CellMembranePassive ActiveTransport2010.notebook …verderbz.com/files/CellMembranePassiveActive.pdf · CellMembranePassive_ActiveTransport2010.notebook 2 ... What is diffusion? Is

CellMembranePassive_ActiveTransport2010.notebook

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January 18, 2011

Dec 710:47 AM

Aim: How does the cell membrane function to maintain homeostasis?

Homework:

Vocab: Homeostasis, equilibrium, concentration gradient, diffusion, carrier protein, osmosis, hypertonic, hypotonic, isotonic, semi permeable

Read pp. 178183P. 183 # 2, 3, 4

Quiz Friday on Parts of cell & Cell Membrane Function

Do Now: Describe what homeostasis is.

Dec 711:24 AM

Dec 711:24 AM Dec 710:53 AM

Cell Membranes: Gatekeepers of the cell* Substances must be able to move in and out of the cell

A. Passive Transport Def: Substances cross the cell membrane down the concentration gradient; from an area of higher concentration towards an area of lower concentration

Concentration Gradient when one area has a higher concentration gradient than another

Equilibrium when two areas have the same concentration or are filled evenly

1. Simple Diffusion when small molecules can pass directly through the lipid bilayer

2. Facilitated Diffusion molecules that require the assistance of proteins to pass through the lipid bilayer of the cell membrane

a. Channel Proteins create a pore or tunnel through the CM; each tunnel is specific to a certain substance Ex: sugars, amino acids

b. Carrier Protein transports substances that fit at their binding site on one side of cell membrane protein changes shape once the substance binds substance moves across the membrane

Dec 88:52 AM

Four Different Ways for Substances to Move Across a Cell Membrane

Dec 88:47 AM


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January 18, 2011

Dec 88:41 AM

Phospholipid molecules (cutaway view) of Cell Membrane

Jan 38:02 PM

Transport Across Cell MembranesImportanceAll cells acquire the molecules and ions they need from their surrounding extracellular fluid (ECF). There is an unceasing traffic of molecules and ions • in and out of the cell through its plasma/ cell membrane • Examples: glucose, Carbohydrates, Na+ (sodium), Ca2+ (calcium)• In eukaryotic cells, there is also transport in/ out of membranebounded intracellular organelles such as the nucleus, endoplasmic reticulum, Protein, and mitochondria

Two problems to be considered:1. Relative concentrations Molecules and ions move spontaneously down their concentration gradient (i.e., from a region of higher to a region of lower concentration) by diffusion.Molecules and ions can be moved against their concentration gradient, but this process, called active transport, requires the expenditure of energy (usually from ATP).

Jan 38:12 PM

Two problems to be considered:1. Relative concentrations Molecules and ions move spontaneously down their concentration gradient: (i.e., from a region of higher to a region of lower concentration) by diffusion.

Molecules and ions can be moved against their concentration gradient, but this process, called active transport, requires the expenditure of energy (usually from ATP).

Transport across a Membrane

2. Lipid bilayers are impermeable to most essential molecules and ions. The lipid bilayer is permeable to water molecules and a few other small, uncharged, molecules: oxygen (O2) and carbon dioxide (CO2) diffuse freely in and out of the cell.

Osmosis the diffusion of water across a membrane such an important process to the cell that it has a special name

Lipid bilayers are not permeable to: • ions such as: K+, Na+, Ca2+ ,Cl, HCO3

• small hydrophilic molecules like glucose • macromolecules like proteins and RNA

Dec 88:48 AM

Dec 88:51 AM Dec 711:48 AM

Class Notes 12/7/09 LE 5

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January 18, 2011

Jan 38:33 PM

Solving these problems

Mechanisms by which cells solve the problem of transporting ions and small molecules across their membranes

Facilitated diffusion:• Transmembrane proteins create a waterfilled pore through which ions and some small hydrophilic molecules can pass by diffusion. The channels can be opened (or closed) according to the needs of the cell. • Active transport Transmembrane proteins, called transporters, use the energy of ATP to force ions or small molecules through the membrane against their concentration gradient.

Dec 98:24 AM

Aim: What are hypertonic, hypotonic, & isotonic solutions?

Do Now: 1. Explain what a concentration gradient is? 2. What is diffusion? Is energy required?

