1 / 39

Cell Transport

Cell Transport. How do things get in and out of cells?. Some things to consider before we start. Molecules in solids, liquids, and gases are always moving. In which state of matter are molecules moving the fastest? Gas Slowest? Solid

phillipt
Download Presentation

Cell Transport

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cell Transport How do things get in and out of cells?

  2. Some things to consider before we start • Molecules in solids, liquids, and gases are always moving. • In which state of matter are molecules moving the fastest? • Gas • Slowest? • Solid • http://www.harcourtschool.com/activity/states_of_matter/

  3. Some things to consider before we start Substances must go through the cell membrane in order to get in or out of a cell.

  4. Some things to consider before we start • What substances need to go IN to a cell? • Water, food/glucose/, oxygen • What substances need to go OUT of a cell? • Wastes, carbon dioxide • Cell Membrane Movie

  5. CELL MEMBRANES • … are selectively permeable, which means that they allow some substances to pass through but not others. • Selective means “choosy” and • Permeable means “to go through”

  6. Cell Transport Video https://app.discoveryeducation.com/search?Ntt=cell+transport

  7. AIM : Cell Transport – Passive Transport Do Now: What would happen if cell membrane was fully permeable to all substances in the cell’s environment?

  8. Diffusion • Molecules will always move from an area where they are more CONCENTRATED to an area where they are less CONCENTRATED. This is called diffusion. What does concentrated mean? • How many particles are packed in an area

  9. D iffusion continues until the molecules of a substance are evenly distributed in an area. • This state of “evenly spread” is called equilibrium. • Do molecules stop moving once equilibrium is reached? • NO http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html http://www.wisc-online.com/objects/index_tj.asp?objid=AP1903

  10. Diffusion by Brainpop

  11. Osmosis • … is a special kind of diffusion that is very important to living things. • Osmosis is the diffusion of water through a selectively permeable membrane. • This is the manner in which water gets into and out of cells. Animation: How Osmosis Works http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

  12. Water molecules will naturally flow from an area in which the water molecules are in greater numbers to an area where they are in fewer numbers. http://www.biologycorner.com/bio1/diffusion.html

  13. Which way are water molecules moving when a plant begins to wilt? • Out of the cells

  14. Passive vs. Active Transport Passive transport • requires no ENERGY from the cell. • Diffusion and osmosis are examples of passive transport. • Molecules in the cell membrane called transport proteins help to move LARGER molecules into or out of the cell. This still does not require energy. Think of this as being like taking a ferry ride without having to pay. This is called Facilitated transport

  15. facilitated transport http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html

  16. AIM : What is Active Transport ? Do Now Predict Outcome – What would happen if the cell was exposed to a drug that disabled the transport proteins in the cell membrane?

  17. Active transport • requires ENERGY and uses transport proteins in the cell membrane. • Used when cells need to move substances from areas of lower concentration to an area of higher concentration. This is the opposite of DIFFUSION and requires energy.

  18. Other types of active transport endocytosis • Endocytosis occurs when VERY LARGE THINGS need to move INTO a cell. • A vesicle fuses to the cell membrane and then releases an object into the cell. • A white blood cell “eating” a BACTERIA would be an example of endocytosis. • What does “endo” mean? “IN”

  19. Exocytosis • Occurs when VERY LARGE molecules need to move OUT of a cell. • A vesicle fuses to the cell membrane and then releases an object out of the cell. • An example of exocytosis is when proteins packaged by the GOLGI BODIES need to move out of the cell, to get to another cell. • What does “exo” mean? OUT OF

  20. Let’s get some practice:Tell if each of the following as diffusion, osmosis, facilitated transport, active transport, endocytosis, or exocytosis. • Large waste molecules stored in vacuoles need to be moved out of a cell: • exocytosis

  21. Water concentration outside a cell is 85%. Water concentration inside the cell is 70%. Water flows into the cell: • Osmosis 70% 85%

