1. The Human Body – An Orientation
Anatomy – study of the structure and shape of the body and its parts
Physiology – study of how the body and its parts work or function
Metabolism – all chemical reactions within the body
Homeostasis - maintenance of a stable internal environment

2. Levels of Structural Organization
Figure 1.1

3. Biochemistry: Essentials for Life
Organic compounds
Contain carbon – except CO2, CO, CO3, HCO3
Most are covalently bonded
Examples: glucose, proteins, fats, DNA
Inorganic compounds
Lack carbon
Tend to be simpler compounds
Example: H2O (water)

4. Important Organic Compounds
Carbohydrates
Contain carbon, hydrogen, and oxygen in the ratio CH2O
Include sugars and starches
Classified according to size
Monosaccharides – simple sugars. Important fuel source for body cells. Building blocks of Carbohydrates. (Ex. Glucose, Fructose, Galactose)
Disaccharides – two simple sugars joined by dehydration synthesis. (Ex. Sucrose, Maltose, Lactose)
Polysaccharides – long branching chains of linked simple sugars. (Ex. Starch, Glycogen)

5. Contain carbon, hydrogen, and oxygen
Lipids
Contain carbon, hydrogen, and oxygen
Carbon and hydrogen outnumber oxygen
Insoluble in water
Common lipids in the human body
Neutral fats (triglycerides)
Found in fat deposits (body insulation)
Composed of fatty acids and glycerol
Source of stored energy

6. Phospholipids Steroids Form cell membranes
Include cholesterol, bile salts, vitamin D, and some hormones

7. Proteins
Made of amino acids.
Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur
20 different amino acids, 8 of which are essential.
Account for over half of the body’s organic matter. Main component of cellular cytoplasm.
STRUCTURAL PROTEINS - Provides for construction materials for body tissues (Collagen, Keratin)
FUNCTIONAL PROTEINS - Plays a vital role in cell function (Enzymes, Hemoglobin, Hormones)

8. Enzymes Act as biological catalysts
Increase the rate of chemical reactions
Figure 2.17

9. Nucleic Acids
Provide blueprint of life
Nucleotide bases
A = Adenine
G = Guanine
C = Cytosine
T = Thymine
U = Uracil
Make DNA (the stuff of genes) and RNA

10. Orientation and Directional Terms
Table 1.1

11. Orientation and Directional Terms
Table 1.1 (cont)

12. Body Landmarks
Anterior
Figure 1.5a

13. Body Landmarks
Posterior
Figure 1.5b

14. Cellular Physiology: Membrane Transport
Membrane Transport – movement of substance into and out of the cell
Transport is by two basic methods
Passive transport
No cellular energy is required (simple diffusion, osmosis)
Active transport
The cell must provide metabolic energy (endocytosis, exocytosis, solute pumping)

15. Selective Permeability
The plasma membrane allows some materials to pass while excluding others
This permeability includes movement into and out of the cell

16. Passive Transport Processes
Diffusion
Particles tend to distribute themselves evenly within a solution
Movement is from high concentration to low concentration, or down a concentration gradient
Figure 3.9

17. Passive Transport Processes
Types of diffusion
Simple diffusion
Unassisted process
Solutes are lipid-soluble materials or small enough to pass through membrane pores

18. Passive Transport Processes
Types of diffusion
Osmosis – simple diffusion of water
Highly polar water easily crosses the plasma membrane
Facilitated diffusion
Substances require a protein carrier for passive transport

19. Diffusion through the Plasma Membrane
Figure 3.10

20. Passive Transport Processes
Filtration
Water and solutes are forced through a membrane by fluid, or hydrostatic pressure
A pressure gradient must exist
Solute-containing fluid is pushed from a high pressure area to a lower pressure area

21. Active Transport Processes
Transport substances that are unable to pass by diffusion
They may be too large
They may not be able to dissolve in the fat core of the membrane
They may have to move against a concentration gradient
Two common forms of active transport
Solute pumping
Bulk transport

22. Active Transport Processes
Solute pumping
Amino acids, some sugars and ions are transported by solute pumps
ATP energizes protein carriers, and in most cases, moves substances against concentration gradients
Transports amino acids, sugars, and Na through the plasma membrane
ACTIVE TRANSPORT ANIMATION

23. Active Transport Processes
Bulk transport
Exocytosis
Moves materials out of the cell
Material is carried in a membranous vesicle
Vesicle migrates to plasma membrane
Vesicle combines with plasma membrane
Material is emptied to the outside

24. Exocytosis
Figure 3.12a

25. Active Transport Processes
Bulk transport
Endocytosis
Extracellular substances are engulfed by being enclosed in a membranous vescicle
Types of endocytosis
Phagocytosis – cell eating
Pinocytosis – cell drinking