HomeworkRd pp. 179-183 P. 183 Copy & Answer # 1, Vocabulary: Solvent, Solute,osmosis, extracellular,intracellular, endocytosis, exocytosis, vesicle

1/5/11

Jan 510:15 AM Jan 510:21 AM

Jan 56:51 AM

Osmosis the diffusion of water across a membrane moves passively across a membrane in the direction of high concentration to low concentration.

EXAMPLE: A red blood cell is placed into a dish of distilled water (has NO solutes). What direction will water flow in? Into or out of cell? (Hint: Where is water less concentrated?)

Jan 37:59 PM


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January 18, 2011

Jan 37:59 PM Jan 37:59 PM

Dec 1311:28 PM

Vesicle Mediated Transport (Passive Transport)Vesicles and vacuoles that fuse with the cell membrane may be utilized to release or transport chemicals out of the cell or to allow them to enter a cell.Required due to the size of the molecule- like proteins or bacteria

Exocytosis is the term applied when transport is out of the cell.

Endocytosis is the case when a molecule causes the cell membrane to bulge inward, forming a vesicle, bringing substances into cell

Dec 1311:36 PM

Dec 711:33 AM

Isotonic Solution

A solution that has the same salt concentration as the normal cells of the body and the blood.

When a cell is placed in an isotonic solution, the water diffuses into and out of the cell at the same rate. The fluid that surrounds the body cells is isotonic

LE1 1/6

Dec 711:33 AM

Isotonic Solution



1/6/2011LE3


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January 18, 2011

Dec 711:33 AM

Isotonic Solution



1/6/2011LE3

Dec 711:29 AM

Hypertonic Solution

Hypertonic solution contain a high concentration of solute in relation to the solution within the cell (e.g. the cell's cytoplasm).

When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel up.

LE 3 1/6

Dec 711:29 AM

Hypertonic Solution

Hypertonic solution contain a high concentration of solute in relation to the solution within the cell (e.g. the cell's cytoplasm).

When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel up.

LE1 1/6

Dec 711:30 AM

Hypotonic

A hypotonic solution contain a solution with a lower salt concentration than in normal cells

When a cell is placed in a hypotonic solution, the water diffuses into the cell, causing the cell to swell and possibly explode.

LE3 1/6

Dec 711:30 AM

Hypotonic



LE3 1/6

Dec 711:30 AM

Hypotonic



LE1 1/6


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January 18, 2011

Jan 38:40 PM Dec 711:26 AM

Cell membranes are permeable to water, therefore, the environment the cell is exposed to can have a dramatic effect on the cell.

* A substance must be in solutionin order to Pass through a membrane

Dec 711:26 AM

Cell membranes are permeable to water, therefore, the environment the cell is exposed to can have a dramatic effect on the cell.

Jan 37:53 PM

Jan 68:56 AM

Aim: Reviewing osmosis and diffusion between cells and its environment

Do Now: Begin to work on the review sheet on your desk.

Homework1. Complete review sheet2. Read pp. 1821833. p. 183 #3, 4

QUIZ tomorrow on Cell parts & Diffusion

Jan 37:55 PM


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January 18, 2011

Jan 68:57 AM

Osmosis & Diffusion Review Sheet Name:

Fill in the Blankaway low high hypertonic hypotonicdiffusion molecules osmosis vacuole watersolute permeable towards semipermeable concentration gradient

1. The cell membrane regulates and controls what kind of ** move in & out of the cell.2. When molecules spread from an area of high to low concentration to, it is called **.3. As molecules diffuse, they create a **, which is a difference in concentrations across space.4. Cell membranes are **. This means that they only allow certain things to pass through.5. A membrane that would allow ANYTHING to pass through it would be called **.6. Diffusion is the movement of molecules. Osmosis is the diffusion of **.7. ** is the process of water molecules moving across a cell membrane.8. The direction that water molecules move is determined by the difference in the concentration of ** dissolved in the solvent inside and outside the cell.9. Osmotic pressure, or osmosis, pushes water molecules ** the area of greater solute concentration.10. Water molecules are pulled ** from areas of lower solute concentration.11. The word hypertonic means ** concentration of solutes.12. The word hypotonic means ** concentration of solutes.13. A plant cell undergoes plasmolysis, or shrinking of the cell membrane, when it is placed in a solution with a HIGH concentration of solute. What type of solution causes plasmolysis? **14. An animal cell undergoes cytolysis, or stretching of the cell membrane, when it is placed in a solution with a very LOW concentration of solute. What type of solution causes cytolysis? **15. Turgor pressure is the flow of water into a plant cell that causes the cell membrane to be pushed up against the cell wall and causes the sac in a plant cell to expand. What is this sac that holds this water from the turgor pressure?

