1. Cytology Biochemistry – Chap. 2 Cell Biology – Chap. 3

2. Learner Outcomes: To describe the characteristics and identify the monomers of lipids, proteins, carbohydrates, and nucleic acids and to define their role in biochemical processes. To analyze and explain the chemical reactions that provide energy for the body. To investigate and describe the integration of the chemical and physical properties that contribute to homeostasis in cells. To compare the structures and functions of organelles within cells of the body. To describe the processes involved in the cell cycle.

3. Importance of Water Properties:  It is polar (H+ hydrogen ion & OH- hydroxide ion)  Held together by Hydrogen Bonds - relatively weak; can be broken easily.

4. Characteristics of H2O- Why important in Living Systems 1. Universal solvent  aids in ionization of salts and electrolytes within the body. 2. Cohesive  allows blood vessels to be filled; even distribution throughout body. 3. High heat of vaporization  resistant to change; helps maintain homeostasis of body temp.

5. Acids & Bases Acids – dissociate in water; release hydrogen ions (H+)  Ex’s: lemon juice, hydrochloric acid, coffee, tomatoes, vinegar Bases – take up H+ ions or release hydroxide ions (OH-).  Ex’s: milk of magnesia, ammonia

6. pH Scale

7. pH of body fluids needs to be maintained within a narrow range, or health suffers. Ave. pH of blood is 7.4 Buffers are built-in mechanisms to prevent pH changes.  chemicals or combos of that take up excess H+ ions or hydroxide ions. - ex: combo of carbonic acid (H2CO3) & bicarbonate ion (HCO3) help maintain pH of blood. Q: How does water play a role in this process?