ANIMAL NUTRITION

Subject:

Biology

 

Class:

SS 1

 

Term:

First Term / 1st Term

 

Week:

Week 10

 

Topic:

ANIMAL NUTRITION

 

 

 

Previous Knowledge: The pupils have previous knowledge of

 

THE PROPERTIES AND FUNCTIONS OF THE CELL

 

that was taught in their previous lesson.

 

 

Behavioural  Objectives : At the end of the lesson, learners will be able to

• Define animal nutrition
• Say the classification of animals based on their mode of feeding
• List classes of food

 

 

Instructional Materials 

• Wall charts
• Online Resource
• Textbooks
• Sodium hydroxide, rubber bung, conical flask, potted plants, clamp, Vaseline
• Laptop
• Flash cards
• Spirogyra fertilizers yeast and rat.
• www.edudelighttutors.com

 

Methods of Teaching 

• Role modelling
• Questions and Answers
• Explanation
• Discussion
• Recitation
• Imitation
• Story Telling
• Dramatization

 

Content: 

ANIMAL NUTRITION

All living organisms need food for their survival and daily activities. Plants can manufacture their food through the process of photosynthesis; hence they are called autotrophs. On the other hand, animals cannot manufacture their feed as they depend on plants directly or indirectly for their food, hence they are called heterotrophs.

Animals sometimes are classified according to the type of food they eat. On this basis, they are classified into three groups, namely: 

1. Carnivorous animals: These animals feed only on flesh or other animals. dog, lion, lizard, snake, cat, etc.
2. Herbivorous animals: These animals feed on plants, e. g. goat, cattle, sheep, rabbit etc.
3. Omnivorous animals: These animals feed on both plants and animals, e.g. man, pig, etc.

Classification of Food Substances

All the food eaten or taken in by an animal can be classified or divided into seven groups of food substances. These Food substances are (i) Carbohydrates (ii) Proteins (iii) Fats and oils(iv) Mineral salts (v) Vitamins (vi) Water and(vii) Roughages.

The composition, sources and functions of these food substances are explained as follows:

Carbohydrates

Composition: Carbohydrate is made up of carbon, hydrogen and oxygen. 

Sources: The main sources of carbohydrate include yam, rice, maize, millet, guinea corn, potatoes, bread, Garri, etc.

Types of Carbohydrates

1. Monocarbide (Simple sugars)

(b) Disaccharides (Reducing sugars)

(c) Polysaccharides (Complex sugars)

Importance of Carbohydrates

(i) Carbohydrate provides energy required by animals for their daily activities. 

(ii) It also provides heat, during its oxidation, used in maintaining the body temperature.

(iii) Carbohydrates are also used to build certain body parts, e.g. exoskeleton of arthropods.

(iv) Mucus, an important lubricant in our bodies, is composed of carbohydrates.

PROTEINS

Proteins are complex molecules and are made of smaller units called amino acids. Proteins have to be digested to amino acids before they are absorbed in the bodies of animals. The breakdown of proteins during digestion takes place in the following stages:

protein —> peptones —+ polypeptides —>amino acids.

Composition of protein: Protein is composed of carbon, hydrogen, oxygen, nitrogen and sometimes phosphorus and Sulphur.

Sources of proteins: Animal sources of proteins are milk, egg, fish, cheese, meat and chicken while plant sources are beans (cowpea), groundnut, soya beans etc. 

 Importance of Protein

(i) Protein is used for the growth of young ones.

(ii) It is used for the repair of worn-out tissues or cell.

(iii) It aids preproduction.

(iv) It is used for the production of enzymes.

(v) It is also used for the production of hormones.

(vi) It is used for tissue and cell formation (bodybuilding).

FATS AND OILS

Fats and oils are also called lipids. Fats are solid lipids. Fat are solid liquid at room temperature. They are hydrolyzed during digestion to fatty acids and glycerol which can be absorbed into the lymphatic system.

Composition offats and oils: Fats and oils are composed of carbon, hydrogen and little oxygen. 

Sources of fats and oils: Sources of fats and oils include palm oil, groundnut, soyabean oil, melon oil, butter, fish, cheese, margarine, etc.

Importance of Fats and Oil

(i) Fats and oils provide more energy to animals than carbohydrates.

(ii) Fats supply essential fatty acids to animals.

(iii)Fats and oils also provide fat soluble vitamins. 

(iv)They help in the maintenance of body temperature.

MINERAL SALTS

Animals require various mineral salts for metabolic activities within the body. Except for sodium chloride (table salt) and few medicines like iron tablets which can be taken directly by man, other mineral salts are usually taken in minute quantity through the food we eat Lack of these mineral salts will result in nutritional deficiency. 

Classes of mineral salts: These include calcium, phosphorus, magnesium, potassium, sulphur, sodium, chlorine, iron, iodine, manganese, fluorine, copper and cobalt. 