  22. You can smell the cookies baking in the oven even before you enter the kitchen: • Diffusion

  23. The concentration of Na ions outside the cell is 10%. The concentration of Na ions inside the cell is 25%. Na ions move into the cell. • Active Transport Na+ Na+ 25% Na+ Na+ Na+ Na+ Na+ Na+ Na+ 10%

  24. A one-celled organism “eats” another one-celled organism: • Endocytosis

  25. Glucose molecules are helped to move into the cell by transport proteins in the cell membrane, but no energy is used to do this: • Facilitated transport

  26. Great Animation http://www.northland.cc.mn.us/biology/Biology1111/animations/transport1.html

  27. Some additional facts about cell transport: Simple Diffusion – only small, nonpolar molecules e.g. Oxygen, Carbon Dioxide, Steroid Hormones. Facilitated diffusion – Ions and polar molecules e.g. sugars, amino acids, water. Uses two types of transport proteins – Channel proteins and carrier proteins.

  28. AIM : What are solutions ? Do Now : Predict what would happen to the concentration of the solution if we will add more of a substance dissolved in it ?

  29. Solution Salt water is considered a solution. How can it be physically separated? • a mixture of two or more substances that is identical throughout • can be physically separated • composed of solutes and solvents the substance in the smallest amount and the one that dissolves in the solvent the substance in the larger amount that dissolves the solute Water (solvent) Iced Tea (solution) Iced Tea Mix (solute) milk, fog, jello are considered solutions

  30. Solutes Change Solvents • The amount of solute in a solution determines how much the physical properties of the solvent are changed • Examples: Lowering the Freezing Point Raising the Boiling Point The freezing point of a liquid solvent decreases when a solute is dissolved in it. Ex. Pure water freezes at 320F (00C), but when salt is dissolved in it, the freezing point is lowered. This is why people use salt to melt ice. The boiling point of a solution is higher than the boiling point of the solvent. Therefore, a solution can remain a liquid at a higher temperature than its pure solvent. Ex. The boiling point of pure water is 2120F (1000C), but when salt is dissolved in it, the boiling point is higher. This is why it takes salt water longer to boil than fresh water.

  31. Concentration • the amount of solute dissolved in a solvent at a given temperature • described as dilute or unsaturated if it has • a low concentration of • solute • described as saturated if it • has a high concentration of • solute • described as supersaturatedif • contains more dissolved solute • than normally possible

  32. Solubility • the amount of solute that dissolves in a certain amount of a solvent at a given temperature and pressure to produce a saturated solution • influenced by: Temperature Pressure Solids increased temperature causes them to be more soluble and vice versa Gases increased temperature causes them to be less soluble and vice versa Ex. Iced Coffee Solids increased pressure has no effect on solubility Gases increased pressure causes them to be more soluble and vice versa Ex. Soda,

  33. AIM : How can we use solubility curves? DO NOW : Explain why it would be possible to dissolve much more NaCl in hot water than in cold water? Because an increase in temperture will increase the solubility of the substance.

  34. Saturated Solubility curve Supersaturated Unsaturated

  35. Solubility curve • Any point on a line represents a saturated solution. • In a saturated solution, the solvent contains the maximum amount of solute. • Example • At 90oC, 40 g of NaCl(s) in 100g H2O(l) represent a saturated solution.

  36. Solubility curve • Any point below a line represents an unsaturated solution. • In an unsaturated solution, the solvent contains less than the maximum amount of solute. • Example • At 90oC, 30 g of NaCl(s) in 100g H2O(l) represent an unsaturated solution. 10 g of NaCl(s) have to be added to make the solution saturated.

  37. Summary : 1. Name a solute and a solvent in following solutions : Sugar Water , Club Soda, Sea Water. 2. A solution that contains less solute than it can hold at a given temperature is said to be ________________ 3. Name two factors that affect solubility.

More Related