegar was an isotonic situation; the egg in syrup was hypertonic as it lost mass.C)No. The egg in vinegar had an increase in mass therefore vinegar would be hypotonic to the egg's contents.D)No. The egg in Kayro syrup had a decrease in mass therefore syrup would be hypotonic to the egg's contents.

No. The egg in vinegar had an increase in mass therefore vinegar would be hypotonic to the egg's contents.

A non-energy requiring process that moves materials across a cell membrane with the concentration gradient.

Passive transport

To study osmosis, a student placed a thin potato slice in a salt solution. The slice became soft and shriveled. Then, he placed the shriveled slice in water. The slice regained its original shape. Based on the observations, which of these statements is correct? A)The slice regained its shape because salt moved into the potato.B)The potato slice shriveled because water moved from the salt solution into the slice.C)The potato slice shriveled because water moved out of the slice into the salt solution.D)The slice regained its shape because the concentration of salt inside and outside the slice became equal.

The potato slice shriveled because water moved out of the slice into the salt solution.

Process requiring energy for the movement of particles across a cell membrane against the concentration gradient.q

active transport

Our cells are continually moving things in and out. When this happens without the expenditure of cellular energy, with the concentration gradient, we call this passive transport. If the movement of molecules or ions requires a protein channel of some sort, it is called facilitated transport, still requiring no energy.

glucose > O2 > ATP > H2O

When a raw, shell-less egg was placed in sugar solution, the egg shrank. The egg was brought back to its original size by placing it in water. Which process does the experiment demonstrate?

osmosis

Which is an example of passive transport across a cell membrane? A)osmosisB)exocytosisC)endocytosisD)sodium-potassium pump

osmosis

Which process moves water molecules across the membrane of a cell? A)diffusionB)endocytosisC)exocytosisD)osmosis

osmosis

Solution A: Egg swells to about twice its original size.Solution B: Egg absorbs bright green color, but remains original size.Solution C: Egg shrivels to about half of its original size.Solution D: Egg remains largely unchanged. A typical egg contains about 2% dissolved solids. Douglas places de-shelled eggs in four unknown solutions provided by his biology teacher. Based on this fact, predict which solution contains 10% saltwater, from the observations of the egg.

solution c

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

when comparing two solutions, the solution with the lesser concentration of solutes