Cell Membrane Chapter - Biology 9 - SBHS

January 18' (77) Molecules A and B are commonly found in plant cells. When tested, it was discovered that molecule A quickly passed through the artificial plant cell membrane. Molecule B did not pass through. - State one way the two molecules could differ that would explain in their ability to pass through the artificial plant cell membrane.

(Answer could be written differently) Molecule A is smaller than molecule B, making it able to pass through the cell. B is a larger molecule making it not able to pass through the membrane.

What does hypertonic solution do to the cell?

1. Dehydrates the cell. 2. Water molecules move out of the cell. 3. The cell shrinks. 4. The cell membrane pulls away from the cell wall. {plasmolysis} [plant cells only]

What does hypotonic solution do to the cell?

1. Osmosis occurs, water molecules move into the cell. 2. The cell expands. 3. Then the cell membrane pushes against the cell wall [plant cell only] 4. Making the cells firm again.

What are the types of Passive transport?

1. Simple Diffusion 2. Facilitated Diffusion 3. Osmosis

What size molecule does Active Transport move across the cell membrane?

Active transport moves LARGE molecules from areas of lower concentration to areas of higher concentration.

In the diagram below, in which direction would the net flow of water be the greatest as a result of diffusion? pg. 15 (8)

C to B (higher concentration to a lower concentration)

Create a cell - What's the name of the bag?

Dialysis bag.

Which process accomplishes the movement of gasses illustrated by the arrow in the diagram? (O2 is going into the cell and CO2 is exiting the cell) pg.9 (22)

Diffusion

August 18' (The diagram below represents a container of water divided by a dialysis membrane into areas, X and Y.) Starch solution was added to the water on side X. One hour later, amber-colored starch indicator solution was added to both sides. Identify the colors that could be observed at X and Y after the addition of the starch indicator.

Final color of X: black-blue Final color of Y: amber

August 17' (79) Explain why glucose molecules can cross a cell membrane and starch molecules can not.

Glucose molecules are smaller molecules while Starch molecules are larger, not allowing them to pass through a cell membrane.

Create a cell - What chemical was in the beaker?

Iodine (starch indicator)

Which statement best describes a cell membrane? pg. 15 (4)

It controls the passage of materials into the cell.

What does Active Transport require to carry out this task?

It requires cellular energy {ATP}

January 18' (76) Molecules A and B are commonly found in plant cells. When tested, it was discovered that molecule A quickly passed through the artificial plant cell membrane. Molecule B did not pass through. - The locations of molecules A and B at the begging of the experiment are shown. Which statement best describes what was observed when the setup was examined 20 minutes later?

Only molecule B was found both inside and out of the artificial cell.

Create a cell - What happened to the glucose in the "cell"? Why?

Some of the glucose molecules left the cell because of their small size.

Create a cell - What were the chemicals in the bag?

Starch and Glucose

Create a cell - What does it represent?

The cell membrane.

January 19' (75) Which statement best describes solution C? (diagram represents red blood cells placed in three test tubes, each containing different salt solutions.)

The concentration of dissolved salt in the solution is greater than the concentration in the cells.

Osmosis

The movement of water molecules across a cell membrane.

June 18' (73) (The diagram below represents the major parts of a growing onion plant. Nutrients are represented around the onion.) Which statement best describes how nutrients enter the root cells of the onion plant.?

The nutrients usually move from an area of high concentration in the soil to an area of low concentration in the root cells.

Which diagram best illustrates how the plant cell will appear after being placed in a solution that has a lower water concentration than the cell? pg. (26)

The picture of a cell that has shrunk to a circular shape, away from the cell wall.

January 18' (85) There is a group of plants, known as halophytes, that has traits that enable to survive in salty environments. Describe on change, other than death, that would be observed in the cells of a pant that did not have these traits and was planted in a salty environment.

The plant cells will shrink due to the large intake of salt and the exit of water molecule from the cell. (answers may vary)

Create a cell - What happened to the starch in the "cell"? Why?

The starch in the cell stood inside of the cell because of it's larger molecule size.

June 17' (83) A student added glucose indicator to a beaker to an unknown liquid. Starch indicator was added to a different beaker containing an equal amount of the same unknown liquid. The color of the indicator solutions before they were added to beaker and the color of the contents of the beakers after adding the indicator solutions are recorded in the chart. - State one conclusion the student would make about the unknown liquid based o the results. Support your answer with information from the data table.

The student can conclude that the unknown liquid is a starch based, since the indicator changed the liquid to blue-black after heating in beaker two. (answer wording may vary)

Which statement best describes the behavior of most of these water molecules? pg. 9 (28)

Their overall movement is equal in both directions.

A biologist diluted a blood sample with distilled water. While observing the sample with a microscope, she noted that the red blood cells had burst. This is most likely the result of which process? pg. 9 (25)

This is the result of diffusion.

Active transport

This type of movement uses cellular energy {ATP} to force materials to go across the cell membrane.

