e. membranes and transport check your learning

•Take some time to consider the question before moving to the next slide which offers the correct answer.

•Write your answer down before you see the actual answer, this will allow you to test yourself more effectively.

CHECK YOUR LEARNING

Membranes and Transport

Cell Structure

Which of the following is not a function of the cell (plasma) membrane?

A) Carries marker molecules that allow cell-cell recognition.

B) Stores cellular energy in the form of fatty acids and other fats.

C) Defines the cell’s borders.

D) Selects what substances can move in and out of the cell.

Free to share, print, make copies and changes. Get yours at www.boundless.com

Cell Structure

Which of the following are correct regarding diffusion through the lipid bilayer that makes up the plasma membrane?

A) Large particles cannot fit in between the individual phospholipids that are packed together.

B) Only materials that are relatively small and non-polar can go through easily.

C) Polar molecules are repelled by the non-polar lipids that line the inside of the bilayer.

D) All of these answers are correct.

Free to share, print, make copies and changes. Get yours at www.boundless.comOpenStax OER. "The Cell Membrane." CC BY 3.0 http://cnx.org/content/m46021/latest/

Cell Structure

Which of the following are correct regarding diffusion through the lipid bilayer that makes up the plasma membrane?

A) Large particles cannot fit in between the individual phospholipids that are packed together.

B) Only materials that are relatively small and non-polar can go through easily.

C) Polar molecules are repelled by the non-polar lipids that line the inside of the bilayer.

D) All of these answers are correct.

http://www.boundless.com/

http://creativecommons.org/licenses/by/3.0/

http://cnx.org/content/m46021/latest/


Structure and Function of Plasma Membranes

What does the term 'mosaic' refer to in the fluid mosaic model of the plasma membrane?

A) The heterogeneous composition of phospholipids, cholesterol, proteins, and carbohydrates

B) The array of colors seen when the plasma membrane is viewed with a microscope

C) That scientists had to put together pieces from various models to make one to fit

D) The different sizes of plasma membranes that exist in nature

Free to share, print, make copies and changes. Get yours at www.boundless.comBoundless - LO. "Boundless." CC BY-SA 3.0 http://www.boundless.com/


What does the term 'mosaic' refer to in the fluid mosaic model of the plasma membrane?

A) The heterogeneous composition of phospholipids, cholesterol, proteins, and carbohydrates

B) The array of colors seen when the plasma membrane is viewed with a microscope

C) That scientists had to put together pieces from various models to make one to fit

D) The different sizes of plasma membranes that exist in nature


http://creativecommons.org/licenses/by-sa/3.0/




What role does cholesterol play in plasma membrane fluidity?

A) Cholesterol has a detrimental role in membrane fluidity.

B) Cholesterol acts like a magnet pulling proteins around the membrane.

C) Cholesterol forces out the unsaturated fatty acids that 'kink' from the membrane.

D) Cholesterol extends the range of temperature in which the membrane is fluid and functional.



Which of the following statements about passive transport is true?

A) Substances move from areas of high concentration to areas of low concentration.

B) Membrane proteins are always needed in order for it to take place.

C) Substances move from areas of low concentration to areas of high concentration.

D) The input of ATP is required in order to facilitate transportation.



Which of the following substances will NOT diffuse easily across the plasma membrane?

A) Sodium ions

B) Vitamin K

C) Water

D) Oxygen



Which of the following factors does NOT affect the rate of diffusion across a membrane?

A) the temperature of a solution

B) the size of the diffusing particles

C) the number of different types of particles in a solution

D) the concentration gradient across the cell membrane



Which of the following characteristics distinguishes facilitated transport from simple diffusion? Facilitated transport______________.

A) uses membrane proteins and channels to move molecules down concentration gradients.

B) requires the input of cellular energy to transport biomolecules.

C) describes the movement of biomolecules such as proteins, carbohydrates, and fatty acids.

D) explains the movement of molecules or ions from high to low concentration.

Free to share, print, make copies and changes. Get yours at www.boundless.comOpenStax OER. "OpenStax College." CC BY 3.0 http://openstaxcollege.org/


Which of the following characteristics distinguishes facilitated transport from simple diffusion? Facilitated transport ______________.

A) uses membrane proteins and channels to move molecules down concentration gradients.

B) requires the input of cellular energy to transport biomolecules.

C) describes the movement of biomolecules such as proteins, carbohydrates, and fatty acids.

D) explains the movement of molecules or ions from high to low concentration.


http://creativecommons.org/licenses/by/3.0/

http://openstaxcollege.org/



Which of the following statements about channel proteins is true?

A) They do not change shape as they move molecules across a membrane.

B) All of them are open at all times to allow passage of materials.

C) all of these answers

D) Polar compounds pass through them to avoid nonpolar regions of the cell membrane.



In a beaker separated by a membrane permeable only to water, one area has a high solute concentration and the other has a low solute concentration. What do you expect will happen in the beaker?

A) Water will move to the area of low solute concentration.

B) Water will move to the area of high water concentration.

C) Water will move to the area of high solute concentration.

D) The solute will move to the area of low solute concentration.



You take a sample of blood cells and place them in a solution. Fifteen minutes later, you observe that they appear shriveled. What is the tonicity of the solution they were placed in?

A) Hypotonic

B) Isotonic

C) Equitonic

D) Hypertonic



Which of the following is used as a method of osmoregulation in humans?

A) plasmolysis

B) contractile vacuoles

C) albumin

D) turgor pressure



How does active transport move substances against the electrochemical gradient?

A) With the help of ATP, pumps move substances across membranes

B) Sodium and potassium help push substances across membranes.

C) ATP causes red blood cells to break down membranes.

D) all of these answers



Which of the following describes the mechanism of the sodium-potassium pump?

A) Potassium cannot attach to the enzyme until the sodium ions detach from the enzyme.

B) Sodium and potassium ions bind to the enzyme at the same time, and then sodium is released.

C) After ATP is hydrolyzed, the phosphate group attaches to the enzyme before the sodium ions.

D) The process begins when potassium attaches to the enzyme, which then hydrolyzes ATP.



Which of the following applies to secondary active transport and not primary active transport?

A) It only involves moving a molecule up its concentration gradient.

B) It utilizes only antiporter proteins.

C) It always involves moving a molecule into the cell.

D) It does not directly require energy from ATP.



What is the difference between phagocytosis and pinocytosis?

A) Phagocytosis takes in carbohydrates, while pinocytosis takes in lipids.

B) Phagocytosis takes in cations, while pinocytosis takes in anions

C) Phagocytosis takes in caveolin, while pinocytosis takes in clathrin.

D) Phagocytosis takes in large food particles, while pinocytosis takes in liquid particles.


What happens to the membrane of a vesicle after exocytosis?

A) It leaves the cell

B) It is disassembled by the cell

C) It fuses with, and becomes part of the plasma membrane

D) It is used again in another exocytosis event.


In what important way does receptor-mediated endocytosis differ from phagocytosis?

A) It does not involve the pinching off of a membrane

B) It transports only small amounts of fluid

C) It brings in only a specifically targeted substance.

D) It transports only small amounts of fluid


What transport method can bring whole cells into a cell?

A) Receptor mediated endocytosis

B) Phagocytosis

C) Pinocytosis.

D) Facilitated transport

e. membranes and transport check your learning

Education