**Isotonic Solutions16. ** The concentration of the solutes inside the cell is ______ to the concentration outside the cell.

(A) less than (B) greater than (C) equal to17. ** Water molecules will move:

(A) into the cell faster than out of the cell (B) out of the cell faster than they will move into the cell(C) in and out of the cell at the same rate

18. ** Turgor Pressure is the pressure that water places on the inside of a PLANT cell. An increase in turgor pressure can cause the cell membrane to press up against the cell wall and a decrease in turgor pressure can cause the cell membrane to shrivel. If the turgor pressure is kept constant, the cell membrane will maintain its shape. In an isotonic solution, the turgor pressure is:

(A) normal (B) decreasing (C) increasing

19. ** In animal cells, the cell membrane will:(A) shrivel up (B) be normal (C) expand & possibly burst

20. ** In the picture to the right, the movement of water across the membrane will be(A) mostly out (B) mostly in (C) in and out equally

Hypotonic Solutions21. ** The concentration of the solutes inside the cell is________ to the concentration outside the cell.



23. ** Turgor Pressure is the pressure that water places on the inside of a PLANT cell. An increase in turgor pressure can cause the cell membrane to press up against the cell wall and a decrease in turgor pressure can cause the cell membrane to shrivel. If the turgor pressure is kept constant, the cell membrane will maintain its shape. In a hypotonic solution, the turgor pressure is:

(A) normal (B) decreasing (C) increasing24. ** In animal cells, the cell membrane will:

(A) shrivel up (B) be normal (C) expand & possibly burst25. ** In the picture to the right, the movement of water across the membrane will be

(A) mostly out (B) mostly in (C) in and out equally

Hypertonic Solutions26. ** The concentration of the solutes inside the cell is ________ to the concentration outside the cell.



28. ** Turgor Pressure is the pressure that water places on the inside of a PLANT cell. An increase in turgor pressure can cause the cell membrane to press up against the cell wall and a decrease in turgor pressure can cause the cell membrane to shrivel. If the turgor pressure is kept constant, the cell membrane will maintain its shape. In a hypertonic solution, the turgor pressure is:

(A) normal (B) decreasing (C) increasing

29. ** In animal cells, the cell membrane will:(A) shrivel up (B) be normal (C) expand & possibly burst

30. ** In the picture to the right, the movement of water across the membrane will be(A) mostly out (B) mostly in (C) in and out equally

31. _**_is the process by which an amoeba eats food, while __** __ is the process an amoeba drinks. Both of these are a form of __** ___ transport.

32. When a cell goes against the concentration gradient in order to move material inside this is know as _**__Transport.

33. When a cell uses a ___**__ channel in order to get large molecules across the cell membrane this is known as ___**___ diffusion.

Jan 37:46 PM

Using the terms..........

" This solution is hypertonic as compared to solution 2."

" Blood

Dec 88:46 AM Dec 1111:11 AM

Aim: What is active transport?

Do Now: A red blood cell is 3 different solutions: #1 solution is 3% salt, a second is 10% salt and a third has 0% salt in it. 1. Describe the relationship between them using iso, hyper & hypo tonic vocabulary. 2. Show with arrows the direction of the net flow of water

Dec 1311:21 PM

Active Transport of Sodium ionsThe Gate opens for Na+ (sodium ions) only after the carrier protein channel has energy (Green Glucose/ ATP).

Na+ is moving against the concentration gradient

Dec 1111:14 AM

Active Transport

A. Purpose in order for cell to function correctly

1. Occurs across a cell membrane

2. Goes from low concentration to high concentration this is against concentration gradient

3. Requires energy from the cell (ATP)

4. Uses carrier proteinsEX: Sodium Potassium Pump

Endocytosis a cell uses a vesicle to move material into the cell

Exocytosis cell uses a vesicle to move materials (Ex. wastes, pathogens, proteins) out of the cell


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January 18, 2011

Dec 109:40 AM Dec 1311:13 PM

Active Transport Across the Cell Membrane: Step by Step

Dec 1111:20 AM

Compare & Contrast Passive & Active Transport

CellMembranePassive ActiveTransport2010.notebook …verderbz.com/files/CellMembranePassiveActive.pdf · CellMembranePassive_ActiveTransport2010.notebook 2 ... What is diffusion? Is

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