Molecules in Our Bodies

pH pH = Power of Hydrogen Logarithmic Scale: 0-14 Shows concentration of H+ ions in water Water dissociates into H + and OH - 10^-7 H + in normal water: pH 7 = neutral Acids (0-6) and Bases (8-14) Controls enzymes and reactions

Feedback Homeostasis: We must maintain a stable internal environment (balance). Positive vs. Negative Feedback Example: Temperature Is temperature a positive or negative feedback loop? Molecules help us maintain balance!

Digestion How do we get energy and nutrition from our food?40.3 (p. 828) and 41.2 (p. 849) Why do we pee? 44.2 (p.927) (also kidneys)

Respiration How do we get oxygen to our cells and get rid of the carbon dioxide waste?42.7 (p.891)

Health/Immunity What is the role of chemical receptors in our immune system’s ability to fight off disease? 43.2 (p.903) How does the misrecognition of molecules create allergies and autoimmune diseases?43.5 (p.916)

Reproduction Why do women get periods?46.4 (p.973) How do hormones control the development of a zygote into an embryo?47.1 (p. 989)

Growing Up How do hormones communicate with your cells to regulate growth and reproduction? 45.2 (p. 945)

Processing Information How do brain cells send signals? 48.3 and 48.4 (p.1017)