transport of molecules in a cell
DESCRIPTION
Transport of Molecules in a Cell. Terms to Know. SOLUTE: refers to the substance that is to be dissolved (Salt, Sugar) SOLVENT : responsible for dissolving the solute (Water) SOLUTION : Solvent and solute after combining together ECF : Extracellular Fluid. Surrounds all living cells - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/1.jpg)
Transport of Molecules in a Cell
![Page 2: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/2.jpg)
Terms to Know• SOLUTE: refers to the substance that is to be
dissolved (Salt, Sugar)• SOLVENT: responsible for dissolving the solute
(Water)• SOLUTION: Solvent and solute after combining
together• ECF: Extracellular Fluid. Surrounds all living cells• CONCENTRATION: mass of solute dissolved in the
solvent • SEMI-PERMEABLE (SELECTIVELY-PERMEABLE): a
membrane that allows only some substances in or out
![Page 3: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/3.jpg)
Selectively Permeable Membrane
![Page 4: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/4.jpg)
Transportation of MoleculesActive Transport• Movement of
molecules across a semi-permeable membrane against a concentration gradient with a protein
• ENERGY required
Passive Transport•Movement of molecules across a semi-permeable membrane with the gradient
3 types: Osmosis,Diffusion +
Facilitated Diffusion
•Movement of molecules across a semi-permeable membrane with a protein
•NO ENERGY required
![Page 5: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/5.jpg)
Diffusion• Solute molecules
moving from an area of high concentration to an area of low concentration
• Random motion drives diffusion
• Movement is based on kinetic energy (speed), charge, and mass of molecules
• Equilibrium is reached when there is an even distribution of solute molecules
2
3
14
(water)
![Page 6: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/6.jpg)
High Concentration
Low ConcentrationEquilibrium Reached
![Page 7: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/7.jpg)
Osmosis• Diffusion of water through a semi-permeable membrane
– Permeable to solvents (WATER), but not to large molecules
– High [water] to low [water][concentration]
• Dissolved molecules (i.e. glucose, starch) are called solutes
• REMEMBER:Water = solvent Glucose, Starch, Salt = solutes
![Page 8: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/8.jpg)
Effect of Water on Cells• Hypertonic Environment
– High [solute], low [water]
• Isotonic Environment– [water] = [solute]
• Hypotonic Environment– High [water], low [solute]
![Page 9: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/9.jpg)
OsmosisSucrose will not move but water will
![Page 10: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/10.jpg)
![Page 11: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/11.jpg)
Dialysis Bag Experiment
IodineGlucose
Starch
Dialysis bag
• Dialysis Bag– Semi-permeable
membrane– Water, glucose, & starch
• What passes through the dialysis bag?– Glucose (Benedict’s Test)– Starch (Iodine Solution)
• Time Course Experiment– Every 10 minutes,
measure the amount of glucose & starch present in the beaker
![Page 12: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/12.jpg)
Osmosis in Living Cells
Cellulose in cell wall
Normal plasmolyzed flaccid
turgid
![Page 13: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/13.jpg)
RED BLOOD CELLS
![Page 14: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/14.jpg)
Osmosis in Plant Cells
• Observe Elodea leaves via a wet mount of the sample
10% NaCl
Distilled water
Hypertonic
Hypotonic
Plasmolysis
![Page 15: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/15.jpg)
Recall the Cell Membrane
![Page 16: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/16.jpg)
Proteins in the Plasma (cell) Membrane
![Page 17: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/17.jpg)
Proteins are Specific to certain Solutes
![Page 18: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/18.jpg)
Active Transport
![Page 19: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/19.jpg)
ENDOCYTOSIS
The general term for bringing bulk chemicals into a cell is endocytosis (endo = inside); the general term for bringing bulk chemicals out of a cell is exocytosis (exo=outside).
Moving material into the cell by endocytosis involves the pinching in of a portion of the cell membrane around the material to be transported into the cell. The pinched-in portion eventually breaks free from the cell membrane and forms a vesicle in the cytoplasm.
![Page 20: Transport of Molecules in a Cell](https://reader036.vdocument.in/reader036/viewer/2022062501/56815b62550346895dc94dde/html5/thumbnails/20.jpg)
Homework
• Complete your Cheek Cell & Elodea Cell mini-lab
• Study for your Microscope quiz• Answer questions on p.25 Q.1-19
Next topic: Cell cycle & cell division