Question 1

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below.
-Acts as a barrier to water soluble substances.
A)protein
B)carbohydrate
C)lipid bilayer

Accepted Answer

The lipid bilayer is composed of hydrophobic (water-repelling) tails that form the interior of the membrane and hydrophilic (water-attracting) heads that face the inside and outside of the cell. This arrangement creates a barrier to water-soluble substances, preventing them from freely diffusing across the membrane. Proteins and carbohydrates may be involved in other functions of the plasma membrane, but they are not primarily responsible for its barrier properties.

Question 2

Indicate the various roles of the following ions: -cation in greatest concentration in the ECF A)Na⁺ B)K⁺ C)A^- D)Cl^-

Accepted Answer

Na+ is the cation in greatest concentration in the extracellular fluid (ECF), where it plays a crucial role in maintaining the osmotic balance, regulating the body's water content, and supporting nerve and muscle function.

B, C, and D are not the best choices because K+, A-, and Cl- are not the cations in greatest concentration in the ECF. K+ is primarily found inside cells, where it helps to maintain the cell's electrical charge and support enzyme function. A- is an anion, and it is not typically found in high concentrations in the ECF. Cl- is an anion that is found in roughly equal concentrations inside and outside cells, where it helps to maintain the electrical neutrality of cells and support fluid balance.

Question 3

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for Na⁺ at equilibrium potential for Na⁺ A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

The electrical gradient for Na+ at equilibrium potential for Na+ tends to move the ion out of the cell, as like charges repel each other.

Question 4

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -concentration gradient for K⁺ at resting potential A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

The concentration gradient for K⁺ at resting potential suggests that there is a higher concentration of this ion outside the cell compared to inside. Thus, the force working on this ion would push it out of the cell towards the lower concentration region, making the best choice B.

Question 5

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below.
-Forms channels through the membrane.
A)protein
B)carbohydrate
C)lipid bilayer

Accepted Answer

Proteins are responsible for forming channels through the membrane, which allow for the selective transport of molecules across the lipid bilayer. Carbohydrates are typically found on the outer surface of the membrane and play a role in cell recognition and signaling, while the lipid bilayer provides the physical structure of the membrane and serves as a barrier to the free diffusion of most molecules.

Question 6

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -Na⁺-K⁺ pump for K⁺ A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

Na⁺-K⁺ pump moves K⁺ into the cell.

Question 7

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below.
-Serves as membrane-bound enzymes.
A)protein
B)carbohydrate
C)lipid bilayer

Accepted Answer

Proteins are responsible for serving as membrane-bound enzymes, which catalyze various reactions in the cell membrane. They are embedded within the lipid bilayer and perform a variety of functions such as transport of molecules and sensing external signals. Carbohydrates play a role in cell recognition and attachment, while the lipid bilayer provides the structure of the membrane.

Question 8

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -Na⁺-K⁺ pump for Na⁺ A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

The Na+/K+ pump moves 3 Na+ ions out of the cell and 2 K+ ions into the cell. Therefore, this force tends to move Na+ out of the cell, making the correct choice B - Ion tends to be moved out of the cell by this force.

Question 9

Indicate the various roles of the following ions: -anion in greatest concentration in the ECF A)Na⁺ B)K⁺ C)A^- D)Cl^-

Accepted Answer

The anion in greatest concentration in the ECF is chloride ion (Cl-). It is responsible for maintaining the balance of anions and cations in the ECF and plays a vital role in regulating the pH of the blood. Among the given options, only option D contains chloride ions. Therefore, the best choice is option D.

Question 10

Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code:
-If the concentration of substance X outside the cell continues to increase but the rate of substance X's transport into the cell remains constant, what characteristic is being exemplified?
A)specificity
B)saturation
C)competition

Accepted Answer

Saturation refers to the point at which all available transporters for a given substance are in use and increasing the concentration gradient outside the cell does not increase the rate of transport. This scenario indicates that the rate of transport is constant, suggesting that all available transporters are in use and the system is saturated.

Question 11

Indicate the various roles of the following ions: -anion in greatest concentration in the ICF A)Na⁺ B)K⁺ C)A^- D)Cl^-

Accepted Answer

A^- represents negatively charged proteins and organic phosphates, which are the anions in greatest concentration in the intracellular fluid (ICF).

Question 12

Indicate the various roles of the following ions: -cation in greatest concentration in the ICF A)Na⁺ B)K⁺ C)A^- D)Cl^-

Accepted Answer

The cation in greatest concentration in the ICF is potassium (K+). Among the given options, only option B contains potassium (K+) ion in the cationic form. The other ions present in the options (Na+, A+, and Cl-) are typically found in higher concentrations in the extracellular fluid (ECF).

