Transport

Transport - Transport - Movement of materials through the cell membrane.

Cells are bathed in a liquid. This makes it easier for materials such as food, oxygen, and water to move into and out of the cell.

Model of the cell membrane

Model of the cell membrane

Transport - Transport - Movement of materials

through the cell membrane.


There are several ways in which materials enter and leave the cell.

•Diffusion

•Osmosis

•Facilitated diffusion

•Active transport


Three types are passive transport, meaning they require no energy.

•Diffusion

•Osmosis


•Active transport


Active transport requires energy to be expended by the cell!

•Diffusion

•Osmosis


•Active transport

Transport - Transport - diffusion

Diffusion

Osmosis

Facilitated diffusion

Active transport

Diffusion is the process by which molecules move from areas of higher concentration to areas of lower concentration.


Diffusion

Osmosis


Active transport

Molecules move from high to low


Diffusion

Osmosis


Active transport

door

Examples


Diffusion

Osmosis


Active transport

Examples

You spray some perfume and 30 seconds later it can be smelled down the hall

Transport - Transport - osmosis

Diffusion

Osmosis


Active transport

Osmosis is the diffusion of water from areas of high

water concentration to areas of low water concentration across a membrane.


Diffusion

Osmosis


Active transport

osmosisosmosis

Watch this animation of water molecules moving across a selectively permeable membrane. Water molecules are the small blue shapes, and the solute is the green.

The solute is more concentrated on the right side to start with, which causes molecules to move across the membrane toward the left until equilibrium is reached.

osmosisosmosis

A membrane that allows some things through is “selectively permeable”, Certain solutes like salt and sugar are too large to fit through the cell membrane.

Water will move in the direction where there is a high concentration of solute (and therefore a lower concentration of water.)

The Rule of the DayThe Rule of the Day

a

No, really. If you sprinkle salt on something, the water appear to be “sucked” from the cells. Actually, the salt lowers the concentration of water, and the water moves from high to low.


Diffusion

Osmosis


Active transport

Osmosis can cause serious problems for a cell. Because the cytoplasm is filled with salts, sugars, protein, and other molecules, there is usually a net movement of water into a cell surrounded by fresh water. This can cause them to over inflate like a balloon!


Diffusion

Osmosis


Active transport An injection of distilled water into the

blood stream can often be fatal. Why?

Transport – Transport – facilitated diffusion

Diffusion

Osmosis


Active transport

•“Carrier proteins” embedded in the cell membrane, help transport materials from one side to another.

•Glucose is a one important substance transported this way

Transport – Transport – facilitated diffusion

Diffusion

Osmosis


Active transport

What is happening at 1, 2, and 3?

Transport – Transport – active transport

Diffusion

Osmosis


Active transport

A cell expends energy to send molecules the wrong way! From areas of low concentration to areas of high concentration.

Transport – Transport – active transport

Diffusion

Osmosis


Active transport

Normally H+ would flow into the cell. ATP (energy) is used to make it flow “backwards”

Transport – Transport – endocytosis

Diffusion

Osmosis


Active transport

Endocytosis: The intake of large particles through the pocketing of the cell membrane and formation of a vacuole

Requires Energy

2 Types of Endocytosis2 Types of Endocytosis(reverse is exocytosis)(reverse is exocytosis)

Pinocytosis

Intake of water through an endocytic vesile.

Phagocytosis

Intake of food through a endocytic vesicle

Lets Play. Lets Play. Name that Form of Name that Form of

Transport!Transport!

#1 A plant is wilting and you #1 A plant is wilting and you water it. The process by which water it. The process by which the water passes through the the water passes through the

plant's cell membranes to plant's cell membranes to enter the cell is…enter the cell is…

A. Diffusion

B. Osmosis

C. Facilitated diffusion

D. Active transport

A plant is wilting and you water A plant is wilting and you water it. The process by which the it. The process by which the

water passes through the water passes through the plant's cell membranes to plant's cell membranes to

enter the cell is…enter the cell is…

A. Diffusion

B. Osmosis


D. Active transport

#2 Which of the following #2 Which of the following require energy?require energy?

A. Diffusion

B. Osmosis


D. Active transport

Which of the following require Which of the following require energy?energy?

A. Diffusion

B. Osmosis


D. Active transport

#3 Would include water only#3 Would include water only

A. Diffusion

B. Osmosis


D. Active transport

Would include water onlyWould include water only

A. Diffusion

B. Osmosis


D. Active transport

#4 The process by which a #4 The process by which a white blood cell engulfs a white blood cell engulfs a

bacterium isbacterium is

A. Diffusion

B. Osmosis


D. Active transport

The process by which white The process by which white blood cell engulfs a bacterium blood cell engulfs a bacterium

isis

A. Diffusion

B. Osmosis


D. Active transport

The process by which a white The process by which a white blood cell engulfs a bacterium blood cell engulfs a bacterium

isis

A. Diffusion

B. Osmosis


D. Active transport

Food coloring is poured in a Food coloring is poured in a glass of water. After 15 glass of water. After 15

minutes it is evenly spread minutes it is evenly spread throughout the glassthroughout the glass

A. Diffusion

B. Osmosis


D. Active transport

Food coloring is poured in a Food coloring is poured in a glass of water. After 15 glass of water. After 15

minutes it is evenly spread minutes it is evenly spread throughout the glassthroughout the glass

A. Diffusion

B. Osmosis


D. Active transport

Student HandoutsStudent Handouts

•Transport problems sheet

•Osmosis lab

Transport Problem Sheet Name____________________________

DI RECTI ONS: read each problem and analyze the sketch representing it. Each problem is worth 3 points. 1 Draw a picture of the problem

2. I ndicate where the concentration by using < and > symbols 3. Place an arrow to show the correct direction of movement of materials. 4. Label each problem, on the line provided, as an example of diff usion, osmosis, or active transport.

1. I n preparing lunch, radishes are salted and placed in a baggie. One experiences limp radishes the next day and notices a defi nite amount of water in the baggie

1. _______________________

2. Blood arrives at the lungs depleted of oxygen that is released to the body’s cells. The blood picks up a new, f resh oxygen supply at the lungs 2. _______________________

3. I n a normal, non-diabetic person, sugar is fi ltered out of the blood into the kidneys. But it is almost EXCLUSIVELY RETURND to the blood from the kidneys using energy. 3._______________________ __

4. Many one-celled animals f ace a survival problem in f resh water. Water is constantly entering the animals. 4. _________________________

Osmosis lab #1 Purpose:

1. To demonstrate the role of the cell membrane in diff usion and osmosis using a dialysis membrane

2. To demonstrate the semipermeability of the cell membrane Procedures:

1. Soak the dialysis membrane in water f or 30 seconds. 2. Gently open the bag twist the end and tie tightly with string. 3. Place approximately 6 droppers f ull of starch solution into the dialysis bag 4. Carefully twist and tie at the other end. 5. Fill your beaker with 100 ml of water and add 6 ml I odine (60 drops). 6. Note the colors in the membrane and in the beaker. 7. Place the bag into the I odine solution in the beaker. 8. Af ter 10 minutes note and record the colors inside and outside of the bag

Data: Table #1 Color Changes

Before Placing bag in I odine

Af ter Placing in I odine

Color of Starch inside cell

Color of I odine and water outside cell

Table #2 Color Change Explanation

Starch Molecules I odine Molecules

Direction of Movement of Materials

Comparison of Pore size in plastic bag to:

Conclusions: 1. 2.

http://ccollege.hccs.cc.tx.us/instru/Biology/AllStudyPages/Diffusion_Osmosis/Elodeagif.swf

Education

Transport