Ch. 2 Part 2

1. Ch. 2Part 2 The Chemical Level of Organization

2. Inorganic vs. Organic • Inorganic • Usually lack carbon • Structurally simple • Include: • Water • Salts • Acids • Bases • Exceptions • Carbon dioxide (CO2) • Bicarbonate (HCO3-) • Carbonic acid (H2CO3) • Organic • Always contain carbon • Usually contain hydrogen • Always have covalent bonds • Most are large molecules made up of long chains

3. Role of Water in the Body • Most important inorganic compound for life • Almost all chemical reactions in the body need water to occur • Water is a solvent – dissolves important substances • Water has high heat capacity – doesn’t change temperatures easily • Water also acts as a lubricant (mucus) for joints, food movement, and between thoracic organs

4. Acids and Bases • This is also a review • pH scale – 0-14 • Acids (0-6) • Dissociate into hydrogen (H+) ions • Example: HCl • Bases (0-14) • Dissociate into hydroxide (OH-) ions • Example: NaOH

5. Acids and Bases in the Body • Buffer system – the body’s ability to control pH of certain fluids • Example: • Blood should have a pH of 7.35-7.45 • If the pH of blood gets to high or too low, serious complications can occur • A buffer system can help correct a pH imbalance • Does this by converting strong acids or bases into weak acids or bases

6. Organic Compounds of the Body • Organic compounds contain carbon • Organized into various structures • Macromolecules – large molecules • Polymers – built by putting together repeating monomers

7. Organic Compounds in the Body • In order to make a macromolecule • Dehydration synthesis must occur • Removing a water molecule, bind to monomers together • XOH + YOH → XOY + H2O • In order to break a macromolecule • Hydrolysis must occur • Adding a water molecule, break to monomers apart • XOY + H2O → XOH + YOH

8. 4 Major Groups of Organic Compounds • Carbohydrates • Lipids • Proteins • Nucleic Acids

9. Carbohydrates • Include: sugars, glycogen, starches, cellulose • Examples in our diet • Bread, pasta, rice, cereal • Function as a source of chemical energy (quick energy) • Made of carbon, hydrogen, and oxygen • 3 major groups • Monosaccharides • Disaccharides • polysaccharides

10. Carbohydrates • Monosaccharides – one sugar (sweet) • Glucose, fructose, galactose • Disaccharides – two sugars (sweet) • Sucrose, lactose, maltose • Polysaccharides – many sugars (not sweet) • Glycogen, starch, cellulose

11. Lipids • Include: triglycerides, phospholipids, steroids • Examples in our diet: • Fats, oils • Function as a source of energy storage • Made of carbon, hydrogen, and oxygen • Are hydrophobic – do not dissolve in water • Lipids are made of repeating fatty acids

12. Lipids • Triglycerides • Saturated fats – only single covalent bonds • Monounsaturated fats – one double bond • Polyunsaturated fats – more than one double bond • Phospholipids • Important part of cell membrane • Steroids • Important part of cell membrane, not all steroids are anabolic

13. Proteins • Include: proteins and enzymes • Examples in our diet: • Meat, fish, eggs, milk • Function as catalysts, protect against invaders, hormones, cell transport, building blocks of body • Made of carbon, hydrogen, oxygen, nitrogen, sulfur • Proteins are made of repeating amino acids

14. Proteins • 20 different amino acids • Amino acids are joined by peptide bonds to create polypeptide chains • Enzymes • Speed up chemical reactions within the body

15. Nucleic Acids • Include: DNA and RNA • Examples in our diet: • none – but we eat the building blocks (amino acids) • Function as inherited genetic material • Made of carbon, hydrogen, oxygen, nitrogen, and phosphorous • Made of repeating chains of nucleotides

16. Nucleic Acids • Nucleotides have 3 parts • Sugar • Phosphate • Nitrogenous base

17. ATP • Adenosine triphosphate • ATP is not one of the 4 major groups of organic molecules • ATP is essential to life – energy source