Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 1st Term
Week: 6
Age: 15 years
Duration: 45 minutes
Subject: Food and Nutrition
Curriculum Theme: Food and Nutrition
Previous Lesson: Careers in Food and Nutrition.
Topic: Various Food Nutrients e.g. Carbohydrate
Subject Matter: types and chemical structure of carbohydrates, functions of carbohydrates, sources of carbohydrates, digestion and absorption of carbohydrates, metabolism of carbohydrates, dietary deficiency related to carbohydrates

Specific Objectives

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

Cognitive Domain:

Define carbohydrates.
Classify carbohydrates into different types based on their chemical structure.
State the functions of carbohydrates in the body.
List various sources of carbohydrates.
Explain the process of digestion and absorption of carbohydrates.
Identify dietary deficiencies related to carbohydrates.

Affective Domain:

Appreciate the importance of carbohydrates for energy.
Participate actively in discussions about carbohydrate intake.
Value the role of a balanced diet in health.

Psychomotor Domain:

Identify actual food samples that are rich in carbohydrates.
Arrange different food items according to their nutrient groups.

Discuss with peers the impact of carbohydrate deficiency.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Food and Nutrition.
State Unified Scheme of Work for Senior Secondary School.
Food and Nutrition for Senior Secondary Schools by L. A. Adenuga.

Instructional Materials

The teacher will teach this lesson with the aid of:

A chart of food items and nutrients.
Samples of carbohydrate foods (e.g., yam, rice, garri, bread, sugar).
A digestion diagram chart illustrating the digestive system.

Rationale for the Lesson

Understanding carbohydrates helps pupils make informed choices about their diet. This knowledge enables them to maintain good health and prevent diet-related health problems that may arise from inadequate or excessive consumption of carbohydrates.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of food and nutrition, including the general concept of food groups and nutrients.

Lesson Content/Board Summary

Carbohydrates

Definition of Carbohydrates

Carbohydrates are organic compounds made up of carbon, hydrogen, and oxygen. They are the body’s primary source of energy.

Types and Chemical Structure of Carbohydrates

Carbohydrates are classified based on their sugar units:

Monosaccharides: Simple sugars that cannot be broken down further. Examples include glucose, fructose, and galactose.
Disaccharides: Formed when two monosaccharides combine. Examples include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).
Polysaccharides: Complex carbohydrates made up of many monosaccharide units. Examples include starch, glycogen, and cellulose (fibre).

Functions of Carbohydrates

The following are the main functions of carbohydrates in the body:

Provide energy for body activities and metabolic processes.
Spare protein for body-building and repair.
Help in the metabolism of fats, preventing ketosis.
Provide dietary fibre (cellulose) which aids digestion and prevents constipation.

Sources of Carbohydrates

Common sources of carbohydrates include:

Starchy foods: Yam, cassava, rice, maize, potatoes, plantain, bread, pasta.
Sugary foods: Sugar, honey, fruits (e.g., mango, banana), soft drinks, sweets.
Legumes: Beans, peas (contain some carbohydrates).

Digestion and Absorption of Carbohydrates

The digestion of carbohydrates begins in the mouth with salivary amylase. It continues in the small intestine where pancreatic amylase breaks down complex carbohydrates into disaccharides. Enzymes like lactase, sucrase, and maltase further break down disaccharides into monosaccharides. Monosaccharides (glucose, fructose, galactose) are then absorbed through the intestinal walls into the bloodstream.

Metabolism of Carbohydrates

After absorption, glucose is transported to cells to be used for energy. Excess glucose can be converted into glycogen and stored in the liver and muscles. If glycogen stores are full, excess glucose can be converted into fat for long-term storage.

Dietary Deficiency Related to Carbohydrates

A deficiency in carbohydrates can lead to:

Lack of energy: Leading to fatigue and weakness.
Weight loss: As the body starts breaking down protein and fat for energy.
Ketosis: An abnormal accumulation of ketone bodies in the blood due to incomplete fat metabolism, leading to symptoms like nausea and bad breath.
Protein wasting: When proteins are used for energy instead of their primary functions.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to mention different types of foods they eat daily. The teacher then asks what nutrient group these foods belong to.
Pupils’ Activity: Pupils respond by mentioning various foods and try to categorize them.
Learning Point: Pupils recall previous knowledge about food and nutrients, setting the stage for the new topic.

