1. Nutrients Chemicals of Living Things

2. Biological Macromolecules • Living things are composed of nonliving materials (molecules and ions) • Some molecules and ions are simple (water, phosphates, hydrogen ions, sodium ions, calcium ions, etc). They are inorganic matter. • Other molecules contain carbon bonded to hydrogen and other atoms such as oxygen, sulfur, and nitrogen. They are called organic molecules • Larger and more complex organic molecules are called macromolecules

3. Macromolecules and Nutrients • Macromolecules are known as nutrients (raw materials that our body needs to obtain energy for survival) • Energy released from these macromolecules is used to maintain the body's metabolism – all the chemical processes carried out by cells to maintain life • Biological macromolecules include: - Carbohydrates - Proteins - Lipids - Nucleic acids

4. Monomers and Polymers • Cells are able to make macromolecules by joining smaller subunit molecules together into chains known as polymers. • Polymers – large molecules consisting of identical or similar building-block molecules in a chain. • Monomers – the individual building-block molecules in a polymer

6. Carbohydrates • The most important source of energy • Make up the largest component in most diets • Provide short-term energy to cells (energy that can be quickly utilized) • Structurally, consist of C, H, and O • Human body cannot make these important chemicals by itself (relies on plants as the source of carbohydrates)

7. Classification of Carbohydrates • Monosaccharides – simple sugars made up of a single sugar molecule (or monomer) • Examples of monosaccharides: Glucose (C6H12O6) is found in all cells of our body and is the primary source of energy Fructose – a simple sugar found in fruits Galactose – one of the sugars found in milk

9. Disaccharides • Sugars that consist of two monosaccharides • Formed by condensation reactions • Examples of disaccharides include: • Maltose – made from two glucose molecules. • Sucrose (or table sugar) – made from a combination of a glucose and a fructose molecule • Lactose (found in milk) is composed of glucose and galactose.

11. Polysaccharides • Complex carbohydrates (large molecules) • Polymers of monosaccharides such as glucose • Some important polysaccharides include: • Starch – the energy storage molecule in plants and a good source of energy for human cells • Glycogen – the short-term energy storage molecule in human cells • Cellulose – the molecule that makes up plant cell walls; humans and others animals cannot break it down into glucose

13. Lipids • Organic compounds that include fats, phospholipids, and steroids • Supply energy to the cells of the body • Unlike carbohydrates, lipids are not broken down easily by our body • Excellent energy storage compound • Insoluble in water; they are only soluble in substances such as acetone, alcohol, etc.

14. Fats • Consist of two structural units: one glycerol molecule and three fatty acids • Fatty acids – long C-H chains with a carboxyl group COOH at one end • Saturated fatty acids – contain the maximum number of H atoms possible; no double bonds between C atoms (e.g. animal fats) • Unsaturated fatty acids- have one or more double bonds between C atoms (plant fats)

16. Other Lipids • Phospholipids - the main components of cell membranes; composed of a phosphate group (soluble in water) and two fatty acids molecule (insoluble in water) attached to the glycerol backbone • Steroids – consist of 4 linked C rings; include cholesterol and certain sex hormones • Cholesterol is used by our body to make certain hormones; it is also an important part of the cell membrane. Two much of cholesterol can cause heart and/or arterial disease

17. Structure of Phospholipids

18. Proteins • Proteins direct and control the chemical reactions in life processes (part of the cell membrane; provide support and shape to cells; enzymes) • Proteins are composed of 20 different amino acid building blocks; a chain of amino acids can be referred to as a polypeptide • Essential amino acids – there are 8 amino acids that the body cannot synthesize; they must be obtained from food

20. Nucleic Acid • Two types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) • They are not nutrients but they are essential for all living things – they direct growth and development of all organisms using a chemical code • The sequence of amino acids in a protein molecule is determined by the sequence of nucleotide bases in a segment of DNA called a gene

21. Enzymes • Macromolecules must be chemically broken down into small molecules before the body can use them • Only small molecules can be absorbed by the cells lining the small intestine • The breakdown of the chemical bonds between macromolecules involves enzymes • Enzymes are a special class of protein molecules that act as catalysts

22. MicronutrientsVitamins and Minerals • Important in maintaining the overall metabolism of the body • Needed on a daily basis to sustain life and maintain health • Taken in extremely small quantities • Cannot be used as an energy source

23. Vitamins • Organic compounds – contain C, H, O, N, and small amounts of other elements • Most of them act as coenzymes (joining to specific enzymes) • Two major groups: • Fat-soluble • Water-soluble

24. Fat-soluble Vitamins • Vitamins A, D, E, and K • Found in the fats and oils that we eat (that’s why a certain amount of fat intake is part of a healthy diet) • Cannot be excreted; they break down over time as they participate in metabolic processes

25. Water-soluble Vitamins • Include vitamins B and C • Eliminated from the body relatively quickly (that’s why a daily intake is recommended) • When too much of B and C vitamins is taken, the excess is excreted in the urine

26. Minerals • Inorganic compounds required by the body • Found in some of the most important molecules in the body Examples: • Hemoglobin-the protein in the red blood cells has 4 iron atoms • Calcium is a major component for healthy teeth and bones The body doesn’t destroy the minerals but loses them in sweat and urine; it is important to replenish them through a balanced diet - fruits, whole grains, meats, and vegetables.