Agenda 4/9 Cell Biology Review Notes Surface area to volume calculations Structures of eukaryotes and prokaryotes activity Homework: Cellular organelles video and notes, email me your study plan

Cell Theory 1. All organisms are composed of one or more cells 2. Cells are the smallest unit of life 3. All cells come from pre-existing cells Atypical Examples Striated Muscle-long and bigger than most cells, are multi- nucleated Giant Algae-very large for being a unicellular organisms Aseptate fungi-tube like structures contain many nuclei

Functions of Life Metabolism Growth Reproduction Homeostasis Response Excretion Nutrition

Limits to Cell Size Why are cells so small? In cells, the surface area to volume ratio is extremely important If you have a small surface area, and a big volume, transporting materials into and around the cell is difficult If you have a large surface area, and small volume, cell transport becomes a lot more efficient. Cells need a LARGE surface area to volume ratio

Microscopes Most cells cannot be seen with just our eyes Two main types of microscopes Light Microscope- inexpensive, simple to prepare specimen, magnifies up to 2000x, can observe living or dead specimens Electron Microscope- expensive, hard to prepare specimen, magnifies up to 500,000x, specimens must be dead

Types of Cells Prokaryotes (Bacteria and Archaea) Have: plasma membrane, DNA, 70s ribosome, pili, flagella, cell wall, nucleoid region Missing: nucleus, other membrane bound organelles Eukaryotes (Plants, Animals, Fungi) Have: plasma membrane, DNA, 80s ribosome, nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes etc. Some eukaryotes have a cell wall