Question 1

Diffusion occurs because of random molecular movement.

Accepted Answer

Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration due to random thermal motion. Therefore, diffusion occurs because of random molecular movement.

Question 2

To move a molecule into a cell against the concentration gradient requires energy.

Accepted Answer

Moving a molecule against the concentration gradient requires energy, which is typically provided by the cell in the form of ATP. This process is called active transport.

Question 3

The phospholipid bilayer forms spontaneously in water.

Accepted Answer

The phospholipid bilayer is formed by the self-organization of phospholipid molecules in water due to their hydrophobic and hydrophilic properties. This spontaneous assembly is driven by the energetically favorable interactions between the hydrophobic tails of the phospholipids and the hydrophilic heads with water molecules.

Question 4

Phagocytosis is an example of passive transport.

Accepted Answer

Phagocytosis is an active process in which a cell engulfs and internalizes particles or microorganisms. This requires energy and is therefore an example of active transport, not passive transport.

Question 5

The phospholipid bilayer forms because fatty-acid tails do not dissolve in water.

Accepted Answer

The hydrophobic (water-fearing) fatty-acid tails of the phospholipids cannot dissolve in the hydrophilic (water-loving) environment of the cell membrane. Therefore, the phospholipid molecules arrange themselves to form a bilayer, with the hydrophilic heads facing outward and the hydrophobic tails facing inward, away from the water.

Question 6

Match the following.
A) passive transport
B) facilitated diffusion
C) simple diffusion
D) exocytosis
E) active transport
F) endocytosis
-Uses transport proteins to assist the movement of materials down a concentration gradient

Accepted Answer

The answer of Match the following.
A) passive transport
B) facilitated diffusion
C)...

Question 7

Transport proteins are integral plasma membrane proteins.

Accepted Answer

Transport proteins are a type of integral membrane proteins that facilitate the movement of molecules and ions across the cell membrane.

Question 8

Facilitated diffusion occurs through membrane-bound transport proteins.

Accepted Answer

Facilitated diffusion is the passive movement of molecules across a membrane through specific transport proteins. These proteins help molecules move across the membrane from an area of high concentration to an area of low concentration, without requiring energy input from the cell.

Question 9

Exocytosis is an example of active transport of a substance into the cell.

Accepted Answer

Exocytosis is a process where substances are transported out of the cell, not into it.

Question 10

A cell wall stops a plant cell from taking in so much water that it will burst.

Accepted Answer

The cell wall provides structural support to the plant cell and prevents it from taking in too much water, which could cause it to burst.

Question 11

The functioning of the immune system depends on recognition proteins.

Accepted Answer

Recognition proteins are crucial for the functioning of the immune system. They help identify foreign substances (antigens) and activate immune responses to eliminate them. Without recognition proteins, the immune system would not be able to distinguish between self and non-self and could potentially attack the body's own tissues.

Question 12

Osmosis is an example of passive transport.

Accepted Answer

Osmosis is the diffusion of water molecules across a selectively permeable membrane from a region of high water concentration (low solute concentration) to a region of low water concentration (high solute concentration) without the input of energy. This process occurs spontaneously and is an example of passive transport.

Question 13

Match the following.
A) passive transport
B) facilitated diffusion
C) simple diffusion
D) exocytosis
E) active transport
F) endocytosis
-Movement of materials across a cell membrane that does not require energy

Accepted Answer

The answer of Match the following.
A) passive transport
B) facilitated diffusion
C)...

Question 14

Facilitated diffusion occurs down a concentration gradient.

Accepted Answer

Facilitated diffusion is a passive process where molecules move along the concentration gradient, from an area of high concentration to an area of low concentration, with the help of a membrane protein.

Question 15

Water moves freely through a semipermeable membrane.

Accepted Answer

Water can move freely through a semipermeable membrane, but other substances may be restricted based on their size and charge.

Question 16

Match the following.
A) passive transport
B) facilitated diffusion
C) simple diffusion
D) exocytosis
E) active transport
F) endocytosis
-The movement of molecules down their concentration gradient without the use of a transport protein

Accepted Answer

The answer of Match the following.
A) passive transport
B) facilitated diffusion
C)...

Question 17

Some integral proteins can span the entire phospholipid bilayer.

Accepted Answer

Integral proteins can be transmembrane proteins which span the entire phospholipid bilayer.

Question 18

The most up-to-date explanation of the structure of the plasma membrane is called the fluid-mosaic model.

Accepted Answer

The fluid-mosaic model is the most current explanation for the structure of the plasma membrane. It describes the membrane as a fluid combination of lipids, proteins, and carbohydrates in a mosaic pattern.

Question 19

A substance moving down the concentration gradient is an example of active transport.

Accepted Answer

Active transport refers to the movement of substances against their concentration gradient, requiring energy expenditure by the cell. The movement of a substance down its concentration gradient is passive transport, which does not require energy input from the cell.

Question 20

Active transport moves a substance against the concentration gradient.

Accepted Answer

Active transport requires energy input to move a substance against its concentration gradient, from low to high concentration, which is opposite to the direction of passive transport.

Quiz 5: Lifes Border: the Plasma Membrane

Diffusion occurs because of random molecular movement.

To move a molecule into a cell against the concentration gradient requires energy.

The phospholipid bilayer forms spontaneously in water.

Phagocytosis is an example of passive transport.

The phospholipid bilayer forms because fatty-acid tails do not dissolve in water.

Match the following. A) passive transport B) facilitated diffusion C) simple diffusion D) exocytosis E) active transport F) endocytosis -Uses transport proteins to assist the movement of materials down a concentration gradient

Transport proteins are integral plasma membrane proteins.

Facilitated diffusion occurs through membrane-bound transport proteins.

Exocytosis is an example of active transport of a substance into the cell.

A cell wall stops a plant cell from taking in so much water that it will burst.

The functioning of the immune system depends on recognition proteins.

Osmosis is an example of passive transport.

Match the following. A) passive transport B) facilitated diffusion C) simple diffusion D) exocytosis E) active transport F) endocytosis -Movement of materials across a cell membrane that does not require energy

Facilitated diffusion occurs down a concentration gradient.

Water moves freely through a semipermeable membrane.

Match the following. A) passive transport B) facilitated diffusion C) simple diffusion D) exocytosis E) active transport F) endocytosis -The movement of molecules down their concentration gradient without the use of a transport protein

Some integral proteins can span the entire phospholipid bilayer.

The most up-to-date explanation of the structure of the plasma membrane is called the fluid-mosaic model.

A substance moving down the concentration gradient is an example of active transport.

Active transport moves a substance against the concentration gradient.