Question 1

A membrane transport process is active if it requires __________.

Accepted Answer

Active transport requires energy in the form of ATP to move substances across a membrane, often against their concentration gradient.

Question 2

A solution is said to be isotonic if it contains__________ .

Accepted Answer

An isotonic solution has the same number of nonpenetrating solute particles as the interior of cells, which means there is no net movement of water into or out of the cells, maintaining cell volume and function.

Question 3

Which of the following endocytotic processes is important for moving fluid into cells?

Accepted Answer

Pinocytosis is specifically involved in the uptake of fluids and solutes into cells through the formation of small vesicles.

Question 4

In healthy people, it is good practice to use isotonic solutions for injections into veins of the circulatory system because __________.

Accepted Answer

Isotonic solutions have the same osmotic pressure as the body fluids, which helps maintain the normal volume and function of red blood cells, avoiding the risks of cell shrinkage or bursting that can occur with hypotonic or hypertonic solutions, respectively.

Question 5

The following substances enter cells by receptor- mediated endocytosis.

Accepted Answer

Cholesterol and iron enter cells through receptor-mediated endocytosis, a process where cells absorb metabolites, hormones, proteins – and in this case, cholesterol and iron – by the inward budding of plasma membrane vesicles containing proteins with receptor sites specific to the molecules being absorbed.

Question 6

In this organ, filtration is the important first step in producing urine.

Accepted Answer

The kidney is the organ where filtration occurs as the first step in urine production, removing waste products and excess substances from the blood.

Question 7

Active processes __________.

Accepted Answer

Active processes involve the movement of substances against their concentration or electrical gradients, which requires energy, typically in the form of ATP. This is in contrast to passive processes that rely on existing gradients and do not require cellular energy.

Question 8

Membrane transport may be passive or active. Select the active process from the list below.

Accepted Answer

Phagocytosis is an active process requiring energy (ATP) for a cell to engulf large particles or cells, distinguishing it from passive processes like filtration, osmosis, and simple diffusion that do not require energy.

Question 9

A(n)__________in molecular size and a(n)__________in temperature result in an increased rate of diffusion.

Accepted Answer

A decrease in molecular size allows molecules to move more freely and quickly, while an increase in temperature provides more energy for movement, both of which contribute to an increased rate of diffusion.

Question 10

In comparing simple diffusion to facilitated diffusion, you note that:

Accepted Answer

Both simple and facilitated diffusion require a concentration gradient to move substances from an area of higher concentration to an area of lower concentration. However, only facilitated diffusion requires a specific carrier or protein channel, and neither process requires ATP as they are passive transport mechanisms. Additionally, both processes can only move substances down a concentration gradient, not up.

Question 11

The force that causes water and solutes to cross cell membranes by filtration is ___________ .

Accepted Answer

The force that causes water and solutes to cross cell membranes by filtration is hydrostatic pressure, which is the pressure exerted by a fluid due to its weight. This pressure drives the movement of water and solutes across the membrane, typically from an area of higher pressure to an area of lower pressure, without the need for energy input from ATP.

Question 12

Which statement is true?

Accepted Answer

Active processes require ATP to move substances across cell membranes against a concentration gradient or where specific transport mechanisms are needed, unlike passive processes that rely on the natural movement of substances without the use of cellular energy.

Question 13

Which substance uses a carrier protein to cross the plasma membrane by facilitated diffusion?

Accepted Answer

Glucose molecules are too large and polar to pass through the plasma membrane by simple diffusion, so they require a carrier protein to facilitate their movement across the membrane without the expenditure of energy.

Question 14

Which of the following is true about osmosis?

Accepted Answer

Osmosis is specifically the movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. Solutes do not accompany water in osmosis, and water moves down its concentration gradient, not up.

Question 15

Filtration is not selective. However this property limits movement of some solutes.

Accepted Answer

The size of the membrane pores is a critical factor in filtration that limits the movement of some solutes. If a solute is larger than the pores, it cannot pass through, making the process selective based on size.

Question 16

Which statement about vesicular transport is true?

Accepted Answer

Pinocytosis is a form of endocytosis where the cell ingests extracellular fluids and their dissolved solutes, effectively taking liquids into the cell.

