Transport in CellsCHAPTER 4

Transport of Cells4.1 Diffusion

• The phospholipid membrane’s ability ___________________ ______________________________ the cell is called selective permeable or semipermeability

• This permeability depends on ___________________________________ lipids and proteins– The phospholipid bilayer limits the types of molecules that can through it

• _______________________ can easily pass through• ____________________________ cannot pass through the bilayer

– ___________________ will allow ionic, large, or polar molecules to pass through– There are 3 main ways that molecules can be transport through the

phospholipid membrane• __________ Transport• ___________ Transport • ___________ Transport

4.1 Diffusion• Passive Transport

–The mode of transportation that ___________________ _______________• Three types

– ________________– _________________– _________________

4.1 Diffusion

Diffusion• The movement of molecules from an area of _______________________

_______________________________________________• This difference between concentration of a molecule in two area is

called the __________________• Diffusion results in _________________ or _________________

4.2 Osmosis• A solution is a _________

_______________________________has the same composition throughout

• This mixture can be categorized into two sections– The _________ is the

substance that is being dissolved

– The ___________ is the substance that the solute dissolves in

4.2 Osmosis

• There are 3 different gradients, in terms of solute concentration– If the solute has a ____________________ than the solvent, the

solution is ______________– If the solute has ________________________than the solvent,

the solution is _____________– If the solute and the solvent have ____________________, the

solution is ____________

4.2 Osmosis• Osmosis – the diffusion of ________________________

____________________________from an area of high concentration to an area of low concentration– What happens when a cell is placed in a…?

• Hypertonic Solution• ________________________________________________________• Hypotonic Solution• __________________________________________________________

– Is there a difference between animal cells vs plant cells in this situation?• If so, what is it?• ____________________________________________________________

____________________________________________________________

4.2 OsmosisPlasmolysis – the process by which _____________________ pulls away from the cell wall as it shrivels**ONLY SEEN IN _________ cells**

4.2 Osmosis• Controlling Osmosis

– Osmotic pressure, the main cause for support in plants, is the occurrence that takes place when the cell exerts turgor pressure on the cell wall• This prevents water from being allowed in

– In plants, the central vacuole holds on in water or possibly other nutrients

– In organisms that live in a hypotonic environment, there is a presence of a cellular structure that prevents the taking of too much water• Contractile vacuole – a vacuole that removes excess water from a

cell

• Osmosis

4.3 Facilitated Diffusion• Even though it’s the last form

of diffusion, facilitated diffusion will still follow the trend of Passive Transport

• Facilitated Diffusion– The diffusion of _____________

______________ in the plasma membrane

– There are 3 types of transport proteins• ___________ Protein• ____________Protein• ____________ Protein

4.3 Facilitated Diffusion

• Channel Proteins– Act like a pore in the

membrane that ___ ______________ and small ions through (Ex. – Ion Channel)

• Gated Channel Protein• Transport protein that

opens a “gate_________ _____________________

• Carrier Protein*• Transport protein that

is ____________ _____________, or group of substances

4.3 Facilitated Diffusion

• Ion Channels– Allow the formation of ___________________________ between

the extracellular fluid and the cytosol

4.3 Facilitated Diffusion• Passive Transport

4.4 Active Transport

• With Passive Transport, we were _________________the concentration gradient– In _________Transport, the molecule will be traveling _____________

______________________________________• This process ____________________________ is produced during cellular

respiration– _____

4.4 Active Transport• Active Transport

– The energy-requiring process of pumping molecules and ions across membranes, against a concentration gradient or “uphill”• The _________________________________will be travel across the membrane

through the use of transport proteins• The larger molecule, such as starch, ______________________________ by the

processes called endocytosis and exocytosis– Homeostasis

• ___________________________________________________– Refers to balance or in this case, ________________________________

• There has too be a balance between the Processes of Passive Transport and Active Transport– Active Transport helps to maintain this process

4.5 Sodium-Potassium Pump

• During Active Transport, energy is need to go against the concentration gradient– This energy comes in the form of ______________________

____________• This ATP molecule will supply a ___________________with a

phosphate group causing…– _________________________________________________________

• This will then allow for the molecules or ions already attached ___________________________________________

4.5 Sodium Potassium Pump• Mechanisms of the Sodium-Potassium Pump

– From the cytoplasm, ____________________ions will bind to the carrier protein.

– ATP will donate ____________________, causing the carrier protein to change shape and the three Na+ to be transported out the cell

– Still open to the outside of the cell or extracellular fluid, the carrier protein will have ____________ _____________ bind to it

– This causes the bonded phosphate group to be release

– Finally, _________________________are released inside the cell

4.5 Sodium-Potassium Pump• Electrochemical Gradient

– This transport of ions causes _____________________ ________________________________________

– In order words, there is now the presence of an ___ __________________between the inside the cell and outside the cell

– Specifically, the outside of the membrane is positively charge; while the inside of the membrane is negatively charged

– This ____________________________ is called membrane potential

– This potential will play a huge role in the ______________________________________ and their use of the electrochemical gradient

4.6 Exocytosis & Endocytosis

• Vesicle Transport– A form of active transport that

___________________________ _______________________into or out the cell

– This can occur through two processes• _______________________• _______________________

4.6 Exocytosis & Endocytosis• Endocytosis

– the process of capturing __________ _____________________________by engulfing it with the cell membrane • This engulfing will then create a

vesicles and pinch off– Two types

• ________________________– This is when the membrane engulfs

__________ material (__________________)

• _______________________– This is when the membrane engulfs

______ material (__________________)

4.6 Endocytosis & Exocytosis

• Exocytosis– The process of _____________________________________________________and

releasing their contents to the ____________of the cell• This process also can put _______________________on plasma membrane

Outline of the 3 forms of Transports...

Passive Transport •Works down the concentration gradient◦Uses NO energy◦3 types:◦

Facilitated Diffusion ‣Diffusion, with the help or aide of transport proteins •

Osmosis ‣Diffusion of water •

Water or liquid molecules diffusing ◦Solutions are broken down into Solutes & Solvents •

Solvent- the substance that the solute dissolves in◦Water is the universal substance‣

Solute- the substance that dissolves ◦Hypertonic ‣

More •Hypotonic ‣

•Isotonic ‣

Diffusion ‣Movement of molecules or particles moving from an area of high concentration to •low concentration