Objectives (5 - 10 minutes)

1. Understand the concept of microorganisms: Students should be able to identify and briefly describe what microorganisms are, how they are different from other living beings, and their importance for life on Earth.
2. Understand the role of microorganisms in food production: Students should be able to explain in simple terms how microorganisms are used in the production of foods they consume daily, such as bread, yogurt, and cheese.
3. Recognize the importance of hygiene in food handling: Students should be able to understand the need to maintain hygiene when dealing with food and how it is related to the prevention of diseases caused by microorganisms.

Introduction (10 - 15 minutes)

1. Review of Previous Content: The teacher starts the lesson by reminding students about what living beings are and their basic characteristics. He can use examples of animals, plants, and bacteria to make the explanation more interesting. Additionally, the teacher can ask questions to assess students' prior knowledge on the subject, such as "Do you remember what are the basic needs of all living beings?" and "Can you give examples of living beings you know?".

2. Problem Situations: The teacher presents two problem situations to arouse students' curiosity and introduce the topic of the lesson.

   • First, the teacher can ask students: "Have you ever wondered how the bread we eat every day is made? Why does it rise?".
   • Next, the teacher can propose another question: "And what happens to the milk we leave out of the fridge for a long time? Why does it turn sour?".

3. Contextualization: The teacher explains to students that the answer to these questions is related to microorganisms, very small living beings that we cannot see with the naked eye. He can say that there are microorganisms in the air, water, soil, and even in our bodies. Additionally, the teacher can mention that microorganisms are used in the production of many foods they enjoy, such as bread, yogurt, and cheese.

4. Capturing Students' Attention: To spark students' interest, the teacher can share two curiosities about microorganisms:

   • First, he can mention that there is a type of bacteria called Lactobacillus, which is used in the production of yogurt. These bacteria transform the milk sugar into lactic acid, which gives yogurt its acidic flavor and also helps preserve it for longer.
   • Next, the teacher can explain that yeast, used to make bread and cakes rise, is a type of fungus. This fungus releases carbon dioxide during fermentation, which makes the bread or cake dough full of bubbles and rise.

Development (20 - 25 minutes)

Activity Suggestions:

1. "Discovering Microorganisms" - Group Practical Activity (10 - 15 minutes)

   • Materials:

     • Sheets of paper, markers, and drawing materials (optional)
     • Magnifying glass (optional)
     • Foods containing microorganisms (e.g., bread, fruits, milk)

   • Procedure:

     1. Divide the class into groups of 4 or 5 students and distribute the materials to each group.
     2. Explain that each group will examine a different food to find possible microorganisms.
     3. Ask students to observe the food carefully, using the magnifying glass if necessary, and to draw or describe what they see.
     4. Emphasize that students should keep their hands and work materials clean during the activity to avoid food contamination.
     5. After the observation, discuss with the class what each group found. Remind them that not all microorganisms are visible to the naked eye.
     6. Conclude the activity by highlighting the importance of hygiene in food handling to prevent diseases caused by microorganisms.

2. "Making Homemade Yogurt" - Group Practical Activity (10 - 15 minutes)

   • Materials:

     • Milk, natural yogurt (used as a bacteria "culture"), sugar, and fruits (optional, for flavoring the yogurt)
     • Glass containers with lids (e.g., clean and sterilized dessert pots)
     • Plastic spoons for stirring

   • Procedure:

     1. Divide the class into groups of 4 or 5 students and distribute the materials to each group.
     2. Explain that each group will make homemade yogurt using natural yogurt as a bacteria "culture".
     3. Help students measure the appropriate amount of milk and yogurt for the recipe, and gently mix them in the glass container.
     4. If students wish, they can add a little sugar and fruits to flavor the yogurt.
     5. Close the container tightly with the lid and explain that the yogurt needs to be kept in a warm, dark place for a few hours (at home, students can leave the yogurt in a kitchen cabinet, for example).
     6. Explain that the homemade yogurt will be ready to eat the next day, and if they keep it in the refrigerator, it can last for a few days.

These activities are just suggestions, and the teacher can choose the one that best suits his class. The goal is to engage students actively and practically in learning about microorganisms and their importance in food production. Additionally, these activities help promote cooperation among students, encouraging teamwork and idea discussion.

Return (10 - 15 minutes)

1. Group Discussion (5 - 7 minutes):

   • The teacher should gather all students in a large discussion circle. Each group should have the opportunity to share their findings and experiences during the activities. This includes which microorganisms they observed in the foods and how the process of making homemade yogurt was.
   • During the discussion, the teacher should reinforce the important concepts learned, such as the presence of microorganisms in many foods, the importance of hygiene in food handling, and the role of microorganisms in yogurt production.

2. Connection with Theory (3 - 5 minutes):

   • After the discussion, the teacher should revisit the theoretical concepts covered in the lesson's introduction and connect them with the practical activities carried out. For example, the teacher can explain that students observed bacteria in bread and yogurt, and that these bacteria are microorganisms that play an important role in the production of these foods.
   • The teacher can also reinforce the importance of hygiene in food handling, explaining that students needed to keep their hands and work materials clean during the activities to avoid food contamination by other microorganisms that could cause diseases.

3. Final Reflection (2 - 3 minutes):

   • To conclude the lesson, the teacher should propose that students reflect on what they have learned. He can do this through two simple questions:
     1. "What was the most interesting thing you learned today about microorganisms and food production?"
     2. "Why is hygiene important in food handling?"
   • The teacher should give each student the opportunity to share their answers, thus reinforcing what was learned and encouraging individual expression.

This return is essential to consolidate students' learning, allow them to reflect on what they have learned, and connect theory with practice. Additionally, group discussion and individual reflection promote oral expression and critical thinking, important skills for students' development.

Conclusion (5 - 7 minutes)

1. Summary and Recapitulation (2 - 3 minutes):

   • The teacher should start the conclusion by briefly summarizing the main points covered in the lesson. He can remind students about what microorganisms are, their importance in food production, and the need for hygiene in food handling.
   • Next, the teacher should recap the main discoveries from the practical activities, reinforcing the idea that students directly observed microorganisms in foods and participated in the production process of a food (yogurt) using microorganisms.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes):

   • The teacher should explain that the lesson connected theory, practice, and applications. He can mention that students learned about microorganisms and their importance in food production (theory), observed microorganisms in foods and even produced a food (yogurt) using microorganisms (practice), and understood the importance of hygiene in food handling to prevent diseases caused by microorganisms (applications).

3. Extra Materials (1 minute):

   • The teacher should suggest some extra materials for students who wish to deepen their knowledge on the subject. This may include books, educational websites, videos, or documentaries about microorganisms and food production.
   • For example, the teacher can recommend the book "The Life of Microorganisms" by Luiz Roberto Gaviraghi, the website "MicroWorlds" from the Ministry of Education, or the video "How is Yogurt Made?" from the "Mundo Bita" channel on YouTube.

4. Importance of the Subject (1 - 2 minutes):

   • Finally, the teacher should emphasize the importance of the subject for students' daily lives. He can explain that microorganisms are present in many places, including the foods they consume every day. Additionally, understanding the importance of hygiene in food handling is essential for disease prevention.
   • The teacher can conclude the lesson by saying that from now on, students will be able to look at bread, yogurt, or any other food differently, knowing that behind that food there is a whole "life" of microorganisms playing an important role.

The conclusion is an important step to consolidate students' learning, encourage them to continue exploring the subject, and reflect on the application of the concepts learned in their daily lives. Additionally, by connecting theory, practice, and applications, the teacher helps students understand the relevance of what they have learned.