Question 17

A group of cells that are permeable to water are placed in a beaker of hypotonic solution. Will there be a net movement of water across the cell membranes? If so, will it move into or out of the cells?

Accepted Answer

In a hypotonic solution, water moves into the cells due to the higher solute concentration inside the cells compared to the surrounding solution, leading to a net influx of water.

Question 18

These molecules move through the lipid portion of the plasma membrane by simple diffusion.

Accepted Answer

CO2 and O2 are small, nonpolar molecules that can easily pass through the lipid bilayer of the plasma membrane by simple diffusion, unlike ions and larger polar molecules which require specific transport mechanisms.

Question 19

Molecule A has a molecular weight of 175 and Molecule B has a molecular weight of 450. A 0.1 M solution of each is placed on agar gel. Which molecule will diffuse more rapidly through the agar?

Accepted Answer

Molecule A will diffuse more rapidly through the agar because it has a lower molecular weight compared to Molecule B, allowing it to move more easily through the gel matrix.

Question 20

Two important passive processes for membrane transport are ___________ .

Accepted Answer

Diffusion and filtration are passive processes because they do not require energy from the cell to occur. Diffusion involves the movement of molecules from an area of higher concentration to an area of lower concentration, while filtration is the process of separating solids from fluids (liquids or gases) by adding a medium through which only the fluid can pass.

Quiz 5: The Cell: Transport Mechanisms and Cell Permeability

A membrane transport process is active if it requires __________.

A solution is said to be isotonic if it contains__________ .

Which of the following endocytotic processes is important for moving fluid into cells?

In healthy people, it is good practice to use isotonic solutions for injections into veins of the circulatory system because __________.

The following substances enter cells by receptor- mediated endocytosis.

In this organ, filtration is the important first step in producing urine.

Active processes __________.

Membrane transport may be passive or active. Select the active process from the list below.

A(n) in molecular size and a(n) in temperature result in an increased rate of diffusion.

In comparing simple diffusion to facilitated diffusion, you note that:

The force that causes water and solutes to cross cell membranes by filtration is ___________ .

Which statement is true?

Which substance uses a carrier protein to cross the plasma membrane by facilitated diffusion?

Which of the following is true about osmosis?

Filtration is not selective. However this property limits movement of some solutes.

Which statement about vesicular transport is true?

A group of cells that are permeable to water are placed in a beaker of hypotonic solution. Will there be a net movement of water across the cell membranes? If so, will it move into or out of the cells?

These molecules move through the lipid portion of the plasma membrane by simple diffusion.

Molecule A has a molecular weight of 175 and Molecule B has a molecular weight of 450. A 0.1 M solution of each is placed on agar gel. Which molecule will diffuse more rapidly through the agar?

Two important passive processes for membrane transport are ___________ .

Quiz 5: The Cell: Transport Mechanisms and Cell Permeability

A membrane transport process is active if it requires __________.

A solution is said to be isotonic if it contains__________ .

Which of the following endocytotic processes is important for moving fluid into cells?

In healthy people, it is good practice to use isotonic solutions for injections into veins of the circulatory system because __________.

The following substances enter cells by receptor- mediated endocytosis.

In this organ, filtration is the important first step in producing urine.

Active processes __________.

Membrane transport may be passive or active. Select the active process from the list below.

A(n) __________in molecular size and a(n) __________in temperature result in an increased rate of diffusion.

In comparing simple diffusion to facilitated diffusion, you note that:

The force that causes water and solutes to cross cell membranes by filtration is ___________ .

Which statement is true?

Which substance uses a carrier protein to cross the plasma membrane by facilitated diffusion?

Which of the following is true about osmosis?

Filtration is not selective. However this property limits movement of some solutes.

Which statement about vesicular transport is true?

A group of cells that are permeable to water are placed in a beaker of hypotonic solution. Will there be a net movement of water across the cell membranes? If so, will it move into or out of the cells?

These molecules move through the lipid portion of the plasma membrane by simple diffusion.

Molecule A has a molecular weight of 175 and Molecule B has a molecular weight of 450. A 0.1 M solution of each is placed on agar gel. Which molecule will diffuse more rapidly through the agar?

Two important passive processes for membrane transport are ___________ .

A(n) in molecular size and a(n) in temperature result in an increased rate of diffusion.