1. The Processes of the Cell

2. Essential Question: What processes are necessary for the survival of a cell, tissue, organ, and organ system?
Standard:
S7L2a. Explain that cells take in nutrients in order to grow and divide and to make needed materials.

3. Activating Strategy: Watch the time lapse video and answer the questions.
What were your observations?
In order for the changes you observed to occur, what has to happen to the cells in your body?
You may want to speed through some of the video to get to the end. It will not take long for the students to get the point of the video.

4. Your cells are constantly working to perform many activities such as getting food, removing wastes, growing, reproducing, and making new materials.
What do your cells need in order to conduct these necessary activities?
Question students until they can come up with the concept of energy. You may need to ask why they eat to help get to energy.

5. Use the Cell Processes Foldable to take notes as you learn about the many processes cells need to stay alive.

6. To stay alive, cells need a constant supply of energy
To stay alive, cells need a constant supply of energy. Animal cells get energy from food, while plant cells get energy from sunlight.

7. All cells need chemical energy
All cells need chemical energy. Chemical energy is stored in the bonds between the atoms of every molecule.
A major source of chemical energy for most cells is stored in a sugar molecule called glucose.

8. Photosynthesis

9. Plant cells make their own food through the process of photosynthesis.
In this process, plant cells take in light energy and change it into chemical energy in the form of glucose (food). Photosynthesis occurs in the chloroplasts.

10. What do plants need to survive?
Students should be able to already come up with sunlight and water. They may even come up with carbon dioxide. Plants need these substances for Photosynthesis.

11. So, why are plants so important to us?
Photosynthesis Sunlight + Water + Carbon Dioxide = C6H12O6 (Glucose) and Oxygen
So, why are plants so important to us?
Students are not expected to know the reactants and products of photosynthesis. Try to focus on just the overall process and how it will link to cellular respiration and the needs of living organisms.

12. Where do animal cells get their chemical energy?
Let’s Review:
Plant cells make their own food by changing light energy into chemical energy (sugar/glucose) through the process of Photosynthesis which occurs in the Chloroplasts.
Where do animal cells get their chemical energy?

13. Once food is obtained in animal cells and made in plant cells, it must be broken down to release the chemical energy.
This process is called Cellular Respiration. Cellular respiration occurs in the Mitochondria.
Make sure students understand that cellular respiration occurs in both plant and animal cells.

14. Cellular Respiration C6H12O6 (Glucose) + Oxygen = Carbon Dioxide, Water, and Energy (ATP)
Students are not expected to know the reactants and products of cellular respiration.

15. Photosynthesis and Cellular Respiration are the opposite of one another. The input of one process is the output of the other process and vice versa.
Once again reinforce the larger concepts that plants release oxygen as a waste product in photosynthesis which is necessary for cellular respiration and plants take in carbon dioxide which is a waste product from cellular respiration which is necessary for photosynthesis. Therefore, plants and animals are essential to each other.

17. Which is Photosynthesis? Cellular Respiration? How do you know?
Ask students to identify which is Photosynthesis and which is cellular respiration. How do you know?

18. Animations/Video Clips on Photosynthesis and Cellular Respiration
Animation of Cellular Respiration and Photosynthesis:
BrainPop Video on Photosynthesis and Cellular Respiration:
Video animation on Cellular Respiration and Photosynthesis:

19. When learning the functions of cell organelles, we associated the Chloroplasts with solar panels and Mitochondria with Power Generators. With a seat partner, discuss why these analogies fit.

20. Comparing Photosynthesis and Cellular Respiration Venn Diagram
Differentiation: Provide some students/classes with the list of similarities/differences and have other students/classes use their notes to determine the similarities/differences

21. Cellular Respiration in Mitochondria
Tomato Plant
Photosynthesis
In Chloroplasts
Tomatoes eaten
Glucose
Cellular Respiration in Mitochondria
Energy

22. Photosynthesis & Cellular Respiration Storyboard [optional]

23. Distributed Summarizing
Explain why plants and animals are so important to each other for survival?

24. Movement of Material In and Out of the Cell

25. How then do these particles and many others get in and out of cells?
We learned through photosynthesis and cellular respiration that oxygen, carbon dioxide, water, glucose, and energy are constantly used in cells.
How then do these particles and many others get in and out of cells?

26. In our previous unit, we learned that the job of the cell membrane is to allow materials in and out of the cell.

27. The cell membrane is semi-permeable
The cell membrane is semi-permeable. This means that it can let some materials pass through while others can not.

28. Animation of Semi-Permeable

29. Materials must move in and out of a cell in order for it to survive
Materials must move in and out of a cell in order for it to survive. Let’s discuss the different ways in which this occurs.

30. Some materials can move in and out of the cell membrane easily
Some materials can move in and out of the cell membrane easily. Other materials require help or are forced to move in and out of the cell.

31. Natural Movement of Particles Demonstration
Call a small group of students to the front. For this demonstration, tell the students that they are going to need to hold their hands up so their hands are not touching anyone. Take a rope or string and begin circling the students. Keep making the circle smaller so that students have to get closer and closer together. Do this to the point that you notice students are starting to get a little bit uncomfortable, but don’t keep them in this position too long. Then ask some of the students in the group if they are uncomfortable and/or what it would take for them to feel more comfortable. Ask a student sitting down what he/she would expect students to do once the rope is removed. The students should come to the conclusion that the students will move apart. It is natural to move apart and want space. The same is true for particles. Particles naturally move from areas where they are crowded to areas where they are less crowded.

