Lesson Notes By Weeks and Term - Senior Secondary 1

Nutrition in animals

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TERM – 1ST TERM

WEEK SEVEN

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Biology

Topic: Nutrition in Animals

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

  1. Define food substances
  2. Identify the types and sources of food

iii. Define balance diet and identify its significance

  1. Identify some basic digestive enzymes and their characteristics
  2. Explain cellular respiration and its types

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION

TEACHER’S ACTIVITY

STUDENT’S

ACTIVITY

STEP 1

INTRODUCTION

The teacher explains food substances and their sources, and give local examples of food substances for better understanding of the students

 

Students pay

attention

STEP 2

EXPLANATION

Teacher discusses balance diet and its significance

Students pay

attention and

participate

 

STEP 3

DEMONSTRATIO

N

Teacher explains basic digestive enzymes and goes ahead to discuss cellular respiration

 

Students pay

attention and

participate

STEP 4

NOTE TAKING

The teacher writes a summarized

note on the board

 

The students

copy the note in

their books

 

NOTE

Nutrition in Animals

Food substances are the various types of compounds and elements that organisms consume to obtain energy, nutrients, and support growth and metabolic functions. These substances can be broadly categorized into macronutrients and micronutrients.

  1. Macronutrients:

   - Carbohydrates: Main sources of energy, found in foods like grains, fruits, and vegetables.

   - Proteins: Essential for growth, repair, and maintenance of tissues, found in foods like meat, dairy, and legumes.

   - Fats: Provide energy and support cell structure, found in oils, butter, and nuts.

  1. Micronutrients:

   - Vitamins: Organic compounds essential for various physiological functions. Examples include vitamin C in citrus fruits and vitamin A in carrots.

   - Minerals: Inorganic elements crucial for body functions. Examples include calcium in dairy products and iron in red meat.

  1. Water: Essential for various biological processes, including digestion and temperature regulation. Found in various beverages and food with high water content.
  2. Fiber: A type of carbohydrate important for digestive health. Found in fruits, vegetables, and whole grains.

Sources of food

The following are some common sources of food along with local examples:

  1. Grains (Wheat, rice, barley, maize, millet, and oats.)
  2. Fruits (Apples, bananas, oranges, mangoes, strawberries, and grapes.)
  3. Vegetables (Carrots, broccoli, spinach, potatoes, tomatoes, and bell peppers.)
  4. Proteins:

   - Meat: Chicken, beef, pork, lamb.

   - Fish: Salmon, tuna, tilapia.

   - Legumes: Lentils, chickpeas, black beans.

   - Dairy: Milk, cheese, yogurt.

  1. Fats and Oils) Olive oil, coconut oil, butter, and avocados.)
  2. Beverages (Coffee, tea, fruit juices, and traditional beverages specific to the region.)
  3. Seafood (Shrimp, crab, lobster, and various local fish varieties based on geographic location.)
  4. Cereals and Pulses(Rice, wheat, oats, lentils, and chickpeas.)

Balance diet

A balanced diet is one that provides the necessary nutrients in the right proportions to maintain overall health and well-being. It includes a variety of foods that supply the body with the essential nutrients required for optimal functioning. Here's why a balanced diet is important:

  1. Nutrient Supply: A balanced diet ensures the intake of essential nutrients such as carbohydrates, proteins, fats, vitamins, and minerals, which are crucial for various physiological functions, growth, and energy production.
  2. Weight Management: It helps in maintaining a healthy weight by providing the body with the right amount of calories. Balanced diets with appropriate portions contribute to weight control and reduce the risk of obesity-related conditions.
  3. Disease Prevention: A well-balanced diet can help prevent and manage chronic diseases such as heart disease, diabetes, and certain types of cancer. Nutrient-rich foods support the immune system and overall health.
  4. Energy Levels: Proper nutrition provides the energy needed for daily activities and supports metabolic processes. Carbohydrates, proteins, and fats contribute to sustained energy throughout the day.
  5. Digestive Health: Fiber from fruits, vegetables, and whole grains aids digestion and helps prevent constipation. It also supports a healthy gut microbiome.
  6. Bone Health: Adequate calcium and vitamin D intake, often found in dairy products and certain vegetables, is essential for maintaining strong and healthy bones.
  7. Hydration: A balanced diet includes an adequate intake of fluids, contributing to proper hydration. Water is essential for various bodily functions, including temperature regulation and nutrient transport.
  8. Optimal Growth and Development: A balanced diet is crucial for children and adolescents to support proper growth, development, and learning.

