Understanding Proteins: Composition, Functions, and Food Sources Food and Nutrition SS 1 First Term Lesson Notes Week 6

Lesson Plan: Proteins – Composition, Classification, Functions, and Food Sources

Subject: Food and Nutrition
Class: SS1
Term: First Term
Week: 6
Age: 14–16 years
Topic: Proteins
Sub-topic: Composition, Classification, Complementary and Supplementary Values, Functions, Dietary Deficiencies, and Food Sources
Duration: 40 minutes

Behavioral Objectives

By the end of the lesson, students should be able to:

1. Define proteins and explain their composition.
2. Classify proteins into different types.
3. Understand complementary and supplementary values of proteins.
4. Describe the functions of proteins in the body.
5. Identify dietary deficiencies related to proteins.
6. List food sources rich in proteins.

Keywords

• Proteins
• Amino acids
• Essential amino acids
• Non-essential amino acids
• Complete proteins
• Incomplete proteins
• Complementary proteins
• Supplementary proteins
• Deficiency
• Growth
• Tissue repair

Set Induction

The teacher will begin the lesson by asking students about foods they believe are high in protein and what role they think protein plays in their bodies. This engages the students and introduces the topic of proteins.

Entry Behavior

Students have basic knowledge of food groups and some nutrients but might not know much about the specific roles of proteins or the difference between complete and incomplete proteins.

Learning Resources and Materials

• Food charts showing protein-rich foods
• Diagrams of amino acids and protein structure
• Whiteboard and markers
• Printed handouts on protein classification and functions

Building Background / Connection to Prior Knowledge

Students have previously learned about food and nutrition, but this lesson will focus on understanding proteins as a vital nutrient for growth, energy, and repair of body tissues.

Embedded Core Skills

• Analytical skills (understanding protein classifications and their functions)
• Communication skills (explaining protein-related concepts)
• Critical thinking (recognizing complementary and supplementary proteins)

Learning Materials

• Protein composition charts
• Diagrams illustrating complete and incomplete proteins
• Printed examples of protein-rich foods

Reference Books

• Lagos State Scheme of Work
• Food and Nutrition textbooks for secondary schools

Instructional Materials

• Diagrams of amino acid structure
• Protein food charts
• Printed handouts on functions, classifications, and sources of proteins

Content

1. Composition of Proteins:
   • Proteins are made up of amino acids, which are the building blocks of proteins.
   • There are 20 amino acids, 9 of which are essential (cannot be made by the body and must be obtained from food) and 11 are non-essential (the body can make them).
2. Classification of Proteins:
   • Complete Proteins: Contain all nine essential amino acids (found in animal-based foods like meat, eggs, and milk).
   • Incomplete Proteins: Lack one or more of the essential amino acids (found in plant-based foods like beans, peas, and nuts).
   • Complementary Proteins: When two or more incomplete proteins are combined to provide all the essential amino acids (e.g., rice and beans).
   • Supplementary Proteins: One incomplete protein is paired with small amounts of a complementary protein to ensure sufficient amino acids (e.g., eating rice with lentils).
3. Functions of Proteins:
   • Growth and Development: Proteins are essential for growth, especially in children, adolescents, and during pregnancy.
   • Tissue Repair: Proteins help repair damaged tissues, such as muscles and skin.
   • Enzyme Production: Proteins make up enzymes that regulate various biochemical reactions in the body.
   • Immune Function: Proteins play a key role in the production of antibodies that help fight infections.
   • Hormone Production: Certain hormones, like insulin, are made of proteins.
4. Dietary Deficiencies of Protein:
   • Kwashiorkor: A protein deficiency that leads to swelling, stunted growth, and mental impairment.
   • Marasmus: A severe lack of calories and protein, leading to extreme thinness, weakness, and poor development.
   • Fatigue and Weakness: Inadequate protein intake can cause tiredness and weakness due to the lack of tissue repair and energy.
5. Food Sources of Proteins:
   • Animal-based proteins: Meat, poultry, fish, eggs, milk, cheese, and yogurt.
   • Plant-based proteins: Legumes (beans, lentils), nuts, seeds, whole grains, tofu, and soy products.
   • Complementary Proteins: Rice and beans, bread and peanut butter, lentils and chickpeas.