Step 2: Explanation of Types and Chemical Structure of Carbohydrates

Time: 7 minutes
Teaching Skill: Explanation/Classification
Teacher’s Activity: The teacher defines carbohydrates and explains their classification into monosaccharides, disaccharides, and polysaccharides, giving examples for each. The teacher uses the food chart to point out examples.
Pupils’ Activity: Pupils listen attentively, take notes, and ask questions for clarification.
Learning Point: Pupils learn the definition and different types of carbohydrates.

Step 3: Discussion on Functions of Carbohydrates

Time: 5 minutes
Teaching Skill: Discussion/Elucidation
Teacher’s Activity: The teacher leads a discussion on the various functions of carbohydrates in the human body, emphasizing their role as the primary energy source.
Pupils’ Activity: Pupils contribute to the discussion by stating functions and taking notes.
Learning Point: Pupils understand the importance of carbohydrates for body functions.

Step 4: Identification of Sources of Carbohydrates

Time: 5 minutes
Teaching Skill: Demonstration/Identification
Teacher’s Activity: The teacher displays the samples of carbohydrate-rich foods and asks pupils to identify them and state why they are considered carbohydrate sources.
Pupils’ Activity: Pupils identify the food samples and mention their carbohydrate content.
Learning Point: Pupils can identify common food sources of carbohydrates.

Step 5: Explanation of Digestion and Absorption of Carbohydrates

Time: 8 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher uses the digestion diagram chart to explain the process of carbohydrate digestion from the mouth to the small intestine, and how the absorbed monosaccharides enter the bloodstream.
Pupils’ Activity: Pupils observe the chart, listen to the explanation, and ask questions.
Learning Point: Pupils understand how carbohydrates are broken down and utilized by the body.

Step 6: Discussion on Metabolism and Dietary Deficiency

Time: 5 minutes
Teaching Skill: Discussion/Problem-solving
Teacher’s Activity: The teacher explains what happens to absorbed glucose (metabolism) and then discusses the effects of inadequate carbohydrate intake (dietary deficiency).
Pupils’ Activity: Pupils listen, take notes, and discuss possible consequences of carbohydrate deficiency.
Learning Point: Pupils learn about carbohydrate metabolism and the health risks of deficiency.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define carbohydrates.
Mention two types of monosaccharides.
State three functions of carbohydrates in the body.
List four common food sources of carbohydrates.
Explain briefly what happens during carbohydrate digestion in the small intestine.
Identify two effects of carbohydrate deficiency.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 3 minutes
Teaching Skill: Summarization/Consolidation
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the importance of carbohydrates in a balanced diet. The teacher then assigns homework.
Pupils’ Activity: Pupils listen and copy the assigned homework.
Learning Point: Pupils consolidate their learning and prepare for further study.

Lesson Keywords

Carbohydrates – Organic compounds providing the body’s main source of energy.
Monosaccharides – Simple sugars like glucose, fructose, and galactose.
Disaccharides – Sugars formed from two monosaccharide units, e.g., sucrose.
Polysaccharides – Complex carbohydrates made of many sugar units, e.g., starch, glycogen.
Digestion – The process of breaking down food into smaller molecules.
Absorption – The process by which digested nutrients pass into the bloodstream.
Metabolism – The chemical processes that occur within a living organism in order to maintain life.
Glycogen – The stored form of glucose in the liver and muscles.

Differentiation

For visual learners, the teacher will make extensive use of the food chart and digestion diagram. Auditory learners will benefit from the discussions and explanations. Kinesthetic learners will be engaged through identifying and arranging actual food samples. Group activities can be used to promote peer learning and discussion among all pupils.

Note for teachers using this lesson plan

Encourage pupils to relate the lesson content to their daily food intake. Emphasize the importance of balanced carbohydrate consumption, avoiding both deficiency and excess. Monitor pupil participation and understanding throughout the lesson, providing additional examples or explanations where necessary.