32. Particles naturally want to move from where they are more crowded to where they are less crowded.

33. More Crowded (High Concentration)
Natural Movement of Particles
More Crowded (High Concentration)
Less Crowded (Low Concentration)

34. How does this diagram represent Passive Transport?
The transport (movement) of substances across cell membranes without the use of energy is called Passive Transport.
How does this diagram represent Passive Transport?

35. Why do you think energy is not required for passive transport?
In Passive Transport, substances or particles move from high concentration to low concentration.
Why do you think energy is not required for passive transport?
Tie passive transport back to the natural movement of particles. Since particles naturally want to move from being crowded to less crowded, energy is not required for passive transport because the particles are already moving in the direction in which they would want to travel.

36. Turn to an elbow partner and describe an experience that you could compare to Passive Transport [ex. Easily moving from a crowded area to a less crowded area]

37. There are different types of Passive Transport.
Note: In some cases, facilitated diffusion or diffusion that occurs using protein channels or doorways is called passive transport. Focus on the fact that passive transport does not require energy .

38. Diffusion is a type of passive transport. Why?
Small particles such as oxygen and carbon dioxide move easily across the cell membrane from areas of high concentration to low concentration.
Diffusion is a type of passive transport. Why?
Once again, the particles easily move from high to low concentration which is their natural movement. Therefore, energy is not required so it is a type of passive transport.

39. Diffusion
How is diffusion important for Photosynthesis and Cellular Respiration?
Oxygen and Carbon Dioxide easily diffuse through the cell membrane. Both are necessary for energy production.

40. Everyday Examples of Diffusion
Smell of food, perfume, air freshener, and other substances.

41. Diffusion Animations

42. If the diagram below represents a cell membrane and particles, why are there arrows showing the movement of some of the oval objects?
The ovals are crowded on the left side and are diffusing to the right side where they are less crowded.

43. Distributed Summarizing
Draw a diagram illustrating particles diffusing across a cell membrane.

44. Osmosis is the diffusion of water
Osmosis is the diffusion of water. Water moving from where it is crowded (high concentration) to where it is less crowded (low concentration).

45. Osmosis [Diffusion of Water] Illustration

46. Example of Osmosis
Watering a plant

47. Pure water diffuses more than any other water mixture because it is more crowded (has a higher concentration) than any other water mixtures.

48. The cell bursts and dies.
In this picture a red blood cell is put in a glass of distilled water (pure water with no salt or sugar in it). 
Because there is a higher concentration of water outside the cell, water enters the cell by OSMOSIS.
The cell bursts and dies.

49. Video Clip and Animations on Diffusion/Osmosis

50. Distributed Summarizing: Identify and Share some other examples of Diffusion/Osmosis.

51. Activities on Diffusion/Osmosis [see resources]
Egg-cellent Ideas for Osmosis and Diffusion
Diffusion Lab
Egg Osmosis | Egg Osmosis Demo
Gummy Bear Diffusion/Osmosis
Osmosis Vegetable Lab
The Perfect Taters Mystery

52. Some materials can move in and out of the cell membrane easily
Some materials can move in and out of the cell membrane easily. Other materials require help or are forced to move in and out of the cell.
Diffusion
?????

53. These particles need assistance.
Passive Transport
Some particles are not able to diffuse through the tiny openings in the cell membrane.
These particles need assistance.

54. Passive Transport
Some particles have to go through protein channels or doorways [shown as facilitated diffusion in the diagram to the right].
However, energy is not required and the particles still move from high concentration to low concentration.

55. There are some particles that naturally want to diffuse, but cannot be allowed to diffuse.
Energy must be used to make the particles stay where they are more crowded.

56. Active transport is different from passive transport because it requires energy. Active transport is necessary to make particles move against their natural tendency.
In active transport, particles move from less crowded (low concentration) to more crowded (high concentration).

57. Active transport is important in organs such as the kidneys when harmful particles are made to stay in the organ when they naturally want to diffuse

58. Notice the diagrams show moving from high to low concentrations and low to high. Remind students that ATP means Energy.

60. Animations of Passive and Active Transport

61. If your cell needs a particle and the particle is too big to diffuse through the cell membrane and/or go through a protein channel or doorway, does your cell just go without that particle?

62. Although some particles are too large to go through the cell membrane, they can still get in or out of the cell through the process of Endocytosis and Exocytosis.

63. Endocytosis is the process by which the cell membrane envelops (engulfs) material that is too large to pass through the membrane and then pinches off inside the cell.

64. Endocytosis

65. Exocytosis is the process by which the cell membrane removes material that is too large to pass through the membrane.
The material is surrounded by a membrane within the cell and then expelled by being pushed out of the cell.

66. Exocytosis

68. Animated Cellular Processes: Passive Transport and Active Transport

69. We have discussed all of the ways in which cells live and grow by getting the nutrients they need, but living organisms would not exist over long periods of time if cells did not reproduce.

70. Living organisms can reproduce sexually and/or asexually.

71. Sexual reproduction requires two parents to make an offspring that has characteristics of both parents

72. Organisms that reproduce sexually
Animals
Plants
Fungi

73. Asexual reproduction requires one parent to produce an identical offspring

74. Organisms that reproduce asexually
Bacteria
Plants
Fungi

75. Bacteria reproduces asexually through a process called binary fission

76. Cells reproduce by making more cells or dividing through a process called mitosis (one cell makes two) This is a form of asexual reproduction.

77. Cells make sex cells to help in the reproduction of multi-cellular organisms through a process called meiosis (one makes four)

78. Meiosis This is a form of sexual reproduction

79. Meiosis