BIO 213 Chapter 5 Practice Questions with 100% Correct Answers

the cell theory first unifying theory of biology - three critical components: - cells are the fundamental units of life - all organisms are composed of cells - all cells come from pre-exisiting cells implications of the cell theory: - functions of all cells are similar - life is continuous - origin of life was the origin of cells surface area to volume ratio Volume determines the amount of chemical activity in the cell per unit time. Larger cells have more chemical activity. light microscopes type of microscopes that uses glass lenses and light (living cells) electron microscopes electromagnets focus on electron beam - resolution is better (dead cells) scanning electron microscopes allows a detailed study of the surface of a specimen transmission electron microscope used to study the internal ultrastructure of cells magnification increases apparent size resolution clarity of magnified object (resolution of human eye is 0.2 mm) plasma membrane outer surface of every cell (same structure in all cells) made of phospholipid bilayer with embedded proteins not rigid, more like an oily fluid in which the proteins are in constant motion characteristics of plasma membrane - selectively permeable barrier - allows cells to maintain a constant internal environment (homeostasis) - important in communication and receiving signals - often has proteins for binding and adhering to adjacent cells cytoplasm - the area enclosed by the plasma membrane excluding the contents of the nucleus - biochemical pathways: GLYCOLYSIS