Biology Cell Transportation(complete).pptx

Cell Transportation (osmosis, diffusion, etc)

1. Passive and ActiveTransport By Ms. Nelson

2. In completion of this lesson students will: Explain the processes of diffusion and osmosis, after defining both term through watching a video titled “Transport in cells: diffusion and osmosis”. Discuss the importance of diffusion, osmosis and active transport in living systems, after constructing a Venn diagram to show the differences and similarities between transports across cell membrane. Learning Objectives

3. Cells cannot exist in isolation from their surroundings; they need to take in substances and get rid of their waste. Cell membrane surrounding the cytoplasm allowing some substances to enter but keeping others out. This is why the cell membrane is described as being a selectively permeable membranes. “

4. Functions of Cell Membranes Protect cell Control incoming and outgoing substances Maintain ion concentrations of various substances Selectively permeable - allows some molecules in, others are kept out ALL THIS MAINTAINS HOMEOSTASIS (internal balance)

5. Cell Membrane: Phospholipid Bilayer

6. Methods of Transport Across Cell Membranes There are three different methods that allow substances to move in and out of a cell: Diffusion Osmosis Active Transport

7. Transport in Cells

8. Diffusion 01 Types of Passive Transport Osmosis 02

9. Movement of molecules from a place where there is a high concentration to a place where there is low concentration until molecules are evenly distributed Diffusion

10. In a cell, water always moves to reach an equal concentration on both sides of the membrane.

11. Explanation of Diffusion Oxygen is needed by mitochondria for aerobic respiration. The concentration of oxygen within our cells is very low as it is used up all the time. The concentration outside the cell in the tissue fluid is much higher. Molecules of oxygen move about randomly and, over time, more pass through the membrane into the cell than pass out. This movement is diffusion. Unicellular organisms, such as Amoeba, rely on the diffusion of oxygen and carbon dioxide across the cell membrane that forms their body surface. In contrast, large animals have specialized gas exchange surfaces like the alveoli in our lungs. cu

12. Process 1. N o energy needed to move molecules 3. D oes not require semi-permeable membrane to occur 2. Occurs in both gases and liquids

13. Process 4. Occurs faster as temperature increases

14. Importance of Diffusion Our body needs oxygen (cells need oxygen) by means of gaseous exchange surfaces oxygen diffuses into cells. Carbon dioxide are waste the body doesn’t need, by gaseous exchange surfaces, CO2 diffuses out of cells

15. Plants also require CO2, which diffuses into leaves by diffusion Plants produce oxygen as waste gas, which diffuses out of the leaves. Glucose and amino acids produced in digestion are absorbed by diffusion in the ileum

16. Passive Transport: Diffusion Summary Diffusion : random movement of particles from an area of high concentration to an area of low concentration . ( High to Low ) Diffusion continues until all molecules are evenly spaced ( equilibrium is reached)- Note: molecules will still move around but stay spread out. http://bio.winona.edu/berg/Free.htm Simple Diffusion Animation

17. Diffusion

18. Solute  chemical that is present in the greatest amount and, therefore, is the substance in which each of the remaining chemicals are distributed or dissolved e.g. water chemical that present in a lesser amount, relative to the solvent, and must be uniformly-distributed throughout the solution e.g. sugar Solvent Solute vs Solvent

19. Examples of Diffusion in the human body Lungs Oxygen and carbon dioxide enter and leave the lungs Placenta Nutrients and waste materials moving across the placenta in a pregnant mother’s womb. Small intestines Nutrients moving across the small intestines into the blood (Absorption)

20. Movement of water molecules only from a area of high concentration to a area of low concentration across a differentially permeable membrane Osmosis

21. Explanation of Osmosis The diffusion of water through membranes is known as osmosis. The movement of water is influenced by the concentration of the solutions on either side of the membrane. Blood consists of cells suspended in solution of salts, glucose, and proteins called plasma. cu

22. Process 1. N o energy needed to move molecules 3. Requires semi-permeable membrane to occur 2. Occurs faster as temperature increases

23. How Water Molecules Move

24. Importance of osmosis

25. Osmosis : diffusion of water through a selectively permeable membrane Water moves from high to low concentrations Water moves freely through pores. Solute (green) too large to move across. Osmosis animation Passive Transport: Osmosis summary

26. Osmosis

27. Examples of Osmosis in living organisms Plant root Water from the soil entering plant roots Kidneys Water moving across the walls of the nephrons in the kidneys Small intestines Water moving across the small intestines into the blood

28. Scenarios Mary is in the living room and her brother, Mark, hides into her room and sprays her favourite cologne. Without even leaving the living room Mary was able to detect that someone had sprayed her cologne. Explain how this is possible.

29. Tonicity is a relative term Hypotonic Solution - One solution has a lower concentration of solute than another. Hypertonic Solution - one solution has a higher concentration of solute than another. Isotonic Solution - both solutions have same concentrations of solute.