 

ASSIGNMENT

1. Mention the classed of mineral with the source, functions and deficiency symptoms.
2. List the group of vitamin with the source, functions and deficiency symptoms

WATER 

Composition of water: Water is com; used of two elements—hyclr0gen and oxygen.

Sources of water: Sources of water available to animals include metabolic water from food, drinking water from rivers, taps, rain, pond etc.

Importance of Water

Water is very important to animals in the following ways:

(i) Water is required for metabolic activities in the body.

(ii) It is necessary for the digestion of food.

(iii) It can be used for the maintenance of body temperature.

(iv) Water is the main component of plants and animals, e.g. it forms about 75% of man’s body. 

(v) It acts as a solvent for soluble food substances in digestion. 

(vi) It acts as a medium of transportation for nutrients.

(vii) It constitutes a greater part of blood.

(viii) It also aids the excretion of metabolic waste products from the body, e.g. urine. 

(ix) It also helps to maintain the osmotic content of the body tissues. 

(X) It is the basis of body secretion from endocrine glands.

ROUGHAGES

Roughages consist of indigestible biomaterials derived from vegetables, fruits, carbohydrates and proteins. Roughages providebulk to the intestinal content thereby stimulating the movement of bowel. Lack of roughages in the diet can cause constipation. Roughages are easily digested by micro-organisms in the intestinal tract.

BALANCED DIET

Balanced diet is a diet containing the correct proportion or the right amount of all six food substances required by an organism or man. The balanced diet must contain the six food substances such as carbohydrates, proteins, fats and oils, minerals, vitamins and water.

In terms of the percentage composition of the food substances, a balanced diet should contain 15% of proteins, l5% of fats and oils, l0% of vitamins, minerals and water, and 60% of carbohydrates. A balanced diet must be taken at these proportions for normal growth, development and all activities of the body.

IMPORTANCE OF BALANCED DIET

Balanced diet is important to the body in the following ways:

1. A balanced diet makes us healthy and by so doing makes us to be resistant to diseases.
2. It encourages growth and normal development of the body.
3. It also provides energy required for normal activities. 
4. Balanced diet prevents malnutrition deficiency or diseases. Lack of some food substances, e.g. protein in a diet can cause a nutritional disease called kwashiorkor in children which is characterized by a very big head, narrow neck, big, swollen and shiny stomach, flat buttock and very slender and narrow legs.

 

PACTICAL

Food Tests

1. Test for protein
2. Test for starch
3. Test for simple sugar
4. Test for reducing sugar
5. Test for fat and oils
6. Test for water

ASSIGNMENT

1. Define Enzymes.
2. Mention and explain two types of enzymes.
3. State the classes of enzymes with the action substance.

CHARACTERISTICS OF ENZYMES

1. All enzymes are proteins in nature
2. Enzymes are usually involved in reversible reactions.

iii. Enzymes are affected by the PH acidity or alkalinity of their surroundings.

1. Enzymes accelerate the rate of chemical reaction.
2. Each enzyme is specific in action, i.e. an enzymes or a group of enzyme deal with only one process.
3. Enzymes have a specific temperature range above or below which they become inactive or denatured.

(vii) Enzymes, like any other catalyst act in verya small quantities and catalyse large amountof substrate.

(viii) Enzymes do not lose their chemical composition at the end of a reaction. In otherwords.enzymes are not used up or changedduring reaction.

(ix) Enzymes can function outside organismsproducing them.

(x) Enzymes require the presence of non-proteins molecules calledfor their catalytic function.

Functions of Digestive Enzymes

(i) Enzymes help in breaking down proteins foods into amino acids.

(ii) They also help in breaking down fatsoils into fatty acids and glycerol.

(iii) They help in breaking down of carbohydrates into glucose, fructose and galactose.

(iv) They aid the absorption of digested food through the addition of water to the food. 

ENZYMES, SOURCE, LOCATION, SUBSTRATE ACTED UPON AND EFFECTS OR PRODUCTS 

	Enzyme	Source	Location	Substrate acted upon	Effect/Product
1	Ptyalin	Salivary gland	Mouth	Starch	Partial hydrolysis of starch maltose
2	Renin	Gastric gland	Stomach	Proteins	It coagulates or curdles milk
3	Pepsin	Gastric gland	Stomach	Protein	It converts protein to peptones
4	Amylse	Pancreas	Duodenum	Starch	It converts starch to maltose
5	Pancreatic liapse	Pancreas	Duodenum	Fats and oils	It converts fats and oils to acids and glycerol.
6	Trypsin	Pancreas	Duodenum	Proteins or peptones	It converts proteins or peptone to polypeptides.

 

ASSIGNMENT

1. Mention five types of enzymes, source, location, substrate acted upon and affects or products.

 

MODES OF NUTRITION

All living organisms are capable of carrying out different modes of nutrition. However, the mode of nutrition can be grouped into two major classes referred to as autotrophic heterotrophic nutrition.

Autotrophic Nutrition

This is the type of nutrition in which organisms are able to manufacture their food. Organisms which can manufacture their food are called autotrophs. 