Evaluation Questions (15 Fill-in-the-Blank Questions)

1. Proteins are made up of _______ acids.
   a) Amino
   b) Fatty
   c) Nucleic
   d) Sugar
2. There are _______ essential amino acids in the body.
   a) 5
   b) 9
   c) 12
   d) 20
3. Complete proteins contain all _______ essential amino acids.
   a) 8
   b) 10
   c) 9
   d) 12
4. Incomplete proteins lack one or more of the _______ amino acids.
   a) Essential
   b) Non-essential
   c) Energy
   d) Digestive
5. Proteins help in _______ and development.
   a) Digestion
   b) Growth
   c) Circulation
   d) Respiration
6. The condition caused by protein deficiency that leads to swelling is called _______.
   a) Marasmus
   b) Diabetes
   c) Kwashiorkor
   d) Anemia
7. Kwashiorkor is a disease caused by _______ deficiency.
   a) Fat
   b) Protein
   c) Carbohydrate
   d) Vitamin
8. Which of the following foods is a good source of complete protein?
   a) Beans
   b) Eggs
   c) Rice
   d) Spinach
9. The combination of rice and beans provides _______ protein.
   a) Complete
   b) Incomplete
   c) Supplementary
   d) Complementary
10. A common protein source for vegetarians is _______.
    a) Meat
    b) Fish
    c) Lentils
    d) Butter
11. _______ proteins are found in foods like meat, eggs, and milk.
    a) Incomplete
    b) Complementary
    c) Complete
    d) Supplementary
12. Protein helps in _______ production, such as insulin.
    a) Enzyme
    b) Hormone
    c) Fat
    d) Blood
13. The body uses proteins to repair _______.
    a) Tissues
    b) Muscles
    c) Skin
    d) All of the above
14. A deficiency of protein can lead to _______ and weakness.
    a) Growth
    b) Digestive issues
    c) Fatigue
    d) Muscle building
15. Which of the following is an example of a plant-based protein?
    a) Chicken
    b) Lentils
    c) Fish
    d) Cheese

Class Activity Discussion (15 FAQs with Answers)

1. What are proteins made of?
   Proteins are made of amino acids.
2. Why are essential amino acids important?
   Essential amino acids cannot be made by the body, so we need to get them from food.
3. What is the difference between complete and incomplete proteins?
   Complete proteins contain all the essential amino acids, while incomplete proteins lack one or more.
4. What is complementary protein?
   Complementary proteins are two or more incomplete proteins combined to provide all essential amino acids (e.g., rice and beans).
5. How do proteins aid in tissue repair?
   Proteins help repair damaged tissues like muscles and skin after injury or wear.
6. What are the functions of proteins in the body?
   Proteins help with growth, tissue repair, enzyme production, immune function, and hormone production.
7. What is Kwashiorkor?
   Kwashiorkor is a protein deficiency disease characterized by swelling, stunted growth, and mental impairment.
8. What foods are rich in protein?
   Animal products like meat, eggs, and dairy, and plant-based foods like beans, lentils, and nuts are rich in protein.
9. What happens if we don’t get enough protein?
   A lack of protein can lead to fatigue, weakness, and in severe cases, conditions like Kwashiorkor or Marasmus.
10. What is Marasmus?
    Marasmus is a severe protein and calorie deficiency that leads to extreme weakness and poor growth.
11. What is the difference between supplementary and complementary proteins?
    Supplementary proteins are small amounts of a complementary protein added to an incomplete protein to ensure all essential amino acids.
12. Can vegetarians get enough protein?
    Yes, vegetarians can get enough protein from plant-based sources like beans, lentils, tofu, and soy products.
13. How can we combine foods to get complete proteins?
    By combining foods like rice and beans, or lentils and bread, to ensure all essential amino acids are present.
14. What are the benefits of eating protein-rich foods?
    Protein helps build and repair tissues, make enzymes and hormones, and support immune function.
15. Can too much protein be harmful?
    Excessive protein intake can strain the kidneys and may lead to dehydration or other health issues.

Teacher’s Activities

• Explain the composition, classification, and functions of proteins with visuals.
• Use real-life examples to make the content relatable.
• Lead the class discussion and encourage student participation.
• Monitor and correct any misconceptions during activities.

Learners’ Activities

• Participate in class discussions and share their knowledge of protein sources.
• Complete fill-in-the-blank questions and contribute to the class activity.

Assessment

Students will be assessed through their participation, completion of the fill-in-the-blank questions, and contributions to the class discussion.

Evaluation Questions (10 Questions)

1. What are proteins made of?
2. Name two food sources of complete proteins.
3. Explain the difference between complementary and supplementary proteins.
4. What are the main functions of proteins in the body?
5. What condition is caused by protein deficiency and results in swelling?
6. How can vegetarians ensure they get complete proteins in their diet?
7. What is the role of proteins in growth?
8. Identify two signs of protein deficiency.
9. What are some plant-based sources of protein?
10. Why is protein important for tissue repair?

Conclusion

The teacher summarizes the key points about proteins, emphasizing their role in the body and the importance of consuming adequate protein for health. The teacher reviews student responses and provides additional explanations where necessary.