Nutrients and Their Importance

Nutrients and Their Importance

• Nutrients are chemical substances in food utilized by organisms.
• Necessary for energy production and growth requirements.
• Essential elements in food include Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, and Sulfur.

Trace Elements

• Trace elements are required in small quantities.
• Example of a trace element: Iron.

Biomolecules in Food

• Major types of biomolecules: Carbohydrates, Lipids, Proteins, Vitamins, and Water.
• Carbohydrates contain Carbon, Hydrogen, and Oxygen, usually in the ratio of Cx(H2O)y.

Carbohydrates

• Monosaccharides are single sugar units (e.g., Glucose).
• Disaccharides consist of two sugar units (e.g., Sucrose).
• Polysaccharides are many sugar units (e.g., Starch).
• Common carbohydrate sources: Bread, Rice, Pasta.
• Structural role: Cellulose forms plant cell walls.
• Metabolic role: Carbohydrates supply energy during respiration.

Lipids

• Composed of Carbon, Hydrogen, and Oxygen.
• Fats are solid; oils are liquid at room temperature.
• Carbohydrates have a fixed elemental ratio, unlike lipids.
• Basic structure of lipids: Triglyceride (glycerol + three fatty acids).
• Phospholipids contain a phosphate group, while triglycerides do not.
• Lipid sources: Butter, Oil.
• Structural role: Phospholipids are crucial for cell membrane structure.
• Metabolic role: Lipids serve as an energy source.

Proteins

• Composed of Carbon, Hydrogen, Oxygen, and Nitrogen, with possible Phosphorus and Sulfur.
• Made up of amino acids.
• Protein sources: Milk, Meat.
• Structural role: Keratin is found in hair.
• Metabolic role: Enzymes, which are proteins, facilitate chemical reactions.

Vitamins and Minerals

• Water-soluble vitamin example: Vitamin C; deficiency disorder: Scurvy.
• Fat-soluble vitamin example: Vitamin D; deficiency disorder: Rickets.
• Essential minerals for plants include Nitrogen (for growth) and Phosphorus (for energy transfer).
• Essential minerals for animals include Calcium (for bone health) and Iron (for oxygen transport).

Role of Water

• Water is an excellent solvent and composes most of body fluids.
• Constitutes 70-95% of cell contents.

Qualitative Food Testing

• Biuret reagent is used to test for protein presence, indicated by a lilac color.
• Benedict's solution tests for reducing sugars; the presence indicated by a brick-red color (requires heat but not boiling).
• Brown paper test identifies lipids; requires drying to confirm the presence of lipid, not water.
• Control in tests is typically water to ensure accurate results.