2- 3 unit 2 the cell unit 7: topic 7.4 cellular transport · unit 2 the cell – unit 7 the cell...

The Living Environment ’12-‘13 Unit 2 The Cell – Unit 7 The Cell Topic 7.4: Cellular Transport-class key Mr. Murdoch

of 39 Website upload 2014

Unit 7: Topic 7.4 –

Cellular Transport

Name: _________Class key_________

Period: ________________________



Topic 7.4 assignments

Pages/Sections Date Assigned Date Due



Molecules ____move____ from ___high___ to ___low____

Diffusion

__movement__ from HIGH to LOW __concentration__

Topic: Membrane Channels

Objective: Why do molecules move via membrane channels?



Diffusion

Move from HIGH to LOW concentration

__passive__ transport

___no____ energy __needed__

Topic: Diffusion

Objective: Describe the physical process of diffusion.



___Simple___ Diffusion

Move from ____high___ to ____low____

Topic: Simple Diffusion

Objective: Diagram the physical process of simple diffusion.

Which way will fat move?



__Facilitated__ Diffusion

____move____ from HIGH to LOW ___through___ a

___channel___

Topic: Facilitated Diffusion

Objective: Diagram the cellular process of facilitated diffusion.

Which way will sugar move?



Diffusion

___directly___ through ___membrane___

___simple___ diffusion

____no____ energy ___needed___

help ___through___ a protein ___channel___

__facilitated__ diffusion (with ___help___ )

_____no____ energy ___needed___

Topic: Diffusion Differences

Objective: Compare the types of diffusion in cells.



Simple vs. facilitated diffusion

Topic: Diffusion Differences

Objective: Compare the types of diffusion in cells.



Name: ________________ Period: ____________________

Carefully remove this sheet from your packet to hand in.

Work silently and alone to complete this graded exercise.

Check for Understanding

1. Compare simple diffusion to facilitated diffusion.

2. Sketch a diagram showing both simple diffusion and

facilitated diffusion.



Page intentionally blank



Osmosis: Diffusion of Water

The __diffusion__ of ____water___ across a selectively

permeable membrane is called __osmosis__.

Regulating the ___water___ flow ___through___ the plasma

___membrane___ is an important factor in maintaining

homeostasis within a cell.

Most ____cells____ whether in multicellular or unicellular

organisms, are ___subject___ to osmosis because they are

__surrounded__ by ___water___ solutions.

Topic: Osmotic Diffusion

Objective: Compare osmotic diffusion to other diffusion.



___Water___ is very __important__ , so we talk about water

___separately___

Osmosis ≡ ___diffusion___ of ___water___ from ___high____

concentration of water to ___lower____ concentration of

water ___across____ a semi-permeable ___membrane___

Topic: Osmotic Diffusion

Objective: Describe osmotic diffusion and its importance.



What ___controls___ osmosis?

___Unequal___ distribution of ___particles___ , called a

concentration __gradient__ , is one factor that ___controls___

osmosis.

Topic: Osmotic Control

Objective: Describe osmotic control and concentration gradient.



Keeping water balance

Cell __survival__ depends on __balancing__ water

___uptake___ & water ____loss____

Topic: Osmotic Balance

Objective: Describe osmotic balance and its importance.



Cells in an isotonic solution

(__tonicity__ means __concentration__ )

isotonic solution ≡ the __concentration__ of __dissolved__

substances in the __solution__ is the ____same____ as the

__concentration__ of __dissolved__ substances ___inside___

the ___cell___ .

Topic: Isotonicity

Objective: Describe osmotic isotonicity and its importance.



Cells in an isotonic solution

___Water___ molecules move ____into____ and ____out____

of the cell at the ____same____ rate, and cells ___retain___

their normal ___shape___ .

A ___plant____ cell has its ___normal___ shape and pressure

_____in____ an __isotonic__ solution.

Topic: Isotonicity




Keeping right amount of water in cell

___Balanced___ conditions (__isotonic__)

_____no____ __difference__ in concentration of

___water___ between ____cell____ & __environment__

Topic: Isotonicity


That’s

better

!

I could

be better…




cell in __equilibrium__

example: ___blood___

problem: ___None___ : ____water___ flows

____across____ membrane ___equally___ ,

in both directions

___volume___ of cell ___doesn’t___ change

Topic: Isotonicity




Cells in a hypotonic solution:

__Hypotonic__ solution: ___dilute___ solution thus low

____low____ concentration

In a __hypotonic__ solution, ___water___ enters a cell by

osmosis, ___causing___ the cell to ___swell___.