Why does passive transport occur across the cell membrane?

To maintain dynamic equilibrium.

August 17' (75) The diagram represents a laboratory experiment involving sucrose and water molecules in a cellophane bag which functions, in the same way as dialysis tubing. - Which statement correctly explains the rise of liquid in the tube at the end of the experiment?

Water entered the bag due to the lower concentration of water inside. The extra water pushed the liquid up the tube as the bag filed.

What is dynamic equilibrium?

When there is an equal amount of molecules on either side of the cell membrane.

August 17' (24) The diagram below represents the results of the net movement of a specific kind of molecule across a living cell membrane. - The movement of molecules from side A to side B is an example of the process of...

active transport.

pg. 10 (34) A high concentration of calcium salts is normally found within the cytoplasm of a certain protozoan, while the surrounding environment contains a lower concentration of the calcium salts. the higher concentration in the protozoan is most probably the result of...

active transport.

pg. 15 (7) The concentration of nitrates is often higher in plant roots than it is in the soil around them. Plants maintain this difference in concentration through...

active transport.

August 18' (16) (A common cycle in biology is represented below) The ATP molecule above is commonly used to...

actively transport molecules in an organism.

January 18' (74) A step in a procedure in the Diffusion Through a Membrane lab is presented in the diagram. - Which procedure is represented in the diagram?

adding salt solution to a specimen under the cover glass.

pg. 16 (11) Which process explains the change in the positions of molecules after five hours? (Diagram of a beaker with a membrane dividing it into halves containing to kinds of molecules)

diffusion.

pg. 10 (33) A cell is placed in distilled water and then transferred to a 5% salt solution. As a result of this procedure, the cell would be likely to...

get larger, then smaller.

Facilitated diffusion

is a form of transport that uses transport proteins to move sugar molecules (or any small molecule) across the cell membrane.

Hypertonic solution

is a strong solution; when water has an extra amount of solutes in it. (salt water)

Simple diffusion

is the movement of oxygen or carbon dioxide across the cell membrane with no energy and no "assistance".

pg. 10 (35) A student prepared a normal wet mount slide of Elodea leaf and observed it with a compound microscope. He then made drawing A from his observation. His second drawing, B, shows his observations of the same cell after it was mounted in a 5% salt solution.The results are most fully explained by...

loss of water from the cell.

Passive Transport -

means when a small molecules move automatically, without energy, from an area of high concentration to an area of low concentration.

January 18' (15) The process of diffusion and active transportation are both used to...

move molecules into or out of the cells of the body.

pg. 10 (32) A cell containing 98% water in its cytoplasm is placed in a 2% salt solution. It should...

neither gain or lose water.

pg. 10 (30)Cytoplasm in the plant cell will shrink if the cell is....

placed in a concentrated salt solution.

pg. 9 (23) In both plant and animal cells, the cell membrane....

regulates diffusion

June 18' (35) One primary function of the cell membrane is...

regulating the flow of simple sugars into or out of the cell.

Create a cell - Diffusion: movement of ____________ molecules from an area of _________ concentration to an area of ______ concentration _________ energy.

small, high, low, without

January 19' (76) Which solution would be most similar in concentration to the normal internal environment of the human circulatory system? (diagram represents red blood cells placed in three test tubes, each containing different salt solutions.)

solution B, only

August 17' (9) A child with cystic fibrosis has an altered protein in his cells that stops chloride ions from leaving the cells. This protein most likely affects the functioning of...

the mitochondria.

pg. 15 (10) One reason a fish that lives in the ocean may have trouble living in s freshwater lake is that...

water concentration in the fish is affected by salt levels in its environment.

pg. 15 (9) The tap water used contained 1% salt and 99% water, while the salt solution contained 6% salt and 94% water. Elodea cells normally contain 1 % salt. Ten minutes after the slides were prepared, a microscope examination of cells in leaves A and B would most likely show evidence that...

water had moved out of the cells of leaf B.

June 18' (76) (A and B below represents two different slide preparations of elodea leaves. Elodea leaves are found in streams and ponds in New York State) The water used on slide A contained 1% slat and 99% water. The salt solution used on slide B contained 6% salt and 94% water. Elodea cell normally contain 1% salt. - Five minutes after the slides were prepared, a student using a compound light microscope to observe the cells in leaves A and B would most likely see that...

water had moved out of the cells of the leaf on slide B.

June 18' (82) A starch solution in a test tube was separated from the water in a beaker by a dialysis membrane. one hour later, it was observed that the liquid had risen in the teat tube. - The rise of the liquid in the test tube that was observed after one hour can be explained as a result of the...

water moving from the beaker into the test tube.

Isotonic

when 2 solutions are the same strength. * Isotonic solutions have the same concentration as the surrounding cells * Does not affect the cell; the cell remains the same.

Hypotonic

when water has low or no solutes of it. (plain water)

pg. 17 (21) Which structure in a cell corresponds with the function of the human lungs?

cell membrane.