Membrane Transport Review

Cell Membrane Transport

Structure, Passive, and Active Tranport

Passive Transport

• Passive transport occurs without energy

• Substances move from a high concentration to a low concentration across the membrane.

• There are 3 main examples of passive transport: Simple Diffusion, Facilitated Diffusion, and Osmosis.

Multiple Select

Which of the following are examples of passive transport? (Select all that apply)

• Simple Diffusion

• Osmosis

• Facilitated Diffusion

• Active Transport

Simple Diffusion

• During simple diffusion items move from high concentration to low concentration across the membrane by traveling between the phospholipids

• This can only occur for molecules that are SMALL and UNCHARGED.

• Examples of molecules that move by simple diffusion are: OXYGEN (O₂), and CARBON DIOXIDE (CO₂)

Facilitated Diffusion

• Facilitated diffusion is diffusion that also moves things from a high to a low concentration but with the help from a protein channel.

• Things that move via facilitated diffusion are molecules that are LARGE or CHARGED.

• Examples include: Glucose, Amino Acids, Ions

Multiple Choice

What does a 'region with high concentration' mean?

• An area with a SMALL number of particles

• An area with a LARGE number of particles

• An area with an UNEVEN number of particles

• An area with no particles

Multiple Choice

What is diffusion?

• when molecules move 
• when molecules move from a high concentration to a low.
• no movement 
• molecules move everywhere

Multiple Choice

Simple diffusion is movement of particles from high concentration to low concentration through

• a nucleic acid gateway

• a membrane protein channel

• the phospholipids

• none of the above

Multiple Select

Which type of molecules undergo simple diffusion? (select all that apply)

• Small

• Large

• Charged

• Uncharged

Multiple Choice

Facilitated diffusion is NOT a type of passive transport as it requires energy from the cell.

• True

• False

Multiple Choice

Facilitated Diffusion requires help to move the molecules from

• A nucleic acid gateway

• A protein channel

• The phospholipids

• Cholesterol

Multiple Select

Which type of molecules undergo Facilitated Diffusion?

• Small

• Large

• Charged

• Uncharged

OSMOSIS

• Osmosis is the movement of water from where there is a high concentration of water and low concentration of solute to where there is a low concentration of water and a high concentration of solute.

• Solute remember, is the molecule that is being dissolved into the water. For example, in salt water, the SALT is the SOLUTE.

HYPERTONIC

• When a cell is in a HYPERTONIC environment there is MORE SOLUTE on the OUTSIDE of the cell than on the inside.

• This means there is more water INSIDE the cell and that will mean the water will leave the cell.

• This can cause the cell to lose volume and shrivel up. We call this plasmolysis.

HYPOTONIC

• When a cell is in a HYPOTONIC enviornment there is LESS SOLUTE on the OUTSIDE of the cell than on the inside.

• This means there is more water OUTSIDE the cell and the water will rush into the cell.

• This can cause the cell to gain volume and get bigger or even burst.

• If a cell bursts, we call that lysis.

ISOTONIC

• When a cell is in an ISOTONIC solution, there are equal concentrations of solute on the outside and inside of the cell

• This means the cell is at equilibrium.

• The water will continue to move in both directions evenly.

• This results in no change to the size of the cell and the cell remains normal.

Multiple Choice

In a solution, salt is considered the _______.

• solvent

• solute

• solution

Multiple Choice

In a scenario, salt is placed into a bowl of water.  What is the solvent?

• salt
• water
• saltwater

Multiple Choice

If you looked at red blood cells under a microscope and saw the blood cells exploded, what would you say happened?

• The cells were placed in a hypotonic solution.
• the solution was isotonic.
• The solution was hypertonic.

Multiple Choice

Why can't you drink salt water?

• It's hypertonic to your cells

• It's hypotonic to your cells

• It's isotonic to your cells

• It's paratonic to your cells

Multiple Choice

A blood cell is placed into the jar, as seen. Where will the water go?

• Into the cell

• Out of the cell

• Equally in & out - it's isotonic

• The water is a lie

Multiple Choice

Where will the water go?

• Into the cell

• Out of the cell

• Equally in & out - it's isotonic

• There is no water

Multiple Choice

An animal cell placed in a hypertonic (salty) solution will

• Shrink
• Swell
• Stay the same

Multiple Choice

If there is 5 percent water inside a cell and 5 percent water outside a cell

• more water will move inside the cell

• more water will move outside the cell

• There will be no net movement of water, it moves into and out of the cell at the same time.

Multiple Choice

Osmosis is the movement of _____ across a membrane.

• food

• energy

• oxygen

• water

ACTIVE TRANSPORT

• Sometimes particles need to move from a LOW concentration to a HIGH concentration AGAINST the CONCENTRATION GRADIENT

• This process ALWAYS REQUIRES ENERGY

• There are two types of Active Transport: DIRECT ACTIVE TRANSPORT and BULK ACTIVE TRANSPORT

DIRECT ACTIVE TRANSPORT

• This is when smaller things are brought into the cell from a low concentration to a high concentration.

• Movement of the particles occurs through a membrane protein

• ATP (Cell Energy) is directly used to provide energy for this process.

BULK ACTIVE TRANSPORT

• This is when large items or large amounts of items are moved into or out of the cell. This still occurs from an area of low concentration to an area of high concentration.

• Materials are brought in and out with vacuoles.

• Bringing something in using a vacuole is called ENDOCYTOSIS.

• Pushing something out using a vacuole is called EXOCYTOSIS.

Multiple Choice

What type of transport is this?

• Endocytosis
• Exocytosis
• Diffusion
• Sodium-Potassium Pump

Multiple Choice

What type of transport is this?

• Endocytosis

• Facilitated Diffusion

• Direct Active Transport

• Osmosis

Multiple Choice

Active transport is the movement of large materials across a cell membrane from ______ to ______ concentration

• high to low

• low to high

• high to high

• low to low

Multiple Choice

What is the difference between active and passive transport?

• Active does not need energy and passive uses energy

• Active uses energy and passive does not need energy

• Active stores transport proteins and passive releases

• Active uses hormones and passive does not

Multiple Choice

Which type of transport requires an input of energy?

• Passive Transport
• Osmosis
• Simple Diffusion
• Active Transport

Multiple Choice

What type of transport is this?

• Endocytosis
• Diffusion
• Exocytosis
• Osmosis