Autotrophic nutrition is further divided into two groups. These are holophytic or photosynthesis nutrition and chemosynthetic nutrition.

1. Holophytic (Photosynthetic) nutrition: Holophytic nutrition is the type of nutrition in which all green plants are able to manufacture their own food making use of carbon dioxide and water in the presence of sunlight. This process is called photosynthesis. The green plant derived their energy for making this food from the sunlight. This energy is usually trapped by chlorophyll. The process of photosynthesis can be represented by this chemical equation.

6C02 + 6H2O +  Light energy C6H12O + 602

Chlorophyll

Carbon (iv) oxide) (water) (Carbohydrate) (Oxygen)

 

Examples of organisms that carry out or exhibit photosynthetic nutrition are all green plants such as flowering plants, Spirogyra, Euglena, blue-green alga (nostoc) etc.

2. Chemosynthetic nutrition: Chemosynthetic nutrition is another mode of nutrition in which certain bacteria are able to synthesise organic compounds from simple inorganic materials such as carbon (iv) oxide, ammonia, water or nitrite to manufacture their food.  Examples of organisms or bacteria that exhibit chemosynthetic nutrition are: –
3. Nitrosomonas which converts ammonia to nitrite

2NH3+ 3O2 Nitrosomonas 2HNO2+ 2H2O + Energy

(Ammonia) (oxygen) (Nitrite) (water)

 

1. Nitrobacter which converts nitrites to nitrate to nitrate 

HNO2 + O2 Nitrobacter      HNO3+ Energy.

2. Heterotrophic Nutrition

This is the type of nutrition in which organisms cannot manufacture their food but depend directly or indirectly on plants (autotrophs) for their food. Organisms which cannot manufacture their food are called heterotrophs. Most animals, fungi, protozoa and some bacteria belong to this group.

Heterotrophic nutrition is also sub-divided into the following groups or types:

1. Holozoic nutrition: Holozoic nutrition involves the feeding on other organisms or solid organic substances synthesized by green plants. The organisms ingest, digest and assimilate this food into their bodies. Examples are:

 

1. Carnivores like cats, dogs, lions etc. that feed on flesh.
2. Herbivores like sheep, goats, rabbits, etc. that feed on plants.
3. Omnivores like man, pig etc. that feed on both flesh and vegetables or plants.
4. Scavengers like vultures that feed on dead animals.
5. Parasitic nutrition: This is the type of nutrition in which certain organisms feed-on another organism in order to derive nourishment from it. This mode of nutrition is called parasitic nutrition while the association is called parasitism. Parasitism is an association between two organisms, usually of different species in which one called the parasite gains from the association while the other called the hosts harmed or suffer losses. Examples of parasites are:

(a) Animal parasites like Tapeworm, plasmodium, roundworms, liver flukes, ticks, fleas, bugs, guinea worm hook worm etc.

3. Saprophytic nutrition: This is the type of nutrition in which certain organisms called saprophytes feed on dead and decaying organic materials. Examples are fungi, such as Rhizopus, mushroom, mucor, etc.
4. Symbiotic Nutrition: –This is the type of nutrition in which two organisms of different species called symbionts live together and derive nutrients or food from each other.  Examples are:
5. fixing bacteria and root nodules of leguminous plants.
6. Algae and fungi in a lichen.
7. Sea anemones and hermit crabs
8. Termites and protozoa living in the gut
9. Carnivorous or insectivorous plant:- Carnivorous or insectivorous plants are equipped with devices for trapping, digesting and absorbing nutritive compounds from the bodies of insects and other small organisms.  They have green leaves to help them carry out photosynthetic nutrition.

Examples are:

1. sundew (drosera)
2. Bladderwort
3. Pitcher- Plant of the nepenthes and sarracenia

ASSIGNMENT

1. Describe saprophytic nutrition and give three examples of organisms associated with the mode of nutrition.
2. List four mode of nutrition found in plants

The topic is presented step by step

Step 1: The class teacher revises the old topic

Step 2: The class teacher introduces the new topic

Step 3: The class teacher allows the pupils to give their own contributions and gives room for pupils” participation

 

Class Teacher and Students Activities. Interaction or Participation 

This involves class teacher and pupils’ interaction, conversation, imitation or modeling through discussion, play method or just by recitation or asking and answering questions that are related to the topic that has just been taught.

 

Teacher Activities

1. The teacher introduces the subject biology and mentions the two major fields botany and zoology
2. List the steps involved in scientific methods
3. Prompt the students to elicit facts on the usefulness of biology

 

 

Students Activities.

1. Students listen attentively
2. State the steps involved in scientific methods after the teacher
3. Mention the usefulness of biology as a career

 

 

EVALUATION

1. Explain the terms; Aerobic and anaerobic respiration.
2. Discuss with a diagram the glycolytic pathway and Kreb’s cycle.
3. State the following equations: respiration, lactic acid, and fermentation.

 

 

 

 

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