Question 13

Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code:
-If a carrier can handle substance X but not substance Y, what characteristic is being exemplified?
A)specificity
B)saturation
C)competition

Accepted Answer

Specificity refers to the ability of a carrier to recognize and transport a specific substance or group of structurally similar substances while excluding others.

Answer: B
 Saturation refers to the point at which all available carrier molecules are being utilized and transport rate cannot be increased further, even with an increase in substrate concentration.

Answer: C
 Competition refers to the ability of structurally similar substances to compete for the same carrier and transport mechanism, potentially affecting the uptake or distribution of both substances.

Question 14

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for K⁺ at equilibrium potential for K⁺ A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

At the equilibrium potential for K+, the electrical gradient balances the concentration gradient, meaning there is no net movement of K+ ions. However, if considering the electrical gradient alone, it would tend to move K+ ions into the cell, as the inside of the cell is negatively charged relative to the outside.

Question 15

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for K⁺ at resting potential A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

At resting potential, the inside of the cell is negatively charged relative to the outside. The electrical gradient for K+ (potassium ions) tends to move them into the cell because they are positively charged and are attracted to the negative interior.

Question 16

Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code:
-If in the presence of substance Z there is a decreased rate of entry of substance X, what characteristic is being exemplified?
A)specificity
B)saturation
C)competition

Accepted Answer

The presence of substance Z is inhibiting the entry of another substance, X, which indicates that both substances are trying to enter the system through the same transporter. This is an example of competition.

Question 17

Indicate the various roles of the following ions: -ion whose equilibrium potential is greater than the resting membrane potential A)Na⁺ B)K⁺ C)A^- D)Cl^-

Accepted Answer

The answer of Indicate the various roles of the following...

Question 18

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below.
-Is found only on the outer surface of the membrane.
A)protein
B)carbohydrate
C)lipid bilayer

Accepted Answer

Carbohydrate molecules are found only on the outer surface of the membrane in the form of glycoproteins or glycolipids. They are responsible for cell recognition and identification.

Question 19

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -concentration gradient for Na⁺ at resting potential A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

The concentration gradient for Na⁺ at resting potential tends to move the ion into the cell, as the concentration of Na⁺ is higher outside the cell compared to inside.

Question 20

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for Na⁺ at resting potential A)Ion tends to be moved into the cell by this force. B)Ion tends to be moved out of the cell by this force.

Accepted Answer

At resting potential, the inside of the cell is negatively charged compared to the outside. Since Na+ is a positively charged ion, the electrical gradient tends to move Na+ into the cell.

Quiz 3: The Plasma Membrane and Membrane Potential

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. -Acts as a barrier to water soluble substances.

Indicate the various roles of the following ions: -cation in greatest concentration in the ECF

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for Na+ at equilibrium potential for Na+

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -concentration gradient for K+ at resting potential

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. -Forms channels through the membrane.

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -Na+-K+ pump for K+

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. -Serves as membrane-bound enzymes.

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -Na+-K+ pump for Na+

Indicate the various roles of the following ions: -anion in greatest concentration in the ECF

Indicate the various roles of the following ions: -anion in greatest concentration in the ICF

Indicate the various roles of the following ions: -cation in greatest concentration in the ICF

Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code: -If a carrier can handle substance X but not substance Y, what characteristic is being exemplified?

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for K+ at equilibrium potential for K+

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for K+ at resting potential

Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code: -If in the presence of substance Z there is a decreased rate of entry of substance X, what characteristic is being exemplified?

Indicate the various roles of the following ions: -ion whose equilibrium potential is greater than the resting membrane potential

Indicate which constituent of the plasma membrane is responsible for performing the function in question by filling in the appropriate blank using the answer code below. -Is found only on the outer surface of the membrane.

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -concentration gradient for Na+ at resting potential

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for Na+ at resting potential

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for Na⁺ at equilibrium potential for Na⁺

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -concentration gradient for K⁺ at resting potential

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -Na⁺-K⁺ pump for K⁺

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -Na⁺-K⁺ pump for Na⁺

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for K⁺ at equilibrium potential for K⁺

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for K⁺ at resting potential

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -concentration gradient for Na⁺ at resting potential

Indicate whether the force in question tends to move the involved ion in or out of the cell by filling in the blank using the following answer code. -electrical gradient for Na⁺ at resting potential