Digestive enzymes

Digestive enzymes are specialized proteins produced by the body to facilitate the breakdown of complex food molecules into simpler and absorbable forms. These enzymes are essential for the proper digestion and absorption of nutrients in the gastrointestinal tract. There are several types of digestive enzymes, each designed to target specific types of macromolecules:

Characteristics of Digestive Enzymes

  1. Digestive enzymes are highly specific, each acting on a particular type of substrate (food molecule). For example, amylases act on carbohydrates, while lipases act on fats.
  2. Enzymes function as biological catalysts, accelerating the rate of chemical reactions in the digestive process without being consumed in the process.
  3. Enzymes are sensitive to temperature changes. They have an optimal temperature at which they work most efficiently. Extreme temperatures can denature enzymes and affect their activity.
  4. Enzymes have an optimal pH at which they function best. Changes in pH can affect their structure and, consequently, their activity.
  5. Digestive enzymes typically have names that end in "-ase." For example, amylase, protease, and lipase are common digestive enzymes.

Classes of Digestive Enzymes

  1. Amylases: Is found on the salivary glands (salivary amylase) and pancreas (pancreatic amylase). It acts on starches and carbohydrates, breaking down starches into simpler sugars like maltose.
  2. Proteases: found in the stomach (pepsin) and pancreas (trypsin, chymotrypsin). It's acts on proteins, breaking down proteins into amino acids.
  3. Lipases: found in the pancreas and small intestine

 It's acts on fats or triglycerides, breaking down fats into fatty acids and glycerol.

  1. Nucleases: found in the pancreas and small intestine. It acts on nucleic acids (DNA and RNA), breaking down nucleic acids into nucleotides.

Functions of Digestive Enzymes

  1. Enzymes begin the breakdown of complex food molecules into simpler forms, starting the digestive process.
  2. Digestive enzymes break down nutrients into forms that can be absorbed by the body through the walls of the digestive tract.
  3. The breakdown of carbohydrates, proteins, and fats by enzymes releases energy that can be utilized by the body for various metabolic processes.
  4. Amino acids derived from the digestion of proteins are essential for tissue repair and growth.
  5. Enzymes play a role in various cellular processes, including signaling pathways and metabolic reactions.

Cellular respiration

Cellular respiration is the process by which cells break down organic molecules, typically glucose, to release energy in the form of ATP (adenosine triphosphate). This energy is then used for various cellular activities. Cellular respiration can be broadly categorized into three main stages:

  1. Glycolysis: Cytoplasm.

   - Glucose, a six-carbon sugar, is broken down into two molecules of pyruvate, a three-carbon compound. This process produces a small amount of ATP and NADH.

  1. Citric Acid Cycle (Krebs Cycle): Mitochondrial matrix.

   - Each pyruvate from glycolysis is further broken down, releasing carbon dioxide. This process generates NADH and FADH2, which carry high-energy electrons to the next stage.

  1. Electron Transport Chain (ETC) and Oxidative Phosphorylation: Inner mitochondrial membrane.

   - High-energy electrons from NADH and FADH2 move through a series of protein complexes in the inner mitochondrial membrane, creating a flow of protons (H+) across the membrane. This flow is used to generate ATP through a process called oxidative phosphorylation.

Overall Equation for Cellular Respiration:

C6H12O6 (glucose) + 6O2 (oxygen) 6CO2 (carbon dioxide) + 6H2O (water) + Energy (as ATP)

Aerobic Respiration: Aerobic respiration is a form of cellular respiration that occurs in the presence of oxygen. It takes place in the cytoplasm.

The overall chemical equation for aerobic respiration is as follows:C6H12O6 (glucose) + 6O2 (oxygen)  6CO2 (carbon dioxide) + 6H2O (water) + Energy (as ATP)

Anaerobic Respiration:  Anaerobic respiration is a form of cellular respiration that occurs in the absence of oxygen. It also takes place in the cytoplasm, as in aerobic respiration.

NOTE: Both aerobic and anaerobic respiration are crucial for cellular energy production, but aerobic respiration is more favorable when oxygen is available due to its higher efficiency. Anaerobic respiration is a backup mechanism used when oxygen is limited.

EVALUATION: 1.What is cellular respiration

  1. Differentiate between aerobic and anaerobic respiration
  2. Define digestive enzymes and mention at least four sources of digestive enzymes
  3. Discuss food substance, with their respective sources.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively