Larry Frolich, Molecules and Diffusion Diffusion and the Molecules of Life Levels of Hierarchy and Organization in Living Systems and Multi-cellular organisms

Larry Frolich, Molecules and Diffusion Molecules of Life C-chainComponentMain Functions

Larry Frolich, Molecules and Diffusion Anatomy and Physiology in the Hierarchy of Life Molecules Cells Tissues Organs/Structures Organ Systems Organisms Environment

Larry Frolich, Molecules and Diffusion Levels of Organization within Human Body

Larry Frolich, Molecules and Diffusion Levels of Organization Chemical Level (Organic Chemistry and Biochemistry Cellular Level (Intro. Or Cell Biology): organelles, genes, mitosis, meiosis Tissue Level (Histology): groups of cells with common function—classes of tissues, epithelia (covering), connective tissues (support, protection) Organ Level (Anatomy): how tissues combine to form structures in body— lungs, bones, blood vessels, etc. Organ System level (Physiology) How organs and structures work together to accomplish specific functions: e.g., circulatory system, nervous system, skeletal system, etc. Organism: Entire body working together (Ecology or physiology in environment)

Larry Frolich, Molecules and Diffusion The importance of Diffusion Diffusion versus Osmosis (diffusion across a membrane) Diffusion fast and effective across microscopic distance Virtually all living processes involve diffusion and/or osmosis Cell membranes control diffusion and allow for life chemical reactions to take place Diffusion lets tissues do job and permits organ systems to function Examples: –Oxygen in circulatory system –Food in digestive system –Calcium in muscular function –Nerve impulses Cell membranes and Diffusion

Larry Frolich, Molecules and Diffusion Body Systems and Diffusion Understand path through body of: Food/Nutrients (glucose) Oxygen Carbon Dioxide Nitrogen

Larry Frolich, Molecules and Diffusion Homeostasis “…the ability to maintain relatively constant internal conditions even though the outside world changes continuously…” Within cells Within body

Larry Frolich, Molecules and Diffusion Feedback Mechanisms Negative Feedback Examples –home heating system –Glucose regulation in blood Positive Feedback Examples –Fire-Starting –Blood clotting

Larry Frolich, Molecules and Diffusion Web Links Cellular basis of physiology Diffusion/Osmosis animation

Larry Frolich, Molecules and Diffusion Next Time: Overview of Body Systems