Biological Molecules and Nutrients

Biological Molecules

• Living organisms need around 25 elements for growth
• Carbon (C), oxygen (O), and hydrogen (H) are the most common chemical elements in living things
• Sugar, starch, fat, oil, wax, and proteins are called organic molecules because they are primarily made of carbon and hydrogen

Nutrients

• Nutrients can be organic or inorganic
• Organic nutrients contain carbon and hydrogen (e.g., carbohydrates, lipids, proteins, and vitamins)
• Inorganic nutrients include minerals (e.g., calcium, iron)

Organic Compounds (Macronutrients)

• These are essential for life
• They are carbohydrates, proteins, and lipids
• They are needed in large amounts

Structure of Biological Macromolecules

• Many biological molecules are polymers, which are long chains of building blocks called monomers
• Monomers are the basic units of polymers
• Poly = many, Mono = 1
• These monomers link together to form long chains called polymers

Examples of Polymers

• Carbohydrates: Monosaccharides (simple sugars) link together to form disaccharides, oligosaccharides, and polysaccharides (starch, glycogen, cellulose)
• Nucleic acids: Nucleotides link together to form DNA and RNA
• Proteins: Amino acids link together to form polypeptides and proteins

Elements for Healthy Bodies

• Minerals:
  • Macrominerals are needed in large amounts (e.g., calcium, phosphorus, potassium, magnesium)
  • Trace elements are needed in small amounts (e.g., sulfur, iron, iodine)
• Plants need 18 elements
• Humans need 22 elements

Role of Key Elements

• Calcium is crucial for strong bones and teeth, nerve conduction, muscle contraction, and blood clotting
• Phosphorus is essential for bone formation and energy storage (ATP)
• Potassium regulates nerve signals, muscle activity, protein formation, and acid/base balance
• Magnesium is a component of bones and teeth, essential for enzyme function, and aids in nerve function
• Sulfur is used in some amino acids
• Iron is essential for oxygen transport in red blood cells
• Iodine is a component of thyroid hormones that regulate metabolism

Obtaining Minerals

• Humans cannot directly extract minerals from the ground
• Plants have special root hairs to absorb and transport minerals
• Plants use these minerals to create organic compounds like proteins and lipids
• We rely on plants to obtain these nutrients

Vitamins

• Vitamins are organic compounds essential for normal growth and nutrition
• They are needed in small quantities because they cannot be synthesized by the body
• There are 13 recognized vitamins

Water-soluble vs. Fat-soluble Vitamins

• Water-soluble vitamins are not stored and thus need more frequent intake
• Fat-soluble vitamins are stored in the liver and fatty tissues