30. Red blood cells in different solutions

31. In A , the liquid becomes cloudy red. If a small drop of this liquid is examined under a microscope the red blood cells have their usual shape (Isotonic Solution) . In B , there is sudden change. The water goes red, but is not cloudy. There are no red blood cells when some of the water is put under a microscope. This is because water has moved by osmosis through the differentially permeable membrane around each red blood cell into the cell. So much water has entered that the volume has increased and burst the membrane (Hypotonic Solution ). In C , water moves out of the cells by osmosis and the cells decrease in volume and become crinkly (Hypertonic Solution) .

32. Osmosis in plant cells Plant cells behave differently to animal cells because they have a cell wall. When plants cells are put into water, they absorb water by osmosis. The vacuole fills with water and pushes against the cell wall making the cell turgid . When placed into a solution with high concentration of solutes, water leaves the cell by osmosis and the vacuole shrinks pulling the cytoplasm and the cell membrane away from the cell wall. This is called plasmolysis . Cells in this state are described as flaccid . Water can move from cell to cell by osmosis when they have cell contents with different concentrations.

33. Plant and Animal Cells put into various solutions

34. Hypotonic Solution Hypotonic : The solution has a lower concentration of solutes and a higher concentration of water than inside the cell . (Low solute; High water) Result : Water moves from the solution to inside the cell): Cell Swells and bursts open ( cytolysis )! Osmosis Animations for isotonic, hypertonic, and hypotonic solutions

35. Hypertonic Solution Hypertonic : The solution has a higher concentration of solutes and a lower concentration of water than inside the cell . (High solute; Low water) Result : Water moves from inside the cell into the solution: Cell shrinks ( Plasmolysis )! Osmosis Animations for isotonic, hypertonic, and hypotonic solutions shrinks

36. Isotonic Solution Isotonic : The concentration of solutes in the solution is equal to the concentration of solutes inside the cell. Result : Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium) Osmosis Animations for isotonic, hypertonic, and hypotonic solutions

37. Movement of particles move through membranes against a concentration gradient. Energy produced through respiration is required to move particles through the membranes from low concentration to high concentration. Active Transport

38. cell membranes have carrier proteins. These carrier proteins span the cell membrane and work to move ions and molecules into or out of the cells by active transport.

39. Explanation of Active transport Active transport occurs in almost all cells, but as we will see it is important in nerve and kidney cells and also the cells that line the villi in the small intestine. Root hair cells absorb mineral ions from the soil by active uptake. cu

40. Process 1. Requires energy release from ATP. 3. Requires semi-permeable membrane to occur 2. Occurs against a concentration gradient

41. Active Transport

42. Active Transport

43. Importance of Active Transport Minerals ions need to move from the soil into plant roots by active transport. Sugars produced by photosynthesis move into the phloem in leaves. Glucose and amino acids produced in digestion are absorbed in the ileum

44. Examples of Active transport in living organisms Cell membrane Sodium and Potassium ions moving across the cell membrane of neurons or muscle cells Plant roots Mineral from soil enters the plant roots. Small intestines Glucose from small intestines enters the blood (Absorption)

45. Activity : Questions Define diffusion. What is moving during osmosis? Which type of cellular transport requires energy is it passive transport or active transport? What are two types of passive transport?

46. Which way does the concentration gradient move? Write the definition of the following terms: Concentration gradient, partially permeable membrane, osmosis, and active transport. Construct a three (3) circle Venn diagram that shows the similarities and differences between diffusion, osmosis, and active transport. Explain why it is important that the concentration of blood plasma does not become too low or too high

47. Describe how active transport occurs to move a molecule out of a cell. Make a spider diagram or a concept map to summaries what you know about movement across cell membranes.

48. Concept Map

49. Experiment 1 Experiment: Diffusion (liquid in liquid) Pour approximately 50ml of water into a beaker. Place one (1) tablespoon of syrup in a cup. Observe and record what occurs immediately as the syrup is placed in the water. Leave undisturbed for 5 minutes and observe again. Each group will present their observations and findings from the experiments. There will be a class discussion surrounding the observations and findings in relation to the process of diffusion.

50. Experiment 2 Lab #: Date: Title: Diffusion (Solid in liquid) Aim: To investigate if Potassium permanganate crystal will diffuse in water.   Apparatus/Reagent/ Materials: Potassium permanganate crystals, distilled water, measuring cylinder/gas jar.   Procedure:  

51. 1. Fill a beaker with 50 mL of water. Leave for several hours to let it become completely still. 2. Drop a small crystal of potassium permanganate into the water. 3. Make a labelled drawing of the beaker to show how the colour is distributed. 4. Leave the beaker completely undisturbed for several hours. 5. Make a second drawing to show how the colour is distributed. Observation: Drawings will go here.

52. Discussion: **Points for discussion** 1. Definition for diffusion 2. Why is it important to leave the water to become completely still before the crystal was put in? 3. Use definition for diffusion to explain your observation. Conclusion:

53. The End Any Questions