SUBJECT: SCIENCE FORM: 5

1 NUTRIENT REQUIREMENTS OF PLANTS

1.1 PHOTOSYNTHESIS IN GREEN PLANTS

Definition: Synthesize of food process by green plants in presence of sunlight using water (H2O) and carbon dioxide (CO2).

Water + Carbon Dioxide Glucose + Oxygen

How photosynthesis occur:

NUTRITION

1. NUTRITION AND GOOD EATING HABITS

4. MANAGING FOOD RESOURCES

3. THE NITROGEN CYCLE

2. NUTRIENT REQUIREMENT PLANTS

sunlight

chlorophyll

Watero Absorbed

through the roots

o Transport along xylem to the leaves

Carbon dioxideo Absorbed

from air through the stomata in leaves

Glucoseo Combination

of hydrogen and carbon dioxide

Oxygeno Waste

producto Released

from leaves through stomata

Sunlighto Supply

energy for this process

Chlorophyllo Absorb

sunlight

Importance of photosynthesis:

o Helps to maintain the balance of carbon dioxide and oxygen in atmosphereo Supply foods to green plants, animals and human being1.2 MACRONUTRIENTS

Definition: Minerals required by plants in large amount for their healthy growth

Macronutrients and their functions:

Macronutrient FunctionCarbon (C) To form carbohydrates, proteins and fats

Hydrogen (H) “Oxygen (O) “Nitrogen (N) To form hormones, proteins, nucleic acid and chlorophyll

Phosphorus (P) To form proteins and nucleic acidTo stimulate the production of flowers and fruits

Potassium (K) To form carbohydrates, proteins and new cellsTo build up resistance for disease

Calcium (Ca) To form cell wallsFor growth

Magnesium (Mg) To form chlorophyllTo activate certain enzymes

Sulphur (S) To form certain amino acidsFor growth

1.3 MICRONUTRIENTS

Definition: Minerals required by plants in very small amount for their healthy growth. They also have known as trace elements.

Micronutrients and their functions:

Micronutrient FunctionBoron (B) To help in the breaking up of the carbohydrates

Molybdenum (Mo) To help nitrogen to carry out its functionsZinc (Zn) To activate certain enzymes

Manganese (Mn) “Copper (Cu) To form enzymes for photosynthesis

Iron (Fe) To form chlorophyll

Effects of Deficiency of Nitrogen, Phosphorus and Potassium on Plant Growth

Macronutrient Deficiency symptomNitrogen (N) Stunted (short) growth

Leaves are small, yellow and drop off easily Phosphorus (P) Poor growth especially the roots.

Few flower and fruitsPotassium (K) Leaves turn yellow (chlorosis)

Plants are weak and die before maturing.

2 NITROGEN CYCLE AND ITS IMPORTANCE.

2.1 NITROGEN CYCLE

Nitrogen in atmosphere

Nitrites Plant proteins

Nitrates Nitrates

Ammonium in compounds Animal proteins

Absorption

NutritionAction of nitrifying bacteria

Synthesis of nitrogen fixing bacteria

Lightning

Absorption

Decay by bacteria and fungi

Action of nitrifying bacteria

Action of denitrifying bacteria

Decay by bacteria and fungi

2.2 IMPORTANCE OF NITROGEN CYCLE

o Maintain soil fertilityo Increasing production of cropso Maintaining the amount of nitrogen in atmosphereo Reducing pollution of the environment

3 MANAGING FOOD RESOURCES AND HEALTHY EATING HABITS

- Plant and animals are said to be our food resources. Thus, we should manage these food resources so that there will be a continuous food supply for us.- To manage these food resources, we have to do a lot of following things: Avoid wastage Ensure that we do not cook more than we can eat.

- Besides, we have to practice healthy eating habits in our daily life. It can be done by: Eat well-balanced diet Avoid skipping meals especially breakfast Eat our food slowly so that the brain has enough time to register fullness. Avoid taking excessive amount of sugars, salts and fats in our food