Topic: Hypotonicity

Objective: Describe osmotic hypotonicity and its function.



Cells in a hypotonic solution

___Plant___ cells ___swell____ beyond their normal size as

___pressure___ increases.

(___Plants___ prefer this –it ___makes___ the leaves

____firm____)

Topic: Hypotonicity





__Freshwater__ - ___hypotonic___

a ____cell____ in ___fresh___ water

___high___ concentration of ____water___ around cell

cell ___gains___ water

Topic: Hypotonicity


KABOOM!

No problem

here




example: __Paramecium__

problem: cells ____gain____ water, ____swell____ &

can ___burst___

___water___ continually ____enters____

paramecium cell

solution: __contractile__ vacuole

___pumps___ water ____out____ of cell

Contractile vacuole in Paramecium

Topic: Hypotonicity




Notes page:



Cells in a hypertonic solution

(__tonicity__ means __concentration__ )

__Hypertonic__ solution ≡ __concentrated__ solution, thus a

high ___solute___ concentration

In a __hypertonic__ solution, ___water___ ____leaves____ a

cell by osmosis, causing the cell to ___shrink___

Topic: Hypertonicity

Objective: Describe osmotic hypertonicity and its function.



Cells in a hypertonic solution

___Plant___ cells ____lose____ pressure as the plasma

membrane ___shrinks___ away from the cell wall in a process

called __plasmolysis__






__Saltwater__ - __hypertonic__

a ____cell____ in ____salt____ water

____low____ concentration of ___water___ around cell -

cell ____loses____ water

example: ___shellfish___

problem: cell ___loses___ water

in plants: ___plasmolysis___

in animals: ___shrinking___ cell

solution: ___take___ up ___water___





I’m shrinking,

I’m shrinking!

I will

survive!



Notes page:



Name: ________________ Period: ____________________




1. Why is osmotic diffusion special?

2. Describe isotonicity.

3. Describe hypotonicity.

Cont’d on back



4. Describe hypertonicity.



Passive Transport

When a cell uses _____no_____ ____energy____ to move

__parrticles__ across a membrane ___passive___ transport

occurs

Particles go ___down___ their concentration __gradient__ .

all __diffusion__ & __osmosis__ are __passive__ transport.

Topic: Passive Transport

Objective: Describe the process of passive transport.



Active Transport

___Active___ transport ≡ Movement of materials through a

membrane ___against___ a concentration ___gradinet___ and

___requires___ ____energy___ from the cell.

Topic: Active Transport

Objective: Describe the energy and process of active transport.



Active transport

Cells may need ___molecules___ to move ___against___

concentration “hill”

need to ____pump____ “uphill”

from ____low_____ to ____high____ using

____energy_____

___protein___ pump

____requires____ energy

____ATP____


Objective: Describe the energy and process of active transport.



How ___active____ transport ____occurs____

a ___transport___ protein called a carrier ___protein___ first

____binds____ with a __particle__ of the substance to be

transported.

____Each____ type of ___carrier___ protein has a

____shape____ that fits a ___specific___ molecule or ion.


Objective: Describe how active transport occurs.



Transport of Large Particles

__Endocytosis__ is a ___process___ by which a cell

__surrounds__ and ____takes____ in material from its

environment.

The ___material___ is __engulfed__ and __enclosed__ by a

portion of the cell’s plasma ___membrane___ .

resulting __vacuole__ with its contents ___moves___ to the

____inside___ of the cell

Topic: Endocytosis

Objective: Describe how very large molecules are introduced.

Endocytosis



Transport of Large Particles

__Exocytosis__ is the ___expulsion___ or ___secretion___ of

materials from a cell.

Topic: Exocytosis

Objective: Describe how very large molecules are removed.

Exocytosis



Name: ________________ Period: ____________________




1. Is osmosis passive or active transport? Explain.

2. Where does the energy for active transport come from?

3. Sketch a cell undergoing both endocytosis and exocytosis.



Page intentionally blank



Notes page:

2- 3 unit 2 the cell unit 7: topic 7.4 cellular transport · unit 2 the cell – unit 7 the cell...

Documents