Passive Cell Transport Lesson 5

Question 1

What is the name of a cell membrane with proteins embedded within it that allow for the transfer of materials across the membrane?

Answer 1

phospholipid bilayer

Question 2

What kind of cell membrane is it where some materials may cross, but others cannot?

Answer 2

semi-permeable

Question 3

A solution contains two main things. What are they?

Answer 3

solute and solvent

Question 4

What is a substance that is being dissolved called? Give an example.

Answer 4

solute - example is salt

Question 5

What is a solvent? Give an example.

Answer 5

A substance that is being dissolved into - example = water

Question 6

How can a concentration of a solution can be increased? Two ways…

Answer 6

1. dissolving more solute

2. removing some of the solvent

Question 7

What is it called when solutions of two different concentrations exist beside each other, possibly separated by a membrane?

Answer 7

concentration gradient

Question 8

Which direction does a solute naturally want to move?

Answer 8

down a concentration gradient from areas of high concentration to low areas of concentration

Question 9

What is the process called when a solute moves down a concentration gradient from an area of high to low concentration?

Answer 9

diffusion

Question 10

When will diffusion stop?

Answer 10

once a state of equilibrium is reached - where both solutions have the same concentration, removing the concentration gradient

Question 11

What is it called when a concentration gradient has a solution with the higher concentration of solute?

Answer 11

hypertonic

Question 12

What is it called when a concentration gradient has a solution with the lower concentration of solute?

Answer 12

hypotonic

Question 13

When solutions have the same concentration, what are they called?

Answer 13

Isotonic solution

Question 14

What is the natural movement of material across a cell membrane NOT requiring energy from the cell?

Answer 14

Passive Transport

Question 15

When does passive transport always occur?

Answer 15

It always occurs DOWN a concentration gradient from areas of HIGH concentration to areas of LOW concentration.

Question 16

What are the three types of passive transport?

Answer 16

1. diffusion
2. osmosis
3. facilitated diffusion

Question 17

What is Diffusion?

Answer 17

A type of passive transport; very small particles can pass DIRECTLY ACROSS the cell membrane from areas of HIGH concentration to areas of LOW concentration

Question 18

What two gases can diffuse directly across the cell membrane WITHOUT requiring the cell to expend energy to intake or remove them?

Answer 18

Oxygen and Carbon Dioxide

Question 19

What is Osmosis?

Answer 19

A type of passive transport; Osmosis is the diffusion of water molecules across a cell membrane.
Water CANNOT cross the phospholipid bilayer of the cell membrane directly, but the cell membrane contains a large number of PORES to allow water in or out of the cell.

Question 20

Typically, if a solute can diffuse across a semi-permeable membrane, why does it do it?

Answer 20

To equalize the concentration gradient

Question 21

If the solute CANNOT cross the membrane (too large, electrically charged, etc) what will the solvent do?

Answer 21

The solvent will cross instead of the solute. This changes the amount of water inside and outside of the cell.

Question 22

When a cell is placed in an extremely hypotonic solution what will the water do?

Answer 22

Water will rush into the cell to try to equalize the concentration of solute. In extreme cases, this intake of water may cause the cell to BURST - cytolysis

Question 23

What is cytolysis?

Answer 23

When the water rushes into the cell to try and equalize the concentration of solute and causes the cell to BURST.

Question 24

What is facilitated diffusion?

Answer 24

a type of passive transport using transport proteins to help substances that are large (like glucose) to diffuse through cell membranes directly; these transport proteins help materials enter and leave the cell

Question 25

What are two types of transport proteins used in facilitated diffusion?

Answer 25

Carrier Proteins

Channel Proteins

Question 26

What is a carrier protein?

Answer 26

Used in facilitated diffusion - a type of passive transport. These proteins allow one particular type of molecule to enter or leave the cell by RECOGNIZING ITS SHAPE.

Question 27

What is a channel protein?

Answer 27

Used in facilitated diffusion - a type of passive transport.

These proteins are PORES in the membrane filled with WATER that can open to allow CHARGED IONS to cross the membrane.